Standard Electrode Coaxial Ge Detectors (SEGe)

Description

The conventional coaxial germanium detector is often referred to as Pure Ge, HPGe, Intrinsic Ge, or Hyperpure Ge. Regardless of the superlative used, the detector is basically a cylinder of germanium with an n-type contact on the outer surface, and a p-type contact on the surface of an axial well. The germanium has a net impurity level of around 1010 atoms/cc so that with moderate reverse bias, the entire volume between the electrodes is depleted, and an electric field extends across this active region. Photon interaction within this region produces charge carriers which are swept by the electric field to their collecting electrodes, where a charge sensitive preamplifier converts this charge into a voltage pulse proportional to the energy deposited in the detector.

The n and p contacts, or electrodes, are typically diffused lithium and implanted boron respectively. The outer n-type diffused lithium contact is about 0.5 mm thick. The inner contact is about 0.3 µm thick. A surface barrier may be substituted for the implanted boron with equal results.

The CANBERRA Coaxial Ge detector can be shipped and stored without cooling. However, long term stability is best preserved by keeping the detector cold. Like all germanium detectors, it must be cooled when it is used to avoid excessive thermally-generated leakage current. The non-perishable nature of this detector widens the application of Ge spectrometers to include field use of portable spectrometers.

The useful energy range of the Coaxial Ge detector is 40 keV to more than 10 MeV. The resolution and peak shapes are excellent and are available over a wide range of efficiencies. A list of available models is given in the accompanying table.

FeaturesStandard Electrode Coaxial Ge Detectors (SEGe)

  • Energy range from 40 keV to >10 MeV
  • High resolution – good peak shape
  • Excellent timing resolution
  • High energy rate capability
  • Diode FET protection
  • Warm-up/HV shutdown
  • High rate indicator

Coaxial Ge Detector Configuration

 

 

 

Broad Energy Germanium Detectors (BEGe)

Description

The CANBERRA Broad Energy Ge (BEGe) Detector covers the energy range of 3 keV to 3 MeV like no other. The resolution at low energies is equivalent to that of our Low Energy Ge (LEGe) Detector and the resolution at high energy is comparable to that of good quality coaxial (SEGe) detectors.

Most importantly the BEGe has a short, fat shape which greatly enhances the efficiency below 1 MeV for typical sample geometries. This shape is chosen for optimum efficiency for real samples in the energy range that is most important for routine gamma analysis. This is in stark contrast to the traditional relative efficiency measurement – a 60Co point source at 25 cm which is hardly a relevant test condition for real samples. See the figures below comparing absolute detector efficiencies of a 5000 mm² and 6500 mm² BEGe Detector to coaxial detectors with approximately 60% relative efficiency.

In addition to higher efficiency for typical samples, the BEGe exhibits lower background than typical coaxial detectors because it is more transparent to high energy cosmogenic background radiation that permeates above ground laboratories and to high energy gammas from naturally occurring radioisotopes such as 40K and 208Tl (thorium). This aspect of thin detector performance has long been recognized in applications such as actinide lung burden analysis.

Most Low Energy Detectors are aptly named because they do not give good resolution at higher energies. In fact resolution is not usually specified above 122 keV. The BEGe represents a breakthrough in this respect. The BEGe is designed with an electrode structure that enhances low energy resolution and is fabricated from select germanium having an impurity profile that improves charge collection (thus resolution and peak shape) at high energies. Indeed, this ensures good resolution and peak shape over the entire mid-range which is particularly important in analysis of the complex spectra from uranium and plutonium.

In addition to routine sample counting, there are many applications in which the BEGe Detector really excels. In internal dosimetry the BEGe gives the high resolution and low background need for actinide lung burden analysis and the efficiency and resolution at high energy for whole body counting. The same is true of certain waste assay systems particularly those involving special nuclear materials.

The BEGe detector and associated preamplifier are normally optimized for energy rates of less than 60 000 MeV/sec. Charge collection times prohibit the use of short amplifier shaping time constants. Resolution is specified with an optimum shaping time constant and Lynx® digital peaking time equivalent.

Another big advantage of the BEGe is that the detector dimensions  are virtually the same on a model by model basis. This means that like units can be substituted in an application without complete recalibration and that computer modeling can be done once for each detector size and used for all detectors of that model.

With cross-sectional areas of 20 to 65 cm2 and thickness’ of 20 to 30 mm, the nominal relative efficiency is given below along with the specifications for the entire range of models. BEGe detectors are normally equipped with our composite carbon windows which are robust and provide excellent transmission to below 10 keV. Beryllium or aluminum windows are also available. Aluminum is preferred when there is no interest in energies below 30 keV and improved ruggedness is desired. Beryllium should be selected to take full advantage of the low energy capability (down to 3 keV) of the BEGe detector.

Features & Benefits

  • Energy range from 3 keV to 3 MeV combines the spectral advantages of Low Energy and Coaxial HPGe detectors
  • Detection efficiencies and energy resolutions are optimized in the 3 keV to 662 keV energy region where most tightly-grouped gamma lines of interest are located
  • Flat, non-bulletized crystals offer optimum efficiencies for samples counted close to the detector
  • Thin, stable entrance window allows the detector to be stored warm with no fear of low energy efficiency loss over time

Broad Energy Germanium Detectors (BEGe)
Broad Energy Germanium Detectors (BEGe)
Absolute Efficiency vs. Energy comparison for BE6530, BE5030, GC6020 (p-type coaxial) and GR6022 (n-type coaxial) detectors
Broad Energy Germanium Detectors (BEGe)
Absolute Efficiency vs. Energy Comparison for BE6530, GR6022 (n-type coaxial) and GC6020 (p-type coaxial) detectors – all with 60% Relative Efficiency @ 1332 keV

 

 

 

 

 

 

Reverse Electrode Coaxial Ge Detectors (REGe)

Description

The reverse-electrode detector (REGe) is similar in geometry to other coaxial germanium detectors with one important difference. The electrodes of the REGe are opposite from the conventional coaxial detector in that the p-type electrode, (ion-implanted boron) is on the outside, and the n-type contact (diffused lithium) is on the inside. There are two advantages to this electrode arrangement – window thickness and radiation damage resistance.

The ion-implanted outside contact is extremely thin (0.3 μm) compared to a lithium-diffused contact, enabling the REGe detector to cover a broad energy range from 3 keV up to several MeV. REGe detectors are normally equipped with a carbon composite window which is robust and provides excellent transmission to below 10 keV. Beryllium or aluminum windows are also available. Aluminum is preferred when there is no interest in energies below 20 keV and improved ruggedness is desired. Beryllium should be selected to take full advantage of the low energy capability (down to 3 keV) of the REGe detector.

It has been found that radiation damage, principally due to neutrons or charged particles, causes hole trapping in germanium. Unlike the case of the conventional coaxial detector, holes are collected by the outside electrode of the REGe detector. Since a much greater amount of the active detector volume is situated within a given distance, ∆ R, of the outside contact, than of the inside contact (Volume ≈ R2) it follows that, on average, holes have less distance to travel if they are attracted to the outside contact than if they are attracted to the inside contact. With less distance to travel, they are less likely to be trapped in radiation damaged material. The extent of the improved resistance to radiation damage depends on other facts, of course, but experimental evidence suggests that the REGe detector may be 10 times as resistant to damage as conventional coaxial germanium detectors.

FeaturesReverse Electrode Coaxial Ge Detectors (REGe)

  • Spectroscopy from 3 keV to >10 MeV
  • Ultra-thin ion implanted
    contacts
  • Radiation damage resistant
  • Excellent timing resolution
  • High energy rate capability
  • Diode FET protection
  • Warm-up/HV shutdown
  • High rate indicator

REGe Detector Configuration

 

 

 

Extended Range Coaxial Ge Detectors (XtRa)

Description

The CANBERRA XtRa is a coaxial germanium detector having a unique thin-window contact on the front surface which extends the useful energy range down to 3 keV. Conventional coaxial detectors have a lithium-diffused contact typically between 0.5 and 1.5 mm thick. This dead layer stops most photons below 40 keV or so rendering the detector virtually worthless at low energies. The XtRa detector, with its exclusive thin entrance window and with a Carbon Composite cryostat window, offers all the advantages of conventional standard coaxial detectors such as high efficiency, good resolution, and moderate cost along with the energy response of the more expensive Reverse Electrode Ge (REGe) detector.

The response curves (below) illustrate the efficiency of the XtRa detector compared to a conventional Ge detector. The effective window thickness can be determined experimentally by comparing the intensities of the 22 keV and 88 keV peaks from109Cd. With the standard 0.6 mm Carbon Composite window, the XtRa detector is guaranteed to give a 22 to 88 keV intensity ratio of greater than 20:1. Beryllium and aluminum windows are also available.

FeaturesExtended Range Coaxial Ge Detectors (XtRa)

  • Spectroscopy from 3 keV to >10 MeV
  • Wide range of efficiencies
  • High resolution – good peak shape
  • Excellent timing resolution
  • High energy rate capability
  • Diode FET protection
  • Warm-up/HV shutdown
  • High rate indicator

XtRa Coaxial Ge Detector

 

 

 

 

 

Small Anode Germanium Well Detectors (SAGe Well)

Description

The CANBERRA SAGe™ Well Detector combines excellent energy resolution at low and high energies with maximum efficiency for small samples. Like Traditional Well Detectors, the SAGe Well is fabricated with a blind hole, leaving at least 20 mm of active detector thickness at the bottom of the well. The counting geometry therefore approaches 4p.

The low detector capacitance associated with the small anode technology (similar to what is used on CANBERRA’s BEGe detectors) gives the SAGe Well superior low and medium-energy resolution performance compared to Traditional Well or Coaxial Detectors, as well as excellent resolution for higher energy gamma rays.

Furthermore, the detector is manufactured with an aspect ratio of a coaxial detector to allow excellent efficiency performance for standard laboratory geometries such as Marinelli beakers or other large sample containers. The result is a versatile detector that can deliver reductions in count time, through improvements in Minimum Detectable Concentration/Activity (MDC/MDA), for a range of sample sizes and geometries counted inside the well, on the end cap or in Marinelli beakers.

The thin lithium (approximately 50 µm) diffused contact inside the well, combined with a thin-walled aluminum insert in the detector end cap (0.5 mm on the sides and a 1 mm thick bottom) provide a good low-energy response, allowing spectroscopy down to 20 keV. The contact on the outer surface of the detector is approximately 0.5 mm thick, similar to what is used on Standard Electrode Germanium (SEGe) coaxial detectors. Therefore, the useful energy range for sources outside of the well is limited to 40 keV and up.

Small Anode Germanium Well Detectors (SAGe Well)

Features / Benefits

  • Blind well approaches 4p counting geometry yielding high absolute efficiency
  • Superior resolution compared to Traditional Well Detectors at both low and high energies
  • Larger well diameter (28 mm) available with the same excellent resolution as the standard (16 mm) well sizes
  • Thin lithium diffused contact inside well allows spectroscopy from 20 keV up to 10 MeV
  • Full LabSOCS™ characterization available, allowing True Coincidence Summing correction

Applications

  • Environmental samples
  • Radiobioassay
  • Geology
  • Oceanography

 

 

Traditional Germanium Well Detectors

Description

The CANBERRA High-Purity Germanium (HPGe) Well Detector provides maximum efficiency for small samples because the sample is virtually surrounded by active detector material. The CANBERRA Well detector is fabricated with a blind hole rather than a through hole, leaving at least 15 mm of active detector thickness at the bottom of the well. The counting geometry therefore approaches 4π.

The Well insert in the endcap is made of aluminum with a side-wall thickness of 0.5 mm and a 1 mm thick bottom. The ion implanted contact on the detector element is negligibly thin compared to 0.5 mm of aluminum so these detectors have intrinsically good low energy response, allowing spectroscopy down to 20 keV.

Applications

  • Environmental samplesGermanium Well Detectors (WELL)
  • Geology
  • Oceanography
  • Life sciences

Features / Benefits

  • Blind well approaches 4π counting geometry yielding high absolute efficiency
  • Large variety of models available allowing to select the optimum Well detector for your application
  • Thin, ion-implanted contact inside Well allows spectroscopy from 20 keV up to 10 MeV

 

 

 

Low Energy Germanium Detectors (LEGe)

Description

The Low Energy Germanium Detector (LEGe) is in all aspects optimized for performance at low and moderate energies and has specific advantages over conventional planar or coaxial detectors. The LEGe detector is fabricated with a thin front and side contact. The rear contact is of less than full area which gives a lower detector capacitance compared to a planar device of similar size. Since preamplifier noise increases with detector capacitance, the LEGe affords lower noise and consequently better resolution at low and moderate energies than any other detector geometry. Unlike grooved planar detectors, there is little dead germanium beyond the active region. This, and the fact that the side surface is charge collecting rather than insulating, results in fewer long-rise time pulses with improved count rate performance and peak-to-background ratios.

The LEGe detector is available with active areas from 50 mm2 to 2000 mm2 and with thicknesses ranging from 5 to 20 mm. For applications involving moderate gamma-ray energies, the LEGe may well outperform a more expensive large volume coaxial detector. The efficiency curve given below illustrates the performance of a typical LEGe detector.

To take full advantage of the low energy response of this intrinsically thin window detector, LEGe cryostats are usually equipped with a thin (1 to 20 mil) beryllium window. A LEGe cryostat can also be equipped with a 0.6 mm carbon epoxy window which improves ruggedness over the Be window, but still has a good low energy transmission. For applications at energies above 30 keV, the LEGe can be provided with a conventional 0.5 mm Aluminum window. In any case, a wide range of available CANBERRA cryostats allows optimizing the detector configuration for your application.

Features & Benefits

  • Thin front and side contact, allowing spectroscopy from 3 keV up
  • Wide range of sizes allows selecting the best detector for your application
  • Low noise and consequently high resolution at low and moderate energies

 

Applications

  • Low energy gamma spectroscopy
  • X-ray absorption spectroscopy
  • Nuclear safeguards
  • XRD, XRF

 

 

 

Ultra-LEGe Detectors (GUL)

Description

The CANBERRA Ultra-LEGe detector extends the performance range of Ge detectors down to a few hundred electron volts, providing resolution and peak-to-background ratios once thought to be unattainable with semiconductor detectors. The Ultra-LEGe retains the high-energy efficiency intrinsic to germanium detectors because of the high atomic number (Z), combined with a relatively high thickness (5-10 mm), and thus covers an extremely wide range of energies. The graph in Figure 2 below compares the efficiency on the high-energy side of the X-ray spectrum of a 5 mm thick germanium detector to typical silicon based detectors.

Conventional Ge detectors, including those made especially for low energies, suffer from poor peak shape and efficiency below 3 keV. This characteristic, once thought to be fundamental to Ge, prohibited use of Ge detectors in most analytical x-ray applications. CANBERRA has developed detector fabrication techniques which have eliminated these problems. The resulting detector, the Ultra-LEGe, delivers the intrinsic efficiency and resolution advantages of germanium without the disadvantages of the conventional germanium detector.

Features & Benefits

  • Spectroscopy from 300 eV to 300 keV
  • High efficiency compared to Si(Li) and SDD
  • Excellent resolution up to very high count rates
  • High peak/background ratio

 

Applications

  • XRF
  • XAS (XAFS, EXAFS, XANES)
  • X-ray spectroscopy

 

 

ACT-II Actinide Ge Detectors

Description

The CANBERRA ACT-II Ge Detector was designed specifically for the detection of internally deposited actinides, particularly uranium, plutonium and americium. Because of the low gamma-ray abundance from uranium, and the low energy of the x rays from plutonium, which emits few gammas, this application demands a very specialized detector system. To achieve desired sensitivities, four detectors are placed in virtual contact with the subject in close proximity to the lungs. The measurement must be carried out in a shielded room. For optimum results, the detectors must be closely spaced, the detector background must be low, the resolution must be good, and the sensitivity of the detector must be high over the energy range of interest (13-20 keV for Pu, 60 keV for Am, and 140-190 keV for U). The ACT-II Ge Detector from CANBERRA provides all this performance and more.

FeaturesACT-II Actinide Ge Detectors

  • Specialized detector system for difficult-to-detect internally deposited actinides
  • Closely-spaced detectors with low background
  • Excellent resolution and high-sensitivity at low to moderate energies
  • Operates in all attitudes from vertical upright to vertical downlooking

 

 

 

Germanium Array Detectors

Description

The broad-band x-ray flux from synchrotron radiation sources has revitalized the relatively old experimental technique known as x-ray absorption spectrometry. X-ray absorption spectroscopy measures the attenuation of an x-ray beam passing through a sample, just as do the more familiar infrared or UV-visible techniques. Typical x-ray energies are on the order of 300 eV to 30 keV or more, compared to visible light of 2–3 eV and infrared energies of about 0.05–0.5 eV. High energy x-ray absorption transitions involve core electrons which are only slightly perturbed by chemical changes in the valence electrons, hence each element has characteristic absorption edges at which the x-ray energy is just sufficient to liberate a particular type of core electron. Since edges are generally well separated in energy, x-ray absorption is a technique which can uniquely probe the environment of any element from carbon through the transuranics. A generalized x-ray absorption spectrum is illustrated at right.

CANBERRA has been the leader in the development and production of Germanium Array Detectors for this application. Herein you will find a brief summary of our capabilities and products.

Discrete or Monolithic – Both from CANBERRA

Germanium Array Detectors

Discrete Array Detectors

Most of the x-ray array detectors manufactured by CANBERRA have been made with discrete LEGe or Ultra-LEGe detector elements coupled to reset preamplifiers. Because of the high count rates involved, the Integrated- Transistor Reset Preamp (I-TRP) is used exclusively in this application. The discrete element detectors take full advantage of the performance characteristics of LEGe and Ultra-LEGe detectors, notably the energy resolution with short pulse processing (shaping) times. These detectors operate well with shaping time constants of 1/8 μs and up. The Ultra-LEGe detector extends the usable energy range down to 300 eV or so, depending on the cryostat window. Because of the difficulty in handling large numbers of detector elements, discrete array detectors are limited to about 36 channels.

Monolithic Array Detectors

CANBERRA now has the capability to make segmented planar Ge detectors using advanced photolithographic techniques. This technology lends itself to the production of pixel detectors wherein multiple elements are formed in a single slice of germanium. Monolithic array detectors offer improved packing density compared to discrete array detectors. The packing density is defined as the active detector area divided by the total area circumscribed by the array. Monolithic detectors, which have no dead space between elements, have virtually 100% packing density. The packing density of discrete array detectors ranges from about 35 to 55%. Packing density is an important factor in applications requiring an optimized solid angle and best fit to detection area.

 



 

Electrically-cooled Cryostats

DescriptionCryo-Cycle™ II "Hybrid" Cryostat

CANBERRA’s two electrically-cooled cryostats eliminate the need to constantly refill HPGe detector LN2 Dewars. This means less hassle, enhanced safety and a time-consuming chore crossed off your “to-do” list.

Cryo-Cycle II Hybrid Cryostat

Our Cryo-Cycle™ II “Hybrid” Cryostat has a 25-liter LN2 reservoir for continued operation in case of power failure — it can typically operate for over a year before adding more gaseous or liquid nitrogen.

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Cryo-Pulse® 5 Plus Electrically Refrigerated Cryostat

Cryo-Pulse® 5 Plus Electrically Refrigerated Cryostat

Our compact Cryo-Pulse® 5 Plus Electrically Refrigerated Cryostat employs only electrical cooling and requires no LN2.

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Slimline Cryostats

Description

CANBERRA Slimline cryostats are designed so that the detector and electronics both fit in a cylindrical housing without any protruding flanges, valves, and preamplifier enclosures.

This compact configuration facilitates integration into shields and systems. Maintenance or exchange of the preamplifier is also very simple as it is located underneath the cylindrical cover, outside of the cryostat vacuum.

Vertical Slimline Dipstick cryostats can be fitted with a Remote-Detector Chamber (RDC). This RDC option separates the detector chamber from the Dewar and preamplifier and allows the use of a backshield so the lead shield completely surrounds the detector element.

Additionally the offset between the centerline of the RDC element and the cryostat coldfinger removes any direct “line-of-sight” between the detector chamber and the molecular sieves.

This design significantly reduces the radiation background on the detector. Standard lengths for the RDC option are 2, 4, 6, 8 and 10 inches. Custom lengths are available upon request.

End cap dimensions depend on detector size. The chart below shows the typical efficiency range vs. end-cap diameter. End cap lengths are also greater for larger detectors. Consult the factory if end-cap size is critical in your application.

Rel. Efficiency (%) Diameter in. (mm)
≤40 3.0 (76)
40-50 3.25 (83)
50-70 3.50 (89)
70-100 3.75 (95)
≥100 4.0 (102)

Flanged Cryostats

The liquid nitrogen cryostat is the most important and least appreciated component in assuring reliable long term performance of a germanium detector system. CANBERRA manufactures its own cryostats to exacting quality standards to ensure long detector life.

There are two basic types of cryostats in use: the dipstick, in which the detector occupies a vacuum chamber having a dipstick-like tail which is inserted into the neck tube of a Dewar, and the integral, in which the detector chamber and Dewar share a common vacuum.

The standard configuration comes with a radial O-ring seal. A metal face seal is available as an option on detectors with a 3.0 in. (76 mm) diameter endcaps only. Metal seals are more rugged and, in general, provide a longer life time of the detector vacuum.

Flanged cryostats can be fitted with a Remote-Detector Chamber (RDC). This RDC option separates the detector chamber from the Dewar and preamplifier and allows the use of a backshield so lead shielding that completely surrounds the detector element can be installed.

This significantly reduces the radiation background on the detector. Standard lengths for the RDC option are 2, 4, 6, 8 and 10 inches. Custom lengths are available on request.

End cap dimensions depend on detector size. The chart below shows the typical efficiency range vs. end-cap diameter. End cap lengths are also greater for larger detectors. Consult the factory if end-cap size is critical in your application.

Rel. Efficiency (%) Diameter in. (mm)
≤40 3.0 (76)
40-50 3.25 (83)
50-70 3.50 (89)
70-100 3.75 (95)
≥100 4.0 (102)

 

Portable Cryostats

Description

For applications requiring both portability and flexibility of use, the MAC (multi-attitude cryostat) is the answer. The unique fill and vent system employed by the MAC allows operation of the detector in any orientation without LN2 spillage even when the Dewar is full. The small size, light weight, and ruggedness of the unit permit use of the unit in field conditions. The slimline detector chamber allows the unit to be shielded very effectively for use in low level counting applications.

The MAC detector consists of a Dewar having two fill and vent ports arranged so that one of the ports is the vent, regardless of the Dewar’s orientation. This allows the Dewar to be operated in the horizontal position, vertically uplooking, or vertically downlooking, without loss of LN2.

A single port version of the MAC and Big MAC is available on special order. This version has half the capacity and holding time of the standard product. A gravity-feed supply Dewar/stand is available for the single port cryostat. The single port cryostat is compatible with other brands, and it holds LN2 in all orientations which may be important in some applications, e.g. for use in a submarine (see CANBERRA Model 7411).

The detector/preamp includes a sensor which provides a signal when the LN2 is depleted. This output can be used to shut down the bias supply, to operate an alarm, or both.

Features

  • Operation in any orientation
  • Light weight aluminum construction
  • Slimline detector/preamplifier configuration
  • Long holding time
  • Warm-up sensor-bias disable

Portable Cryostat

The standard MAC features CANBERRA’s slimline cryostat option in which a CANBERRA preamplifier is packaged behind the detector chamber within the confines of the 80 mm diameter snout. The slimline cryostat allows the detector to be installed in a shield with very little difficulty and with efficient use of shielding material. The snout is long enough to reach through 10-15 cm of shielding material and still accommodate Marinelli beaker samples.

A flanged version of the MAC is also available. This version makes use of a conventional box style preamplifier having bulkhead connectors (rather than pigtail connectors) and is somewhat more compact than the slimline version.

The MAC comes with detachable carrying handle assembly. With the carrying handle assembly removed, there are no obstructions beyond the outer diameter of the Dewar, and the unit can be readily installed in other scientific apparatus such as whole-body counters, scattering chambers or low-level counting systems.

Both manual and automatic refill systems are available for use with the MAC. Since the MAC has separate fill and vent ports, the LN2 supply and the vent lines can be made gas tight, thus avoiding the hazards of cold N2 or LN2to either personnel or adjacent equipment.

The MAC is available as an option with most of the High Purity Germanium detectors offered by CANBERRA. Consult the CANBERRA Catalog for information on the wide variety of detectors that are available from CANBERRA.

Retractable Cryostats

Description

These retractable cryostats from CANBERRA are used with Si(Li), LEGe, and Ultra-LEGe detectors in x-ray applications. Retractable cryostats provide a means of moving the detector element in relation to the sample with both under vacuum. They also make it possible to operate the detector in windowless mode, i.e. without a window (absorber) between the detector element and the sample.

As with any detector that is not permanently sealed, care must be exercised in using windowless detectors to avoid contamination of the detector element. The vacuum chamber to which the detector is attached must be clean and dry and under good vacuum before the gate valve is opened. Under no circumstances is the detector to be exposed to atmosphere while it is cold. Damage to detectors caused by contamination is not covered under warranty.

Features

  • Variable geometry
  • Windowless operation
  • UHV compatible
  • Rugged and reliable
  • Use with Si(Li) or Ge detectors

LN2 Gauge/Controller Model 7185/7186

Description

The Model 7185 LN2 Level Gauge provides a digital display of LN2 level in a Dewar or container along with adjustable low and high level setpoints which initiate audible and visible alarm signals as well as a relay output for remote monitoring. The display shows liquid level from 0-100% of the active sensor length. It can be programmed to read out in inches or centimeters. Sensors are designed, sized, and configured for CANBERRA dipstick and integral cryostats. For portable cryo-stats refer to the Model 2541 Controller. Consult the factory for applications involving non-CANBERRA cryostats.

The Model 7186 provides the same functions as the 7185. In addition it has adjustable low and high level control setpoints and a relay which provides line voltage to a controlled ac output for operation of a solenoid valve. The control and alarm setpoints are readily adjustable by means of front panel controls. Setpoints are stored in non-volatile memory. This ac outlet is powered from the time the low setpoint is reached until either 1.) the high setpoint is reached or 2.) the user-programmed time-out is reached. The 7186 includes a cryogenic solenoid valve as well as fill and vent hoses. LN2 supply containers are available from CANBERRA for a complete automatic LN2 Fill System.

Both models operate on line voltage of 100, 115, 200, or 240 V ac, 50 or 60 Hz, internally selected. This line voltage is provided on the controlled ac outlet.

The 7186 Controller requires a source of LN2 at a pressure of 34 to 172 kPa gauge (5 to 25 psig). CANBERRA D-160 and D-240 containers or their equivalents are highly recommended. A self-pressurizing withdrawal device (NTD-30/50) with a 30 or 50 liter Dewar can be used but it is not highly recommended because of marginal capacity and pressure for most applications. The liquid quality must be good at the point of consumption. This means there must be no ice in the liquid and that the supply line must not be lossy (causing excess vaporization).

An overflow container may be required if there is no safe place for the discharge of overflow gas and liquid. WARNING: Malfunctions can result in the entire contents of supply containers being dumped through the system. CANBERRA takes no responsibility for such accidents. The user is responsible for the installation and for the safety measures that are needed in this application.

Features

Models 7185 and 7186

  • Digital level displayModel 7185
  • High and low alarm setpoints
  • Audible and visible alarm
  • Alarm relay
  • Sensor tailored to cryostat

Model 7186 Only

  • High and low control setpoints
  • Controlled ac output
  • Solenoid valve with captive 3 m (10 ft) cord
  • Hoses for fill and vent

 

Detector LN2 Monitor Model 1786A

Description

The Model 1786A Detector LN2 Monitor protects LN2-cooled detector systems against accidental warmup by monitoring liquid level in the Dewar and providing audible and visual warning of low liquid levels. It provides a signal for remote shutdown of Detector Bias Supply which has an Inhibit input. This singlewidth NIM module is suitable for most dipstick and integral type cryostats, but is not suitable for portable cryostats.

When your LN2 sensor detects a problem, the LN2Monitor has provisions for turning off high voltage when an alModel 1786arm condition occurs to protect detectors and electronics from damage. Shutdown does not occur until at least 20 minutes after the condition is sensed, and well before total depletion of the liquid nitrogen, so ongoing experiments can continue without interruption.

The Model 1786A must be manually reset following a power interruption. This will prevent HV Bias from coming on automatically (and abruptly) when the power is restored.

Features

  • Automatic protection against accidental detector warmup
  • Delayed shutdown saves experiments
  • Audible, visual and contact closure outputs

LN2 Accessories

Model D-2 LN2 Fill Device

  • Self-pressurizing device for filling portable cryostats
  • Uses non-pressurized LN2
  • Capacity – 2 liters
  • Two charges fill MAC, 5-6 charges fill Big MAC

Model D-160 LN2 Storage Tank

  • 160 liter capacity
  • 152 kPa (gage) (22 psig) relief
  • 1.5% per day loss rate
  • Diameter – 51 cm (20 in.)
  • Shipping weight 100 kg (220 lb) empty

Model D-30; D-50 LN2 Storage Dewar

  • LN2 capacity (liters) -30/50
  • Diameter – 43 cm (17 in.)
  • Height – 61.5/89.4 cm (24.2/35.2 in.)
  • Loss rate (liters per day) – 0.5/0.6
  • Shipping weight 11.8 kg (26 lb)

Model NTL-6 Nitrogen Transfer Line

  • Insulated latex transfer line
  • 3/ 8 in. ID x 1/ 8 in. wall x 6 ft long

Model D-30/OS Offset Neck Dewar

  • Provides horizontal offset to detector chambers
  • Neck to be offset by 12.7 cm (5 in.)
  • Replaces D-30 Dewar in dipstick cryostats

Model D-240 LN2 Storage Tank

  • 240 liter capacity
  • 152 kPa (gage) (22 psig) relief pressure
  • 1.0% per day loss rate
  • Diameter – 66 cm (26 in.), height – 1.63 m (64 in.) (with casters)
  • Shipping weight 122 kg (270 lb), empty

Model NTD-30; NTD-50 LN2 Withdrawal Device

  • NTD-30 for use with D-30
  • NTD-50 for use with D-50
  • Pressure gauge
  • 34.5 kPa (gage) (5 psig) relief valve
  • Manual LN2 valve
  • Shipping weight 2.7 kg (6 lb)

Model RB-1 Roller Base for D-30 or D-50

  • Adjustable
  • Stable four-wheel design

Low Background Detector Systems

Introduction

The term “low background” is used fairly indiscriminately in describing gamma analysis systems. The one common denominator for such systems is some form of shielding, but beyond this, anything goes. To bring some order to our own product line and to help customers distinguish the classes of systems, CANBERRA has chosen to categorize low-background gamma analysis systems as follows:

Low-Background

Ge detectors in a variety of cryostat types with lead shielding of 2-4 inch (5-10 cm) thickness. The only cryostats specifically excluded from this class are modular (convertible) types in which the molecular sieve adsorber is necessarily located near the detector element.

Ultra Low-Background

Ge detectors in cryostats that are A: designed for shielding effectiveness and B: constructed from materials that are notably low in background. The complementary lead shields are also made from select, low-background materials and are at least 4-6 inches (10-15 cm) thick. CANBERRA uses the term Ultra Low-Background to describe standardized detectors and shields which are described in the following pages. These standard products offer performance normally associated with much more expensive custom systems.

See more information on the Ultra Low-Background Cryostats (ULB) section that follows (or click here).

Specialty Ultra Low-Background

Systems in this class are designed for the specific application at hand. This type of system usually involves user specified design and/or performance criteria and close collaboration between the user and CANBERRA throughout the project – from inception to installation.

It is this class of system where active shielding (cosmic guards or Compton suppression) is often used. CANBERRA has a wealth of experience in building such systems and we welcome your inquiries should standard Low Background or Ultra Low-Background systems not satisfy your needs.

Read more in our Application Note entitled Ultra Low-Background Detector Systems for more information.

Typical Results

The following 50 000 second background spectra were taken with detectors having 100% relative efficiency. Spectrum A was taken without shielding. Spectrum B was taken with the detector in a standard cryostat (7500SL) operating in a standard 4 in. thick Lead Shield (747). Spectrum C was taken with the detector in an Ultra Low-Background Cryostat (7915-30 ULB) operating in a 15 cm (6 in.) thick ULB (Model 777) Lead Shield.

Comparative Background Counts are given below:

Without Shield Standard Cryostat and Shield ULB Cryostat and Shield
Total Counts/Sec (50-3000 keV) 142.3 3.35 1.84
Peaks Found 78 31 13

Of the thirteen peaks found in the spectrum from the ULB system only one, the 2.614 MeV peak from Tl -208 is a normal background line. All the rest are attributed to cosmic ray interaction in the shield and detector.

A listing of these peaks and their means of production is given below:

Energy (keV) Isotope/Origin Remarks
53.4 73mGe 72Ge (n,g)
66.7 73mGe 72Ge (n,g) (sum 13.3 & 53.4 keV)
139.7 75mGe 74Ge (n,g
198.4 71mGe 70Ge (n,g) (sum 174.9 & 23.4 keV
511 Positron ann. Doppler broadened
569.7 207Pb (n,n’) Originating from stable Pb
in shield
595.8 74Ge (n,n’) Broad assymetric, due to recoil summation
669.6 63Cu (n,n’)
691.0 72Ge (n,n’) Broad assymetric, due to recoil summation
803.1 206Pb (n,n’) Originating from stable Pb
in shield
834.0 72Ge (n,n’) Broad assymetric, due to recoil summation
962.1 63Cu (n,n’)
2614.5 208Tl Intensity about 0.1% of that of unshielded detector-believed to be shield penetration

Note: The fast and thermalised neutrons are of cosmic origin.

Ultra Low-Background Cryostats (ULB)

Description

CANBERRA has years of experience in building custom low-background detectors for low level gamma spectroscopy. The most important features of these custom detectors have been incorporated into standardized cryostat designs which can be produced quickly and economically and which produce predictable results. There are two basic Ultra Low-Background cryostat designs available, a vertical dipstick and a U-style integral. Both have the following design and construction features in common:

  1. Low background materials are used for detector chamber, holder, and internal hardware.
  2. Design offsets are used to allow the use of shielding materials between the detector element and hotter materials such as the preamplifier and adsorber (molecular sieves).
  3. Direct streaming paths for external (to shield) sources of radiation are eliminated.
  4. Materials having high cross-section for cosmic neutrons are avoided in construction.
  5. Designs do not compromise ease of use or long-term reliability.

Among the select materials used in CANBERRA ULB cryostats are the following:Ultra Low-Background Cryostats (ULB)

  • Aluminum – 99.999% pure with guaranteed thorium and uranium less than 1 ppb.
  • Copper – 99.99% pure (better than standard OFHC grade).
  • Stainless Steel – selected low Co-60 content.
  • Composite Carbon – Virtually zero background substitute for Be in low energy and wide range detectors.

Features

  • Low background materials
  • No-stream-path design
  • Offset preamplifier and adsorber
  • Standardized hardware
  • Uncompromised reliability

 

U-Style Cryostats

Description

CANBERRA U-Style cryostats have a vertically-oriented detector chamber located at the end of a horizontal arm extending from the side of the Dewar or cooler.

This configuration excludes the preamplifier and other hardware from the inner cavity of the lead shield and eliminates all line-of-sight streaming paths to the detector element. These features contribute significantly to the overall background reduction of the counting system.

The U-Style configuration has a lower center of gravity for the detector and shield as compared to a standard vertical configuration which may make it attractive for mobile applications as in trailer- or ISO container-based counting facilities. Additionally the U-style configuration allows installing the detector in systems where there is no room under the shield to place the Dewar or cooler.

 

The standard length of the horizontal arm is 12 in. (305 mm) measured from the flange of the preamplifier service body to the detector center line. This length makes the U-style cryostat compatible with both 4 in. (102 mm) and 6 in. (152 mm) thick CANBERRA lead shields.

The standard configuration comes with a radial O-ring seal. A metal face seal is available as an option on detectors with a 3.0 in. (76 mm) diameter endcaps only. Metal seals are more rugged and, in general, provide a longer life time of the detector vacuum.

End cap dimensions depend on detector size. The chart below shows the typical efficiency range vs. end-cap diameter. End cap lengths are also greater for larger detectors. Consult the factory if end-cap size is critical in your application.

Rel. Efficiency (%) Diameter in. (mm)
≤40 3.0 (76)
40-50 3.25 (83)
50-70 3.50 (89)
70-100 3.75 (95)
≥100 4.0 (102)


 

 

Model 767 Front Opening Split-Top Shield

Description

The 767 is a full-size and full-featured lead shield for use with germanium detectors having a vertical orientation. It has several unique design features and is built with a great deal of attention to fit and finish. The 767 features 10 cm (4 in.) lead thickness and is jacketed by a 9.5 mm (3/8 in.) steel outer housing. The graded liner consists of a tin layer of 1 mm (0.040 in.) thickness and a copper layer of 1.5 mm (0.062 in.) thickness. There is no exposed lead in the 767 with or without the doors closed. The inside dimensions are 28 cm (11 in.) diameter by 40.6 cm (16 in.) high.

The top doors of the 767 are linked so they open and close together regardless of which is actuated. The front door opens to the right on precision adjustable hinges and provides full shield access.

Top doors are linked – so they open and close together – Front door provides full-area access

A novel latch secures both the front and top doors and provides a means to lock the shield with a user-supplied padlock.

The shield table is equipped with leveling legs and with braces which allow the assembled shield to be moved with a simple pallet truck.

The 767 is finished outside with an attractive textured light gray epoxy paint. The copper interior has a brush grain finish with a clear polyurethane coating to retard tarnishing.

Features

  • Four-inch low background lead
  • Graded tin and copper liner
  • Fully clad – no exposed lead
  • Full area front door
  • Synchronized split top door
  • Lockable door latch
  • Textured epoxy finish

 

 

 

 

 

Model 747 and 747E Lead Shield

Description

The Model 747 CANBERRA Lead Shield is intended for use with Germanium detectors. It will prevent high background counts due to external sources, thus reducing counting times and improving the lower limit of detection. This shield is compact and easy to use with only 0.4?m2 (4?ft2) of floor space required. The shield may be set up so that the door opens right or left without need for clearance to the rear. A convenient lever-actuated door lift allows the door to be placed firmly on the shield to prevent direct path radiation from entering.

The 1 mm (0.040 in.) tin and 1.6 mm (0.062 in.) copper graded liner prevents interference by lead x rays. The exterior is attractively finished with light grey textured paint, the interior is coated with clear polyurethane to prevent oxidation and facilitate cleaning. The floor of the shield has a 12.1 cm (4.75?in.) diameter hole which will accommodate either flanged or slimline cryostats.

The 747E model is 10 cm (4 in.) shorter than the standard 747 and does not have a door lift mechanism.Model 747 and 747E Lead Shield

A number of options are available.Four-inch long, clamp-on cold finger extensions are available for most cryostats. Preamp hardware Option PHW (for CANBERRA Preamp) is also required to ensure that flanged cryostats fit within the 28 cm (11 in.) shield diameter. Adjustable foot pads provide a convenient means for leveling. Optional annular lead plugs are available to minimize the streaming path through the hole in the shield floor. A detector lift and taller table are available to accommodate installation of other cryostat types, such as the Cryo-Pulse?® 5 Plus, MAC’s and 7500SL-RDC. See option list on back for details.

Features

  • 4-inch thick low-background lead
  • Easy-to-use lever-actuated door
  • Compact – 2 foot by 2 foot floor space
  • Graded tin and copper liner
  • Adjustable foot pads

 

 

 

 

Model 777 Ultra Low-Background Shield

Description

The CANBERRA 777 is an ultra low-background lead shield for germanium gamma-ray detectors. It features 50% greater lead thickness than that of typical lead shields and is constructed from materials carefully selected for low background. The 777 is available in three versions which complement CANBERRA ultra low-background cryostats. The 777 (pictured right) can accommodate either a vertical dipstick slimline cryostat or a U-style cryostat. The 777A accommodates vertical dipstick cryostats only such as the 7500SL with a remote detector chamber (Model RDC-6). The 777B accommodates only U-style cryostats. All versions of the 777 are equipped with a swing-top door for sample chamber access and a door lift mechanism which allows the door to fit tightly against the shield body.

Background radiation from lead is dominated by 210Pb because other elements are chemically separated fairly effectively in the refining process. 210Pb decays with the emission of a 46.5 keV gamma ray. This gamma ray is generally absorbed by the tin-copper liner and may be below the energy range of the detector so it is of little concern. The 210Bi daughter of 210Pb, however, is of concern. It is an energetic beta emitter and bremsstrahlung from this beta gives rise to a continuum of background counts ranging up to 500 keV. For this reason, the 777 is constructed with layered bulk lead. The outer five inches is ordinary low-background lead while the innermost one inch is selected for 210Pb content of about 20 Bq/kg. This thickness of lead will stop the bremsstrahlung from the outer lead volume.

The 777 has a graded liner to stop the lead K-shell x rays in the energy range of 75-85 keV. Liner materials are low background tin with a thickness of 1 mm (0.040 in.) and high purity copper with a thickness of 1.5 mm (0.060 in.).

The 777 is equipped with a gas port for the introduction of gas (bottled air or nitrogen) to flush the shield interior and reduce background from radon and radon daughters. Boil-off nitrogen from the LN2 cryostat is a free source of gas but care must be taken to prevent liquid nitrogen from entering the shield and freezing the cryostat seals. An N2 purge kit is available from CANBERRA for most cryostat types.Model 777 Ultra Low-Background Shield

The 777A (see illustration in PDF) is supplied with a table which supports the shield above the LN2 Dewar. This shield has an opening in the floor and a split annular back shield which surrounds the cryostat RDC neck. The 777B (see illustration in PDF) is attached to a steel plate which normally sits on the floor. The 777B has a side port which accommodates the horizontal arm of a U-style cryostat and a rectangular plug which is withdrawn vertically to provide access to the port. An optional cryostat stand (Model 777-5) is available to support the cryostat.

Features

  • 15 cm (6 in.) lead thickness
  • Ultra low-background materials
  • Versions for vertical or U-style cryostats
  • Purge port for radon expulsion
  • Graded tin-copper liner

 

Model 737 Lead Shield

Description

The Model 737 Lead Shield is designed to accommodate U-style cryostats which have a vertical detector chamber located at the end of a horizontal arm extending from the side of the Dewar. This detector/shield arrangement excludes the preamplifier and other hardware from the shield volume and eliminates all line-of-sight streaming paths to the detector element. These factors can contribute significantly to overall background reduction in the counting system.Lead Shield Model 737 - U-Style

Unlike most shields of this type, the 737 is designed for ease of detector installation with a narrow, stepped plug providing access for the horizontal arm of the detector. This plug is removed vertically, thus minimal space is required between the shield and the Dewar with attendant reduction in floor space required for the system.

Like the Model 747 Shield, the 737 has a graded copper-tin liner and is jacketed by 3/8 in. steel finished in an attractive light grey textured paint which matches other CANBERRA products. The exclusive CANBERRA door lift mechanism allows the shield door to close lightly against the shield body, reducing the streaming path to virtually nothing.

 

Features

  • “No stream” design for U-style cryostat
  • Low center of gravity
  • Four-inch low background lead
  • Graded tin and copper liner
  • Easy detector installation

Lead Shield Model 707/707M – SlimlineModel 707 Lead Shield

Model 707 Lead Shield

  • Economical and light weight
  • For Slimline cryostats
  • Construction: steel jacket, lead bulk, Sn/Cu liner
  • Dimensions:
  • 152 mm (6 in.) inside diameter
  • 254 mm (10 in.) inside depth
  • 51 mm (2 in.) lead thickness
  • Table included: 61 x 61 cm (24 x 24 in.) x 68-76 cm (27-30 in.) high
  • Shipping weight – 250 kg (550 lb)

 

Model 707M Modular Lead ShieldModel 707M Modular Lead Shield

  • Modular construction
  • Maximum component weight- 227 kg (500 lb)
  • For Slimline cryostats
  • Construction: steel jacket, chevron lead rings, Sn/Cu liner
  • Dimensions:
  • 152 mm (6 in.) inside diameter
  • 254 mm (10 in.) inside depth
  • 102 mm (4 in.) shield thickness
  • Table included: 61 x 61 cm (24 x 24 in.) x 68-76 cm (27-30 in.) high
  • Shipping weight – 646 kg (1425 lb)

 

Ge Detector Accessories

Model 7413, 7413F Detector Tripod

  • For field measurements
  • Heavy duty construction
  • 7413 accommodates Slimline, MAC or Big MAC
  • 7413F accommodates Flanged, MAC or Big MAC
  • Detector element elevation (<30 cm to >120 cm)
  • Built-in level
  • Shipping weight – 9 kg (20 lb)

Model 757 Tungsten Shield/Collimator

  • High density (17 g/cc)
  • Compact
  • Requires special MAC
  • Specify collimator opening
  • Dimensions: 7.7 cm I.D. x 17.8 cm O.D. x 20.3 cm long (3.05 x 7.0 x 8.0 in.)
  • Shipping weight – 85 kg (187 lb)

Model 7415 Detector Lift

  • Accomodates MAC, Big MAC and Cryolectric II
  • Compatible with CANBERRA shields
  • Convenient and safe operation

Model 717 Portable Detector Shield

  • For MAC or Big MAC
  • 89 mm I.D. x 165 mm long (3.5 x 6.5 in.)
  • 25 mm (1.0 in.) thick lead
  • Brass lined-steel jacketed
  • Shipping weight – 34.5 kg (76 lb)

Model 7411 Detector Submarine

  • Accommodates single-port MAC
  • 6 m (20 ft) umbilical hose (longer available)
  • Ballast for fresh or salt water (specify)
  • Body Dimensions – 178 mm diameter x 591 mm long (7 x 23.25 in.)
  • Shipping weight – 20 kg (45 lb)

Model 7412 Annealing Kit

  • Fix radiation damage in situ
  • Includes:
  • Valve operator
  • Temperature controller (115 V ac only)
  • Heating tape or air heater (MAC)
  • Specify cryostat type
  • Shipping weight – 5 kg (11 lb)

Note: Controller subject to change with availability

Silicon Lithium Si(Li) detectors for charged particle spectroscopy

Description

Wide range of detector sizes:

  • In standard – Active areas from 200 mm2 up to 1600 mm2 thickness 5 mm.
  • Upon request – Larger active areas (like 2000 mm2 circular) or thicknesses up to 10 mm.

Gold front entrance window – Nominal 2000 angstrom equivalent Silicon.

Lithium back contact:

  • Typically for LEC/LER energy detectors – 300mm.
  • Typically for LTC/LTR transmission detectors – 50 mm.

Gold plated brass mounts:

  • Circular for LEC/LTC detectors.
  • Rectangular for LER/LTR detectors.
  • The standard dimensions are given below within the table.

In standard, with Microdot female connector located:Lithium Drifted Silicon Detectors

Axially (on the back of the detector) for LEC/LER detector type.

Radially (on the side of the detector) for LTC/LTR detector type.

Typical delivery 4-6 months for standard designs as given below within the table. All these detectors are built to order. Any special design on request.

Features

  • Designed for highly penetrating charged particles
  • Up to 3 MeV Betas, 30 MeV protons, 140 MeV Alphas. More if detectors are stacked (LTC/LTR)
  • Wide range of active areas
  • Both circular and rectangular mount shapes available
  • Telescope arrangements with minimized thin Li back contact (LTC/LTR)

 

Silicon Lithium Si(Li) Detectors for conversion electron Spectroscopy

Description

CANBERRA offers highly-reliable Silicon Lithium drifted detectors, cooled at cryogenic temperatures, for X-ray or conversion electron spectroscopy or beta decay exploration. Two configurations are available depending on the application. The ESLB is delivered with all components required for integration into an existing vacuum chamber. The ESLB-X comes with a complete cryostat and user friendly features to create a common vacuum between the cryostat and the experiment chamber.

ESLB Detector

ESLB detector consists of:

  • Lithium drifted Silicon diode
  • Aluminum mount including the diode and the first stage of the charge sensitive preamplifier (input FET, feedback network)
  • Two feedthrough connectors (multipin and high voltage connectors)
  • Charge sensitive preamplifier Model PSC761R with a 3.5 meter cable set

The detector is to be mounted on the cold finger of the cryostat (16 mm diameter). The remaining part of the resistive preamplifier is mounted outside the experiment chamber.

NOTE: The cryostat is not included in ESLB detectors; please use ESLB-X type if a complete cryostat is required.

ESLB-X Detector

An ESLB-X is a complete detector system consisting of:

  • Lithium drifted Silicon diode
  • Flanged dipstick cryostat with horizontal output as a standard – additional cryostat configurations are available as an option
  • Flange on the cap enables a vacuum connection on the customer’s vacuum chamber
  • The removable flange is equipped with a Be window for x-ray measurements
  • Charge-sensitive preamplifier with a cold input stage and resistive feed-back network – an alarm card drives the bias shut down signal in case of incorrect temperature
  • Set of cables (power supply – signal – high voltage)
  • VOP10 vacuum operator to enable easy access to the cryostat vacuumSilicium Lithium Si(Li) Detectors for conversion electron Spectroscopy

The ESLB-X detector is a ESLB detector embedded in a dedicated cryostat.

Features

  • Measurement of electrons from 20 keV to 3 MeV or x-rays up to 20 keV and even above with an increased detector thickness
  • Thin entrance window: gold front entrance window with nominal thikness of 2000 angstrom equivalent Silicon
  • Best performance through liquid nitrogen temperature operation
  • Storage at room temperature
  • Active thickness from 2 to 5 mm in standard and up to 10 mm on request
  • Beta resolution from 1.6 keV to 1.8 keV at 624 keV
  • Available with a cryostat as a turn key system (ESLB-X) or in kit form (ESLB)
  • Position sensitivity possible through segmentation (see ESLX-S & LTS sheet)

 

Silicium Lithium Si(Li) Detectors for conversion electron Spectroscopy

ESLB-X detector connected on a vacuum chamber. The ESLB-X is consisting of a portable slimline cryostat Big MAC type with a 7 liter Dewar.
By courtesy Dr. Wu – CIAE Beijing



Clover Detectors

Array of Four Coaxial Germanium Detectors for Largest Efficiency

Description

In the CLOVER detector assembly, the crystals are held on a minimized crystal holder to reduce the quantity of material surrounding the crystals and to improve peak to background ratio. With this principle CANBERRA is offering an optimized amount of HPGe material within the cap.

Moreover, crystals are packed very closely together to improve the add-back factor. The maximum gap between two adjacent crystals is ≤ 0.7 mm without any absorbent material along the whole crystal length that will absorb more than 1% of 20 keV gamma rays.

The four crystals are mounted in a common cryostat with a tapered or regular square shaped end cap.

Distance between end cap and crystals has been reduced to a very minimum to improve the solid angle and efficiency of any veto detector (BGO) which can surround the CLOVER cap. Also so called back catcher cryostats are available for given CLOVER types where a dedicated BGO detector can be installed at the rear of the cap.

A major advantage of a CLOVER detector consists of its high absorption efficiency: results are not only four times those obtained with a single crystal but, as crystals are mounted without any additional absorbing material, the full energy of a photon Compton scattered and absorbed in a second (or even a third) crystal can be determined. The full energy peak can be obtained by summing (“add-back”) the energies deposited in the N segments firing.

The “Add-back” efficiency is then superior to the sum of the four individual efficiencies.

Features

  • High photopeak efficiency in ‘add-back’ mode
  • High efficiency in 4π geometry (well type configuration)
  • Excellent energy resolution
  • Excellent timing response
  • Optional position information (segmentation can reduce Doppler broadening)
  • Reduced vulnerability to neutron damages
  • Good sensitivity to gamma ray polarization
  • Easy maintenance
  • Optional: low background materials, electrical cooling, extended energy range

Ge Clover Detectors

The first CLOVER detector was initially developed in France by CANBERRA in the frame of the EUROGAM collaboration. The original design consisted of a close arrangement of four n type germanium detectors like a 4-leaf clover. This configuration drastically improves the total system efficiency and compensates for the still limited relative efficiency of conventional n type crystals. Well over 200 CANBERRA CLOVER detectors are currently in operation worldwide. Although CLOVER detectors should be considered as specialty detectors or scientific instruments, they are highly reliable, allowing for routine maintenance to be performed by customers on-site. As is evidence: the first EUROBALL CLOVERS delivered in 1992 are still in operation.

Applications

  • Nuclear Physics
  • Polarization measurements
  • Health Physics (well type CLOVER)
  • Any application where the highest efficiency is required without compromises on energy or timing resolution

Encapsulated Detectors

Encapsulated Germanium Detectors for Gamma Measurements

Description

ENCAPSULATION TECHNIQUES

Mounting and operation of several detectors in a common vacuum with minimum spacing between consecutive elements makes a real challenge. Encapsulation techniques have been developed to minimize such problems. Placing each encapsulated detector into the vacuum in an individual aluminium cap makes it possible to separate the vacuum of each detector from the cryogenic vacuum shared by all detectors. Encapsulation drastically enhances the germanium detector reliability. This technology is key for many applications, particularly in space, and especially if associated with Ultra High Vacuum. Encapsulated germanium detectors may be easily handled by the users. They may be stored, exchanged or rearranged and be adapted to various applications with different types of cryostats.

A capsule may be regenerated many times and can be thermally annealed in an ordinary oven from neutron or proton radiation damages, without pumping. The life time of such a detector may be estimated to a minimum of seven years without service. But in reality it is much more: The first EUROBALL capsules were delivered in 1992 and are all still in operation. Encapsulated detectors hardness enables a wide application range, such as part of the payload of nacelles, space launchers, etc…

Compact arrays may be designed. The capsules manufactured for EUROBALL offer a typical wall thickness of 0.7 mm with a distance between cap and crystal of only 0.7 mm. These encapsulated detectors may be in contact with one another offering a 3 mm distance between consecutive crystals and a 1.4 mm total aluminium wall thickness.

For better follow-up of scientific progress, some segmented crystals have been encapsulated to offer high granularity, in addition to the previous advantages.

The detector granularity qualifies the number of independent cells constituting this detector. Such detectors allow a significant reduction or gamma ray broadening due to the Doppler effect.

Moreover, the use of internal and external contacts of the crystal provides information on the interactingposition:

  • Vertically and transversally, by analyzing signals induced by mirror charges.
  • Radially by making a pulse shape analysis.

Accurate localization of the interaction points allows not only reduction of the Doppler effect broadening, but also gamma ray tracking.

In addition to these benefits, the segmented detector encapsulation allows the design of complex cryostats, thus signal optimization which is of much interest for pulse shape analysis.

The feasibility of the germanium detector encapsulation was studied in the frame of a collaboration between CANBERRA, the Jülich research center and the University of Cologne in Germany.

Ge Encapsulated Detectors

Features

  • For compact construction of multi-element detectors for gamma ray applications
  • For very large efficiency and solid angle coverage for high sensitivity and low detection limit gamma ray spectroscopy even in harsh environments
  • Easy annealing in standard ovens, without pumping, in case of radiation damages
  • In situ annealing in space applications
  • Long detector life time
  • Large choice of shapes (pentagonal, hexagonal) for compact matrix assemblies
  • Essential for complex cryostat development, particularly with segmented detectors
  • Total reliability Ultra High Vacuum technology
  • Easy detector handling and exchange

Applications

Such a detector is easy-to-use, reliable and robust. So, it may be used in a large range of scientific and industrial applications such as:

  • Array of detectors for gamma spectroscopy (ex: MINIBALL, AGATA, GRETA nuclear physic experiments)
  • Research laboratory – Nuclear medicine
  • Environmental measurements
  • Industrial quality control
  • Homeland Security
  • Space experiments, thanks to its in situ re-generation capabilities after radiation damages (ex.: INTEGRAL, MARS ODYSSEY, SELENE,…)
  • Assistance to Engineers
    (ex: design of complex cryostats and /or multi elements detector electronic)

Ge Ruggedized Detectors

Description

Germanium detectors represent the best choice when high resolution gamma spectroscopy is required for accurate nuclide identification and quantification.

However, some potential problems can compromise the use of these technologies when the spectroscopy system is intended to be used in harsh environments such as:

  • Shock and vibration (transportation by trucks, separation of space launcher stages)
  • Industrial use in sites where liquid nitrogen is not available for detector refilling
  • Extreme climatic conditions (underwater operation, very high or low temperatures, etc.) in industrial or space environments

The combination of CANBERRA’s extensive experience with the evolution of new technologies (encapsulation, ultra high vacuum, waterproof design, shock absorption devices) make us the world leader in scientific and special applications involving HPGe detectors.

CANBERRA’s expertise allows our specialists to deliver outstanding and reliable detection instruments for the most demanding industries and research centers. Researchers have come to depend on these specialized instruments for their most critical experiments and studies.

Applications

  • Space
  • Environment
  • D&D
  • Industry

Ge Ruggedized Detectors
This mission consists of the equipment for a satellite in orbit around the Earth to study supernova, black holes, and other emitters of gamma bursts.

Features

  • Hardened design, shock and vibration resistant
  • Adapted cooling devices (electrical coolers)
  • Multiple references in space missions (Integral, Mars Orbiter, Selene…)
  • Encapsulation techniques allowing easy exchange of each individual detector when mounted in arrays
  • Dedicated shapes and materials for cryostats (hexagonal cutting, titanium light weight capsules, telescope mount, etc.)
  • Large choice of N-type detectors and associated annealing accessories for on-site repair after radiation damage
  • Ultra High Vacuum for the best reliability
  • Waterproof design for outdoor use
  • Easy to decontaminate

Segmented Coaxial Detectors

Description

CANBERRA’s Segmented Coaxial HPGe Detectors employ segmentation techniques available on planar detectors since the eighties (see Gutknecht et al NIM A288 (1990) 13-18) to provide high quality information signals from each detector cell (segment), while taking advantage of the total detection volume (as available with usual coaxial detectors.

The segmented coaxial Germanium offers, in addition to the characteristics of coaxial detectors (High efficiency and excellent resolution), the potential for excellent granularity.

Granularity of segmented coaxial detectors qualifies the number of independent cells constituting this detector. Longitudinal and transversal crystal segmentation in two or four drastically increases the granularity (up to 36 output channels are possible).

Such detectors allow an important reduction of gamma ray broadening due to Doppler effect.

Moreover, the use of internal and external contacts of the crystal (in case of detector segmentation) provides interaction position information:

  • Vertically and transversally by analyzing signals induced by mirror charges
  • Radially, by performing a pulse shape analysis

Accurate location of the interaction points allows not only reduction of the Doppler broadening, but also gamma ray tracking.

The external contact of a detector can be longitudinally or transversally segmented without dead zone generation. All segmentations are possible, on the front side (like a checker-board for example) and laterally (in one or two directions).

For a given n-segment detector, n+1 preamplifiers are used: one for each external segment plus one for the central contact. This design allows a better use of the full detection volume by AC coupling.

Segment separation is such that no cross-talk effect occurs between consecutive channels.

Ge Segmented Coaxial Detectors

Features

  • For gamma tracking, polarimetry, Doppler effect correction, β decay suppression
  • Longitudinal and transversal segmentation of the outer contact by photolithography (up to 36 segments), on various N type crystal geometries
  • No dead zone or absorbing material between segments
  • Monolithic detectors
  • No measurable crosstalk effects
  • Increased granularity of multi-detector systems
  • Localization of the interaction and gamma ray
  • Tracking capability through coincidence between internal core signal and segment contact signals

Applications

  • Nuclear physics:
    • Doppler effect correction
      (see also CLOVER
      detectors, Encapsulated
      detectors and Strip
      detectors)
    • Multiple site energy deposit
      and β decay suppression
    • Polarimetry
    • Tracking (see also
      Encapsulated and Strip
      detectors)
  • Compton cameras: Gamma ray sources location
  • Compton suppression

Segmented Planar Germanium EGPS series

Detectors for X and γ Ray Measurements

Description

CANBERRA series EGPS detectors are manufactured using a proprietary technology allowing design for the best strip germanium detectors available worldwide. CANBERRA uses photolithography techniques – usually employed in microelectronics – to germanium diodes. Thus, all kinds of segmentation patterns are possible (straight or curved strips, pixels, etc.) including double sided thin window segmentation. This reliable technology has been proven since the eighties.

Segmentation offers many benefits:

  • Suppression of dead layers between consecutive strips.
  • Thinnest pitch: down to 50 µm on single sided strips.
  • Excellent performances at high count rates (up to 1 million pulses per second).
  • 2-sided photolithography capability, with pitchs up to 200 µm.
  • Excellent FWHM resolution: typically <130 eV at 5.9 keV.
  • No measurable physical crosstalk.

The segmentation techniques fit with all crystal designs: circular, rectangular, etc. Diodes which are segmented by photolithography allow easier and more accurate 3D localization of interaction points than those obtained with segmented coaxial detectors. This is due to the electrical field characteristics within the detector. Several EGPS detectors may be associated in arrays or may be stacked in a single cryostat, thus offering smaller dead layers to increase of the angular covering (or high energy ray absorption depending on system configuration).

Various similar assemblies of that kind are used for Compton Cameras. EGPS detectors are cooled at liquid nitrogen temperature and may withstand many thermal cycles without any performance degradation. Such characteristics make CANBERRA EGPS series the best choice for X or gamma ray measurements in many applications such as Physics or Astrophysics experiments as well as non invasive detection or medical application.

Applications

  • Synchrotron (EXAFS, diffraction, medical beam lines)
  • Nuclear Physics (tracking)
  • Compton cameras (imaging)
  • Non destructive control
  • Radiography
  • Medical (BNCT, Angiography)

Ge Segmented Planar Detectors

Features

  • For high performance X and γ measurements in Physics, astrophysics, non-destructive control and medicine
  • Unique proprietary segmentation techniques developed and enhanced for over 15 years
  • Large range of shapes (pixels, strips) and segmentations (straight strips, circular, single or double sided)
  • Excellent energy resolution (<130 eV at 5.9 keV, depending on geometries
    and count rate)
  • Excellent performance at high count rates, with small as well as large detectors (up to 1 Mcps)
  • Accurate localization of the interaction points (1, 2 or 3D)
  • Thickness up to 20 mm
  • Crosstalk with physical pulses 1% maximum
  • Double sided segmentation capability, using CANBERRA thin window proprietary technology
  • Available with LN2 or electrical cooling

Telescope Detectors

Description

The purpose of a telescope arrangement of several planar and coaxial germanium detectors is to get wide energy range measurements with the best possible efficiency and background correction, like in cosmic gamma rays spectroscopy.

Stacks of planar and coaxial, pixel or strip segmented detectors can also be mounted or associated with Si(Li), PIPS® detectors to best focus on X-ray or charged particles by vetoing the main signal, and remove any unwanted background.

Such arrangement increases the detector resolving power by discriminating gamma rays from the measured background, and also by reducing Doppler broadening effects.

The absorption efficiency of such detector is very high due to the larger germanium volume crossed by photons or particles.

Moreover, special care has been taken to minimize dead areas within detector assemblies and stacks.

The thin contact technology is a main issue for charged particle detection.

Indeed, a stack of several crystals is a very interesting tool for high energy charged particles measurements.

Stacks of planar and coaxial detectors and assemblies of stack in arrays in common cryostat are possible.

CANBERRA can offer a dedicated cryostat with special high cooling power LN2 Dewars developed for array detectors (Clover detectors). LN2 free solutions are possible as well with the latest electrical cooling technology. This is now a very mature cooling solution in case LN2 has to be banned because of safety or security regulations; any room constraints (industrial applications) or accessibility (space applications).

Applications

  • Waste barrel monitoring or whole body counting systems: Both applications need highest efficiency, wide energy range and lowest MDAs
  • Space spectroscopy: background reduction by multiple site method (ß decay suppression)
  • Compton cameras: telescope of double sided strip detectors (DSSDs)
  • Nuclear physics: Doppler broadening correction by incidence angle measurements (segmented planar detector stack)
  • High energy measurements of gamma rays with best achievable efficiency
  • Background reduction by vetoing of charge particles
  • High energy proton spectroscopy

Telescope Detectors

Features

  • Multi-arrangement of planar, or planar and coaxial detectors (segmented or not), HPGe or Si(Li) or PIPS®
  • Extended gamma-ray energy range or charged particle discrimination
  • Background suppression by using coincidence timing between detectors
  • No measurable crosstalk effects between channels
  • Minimized dead areas between detector layers
  • Stable thin window proprietary technology not affected by heat cycling or neutron annealings

ESLX-S & LTS Detectors

Segmented Planar Silicon-Lithium Detectors for X-ray and Charged Particle Measurements

Description

The Segmented Si(Li) detectors (ESLX-S and LTS) are manufactured using a proprietary technology allowing design of the unique segmented silicon detectors available worldwide.

CANBERRA has applied the photolithography proven techniques – usually employed in microelectronics – to Si(Li) diodes. Thus, all kinds of segmentation patterns are possible (straight or curved strips, pixels, etc.).

CANBERRA also offers a proprietary double sided thin window segmentation. This enables to build telescope systems consisting of several layers of Si(Li) detectors.

Segmentation offers many advantages:

  • High efficiency through best area coverage: Suppression of dead zones between consecutive strips.
  • Best granularity: Small pitch down to 2 mm.
  • Fastest response: Good behavior at high count rates (up to 1 million pulses per second) due to fast preamplifiers without any compromise on signal to noise ratio.
  • 2-sided photolithography capability, with pitches down to 2 mm.
  • Excellent FWHM resolution: typically 150 eV at 5.9 keV on cooled ESLX-S devices for X-ray measurements.
  • No measurable crosstalk.

Segmentation techniques fit with all crystal designs: circular, rectangular, etc.

Several Si(Li) detectors may be associated in arrays to increase angular coverage or may be stacked.

ESLX-S detectors in a unique cryostat, offer high energy X-ray absorption or imaging capabilities (gamma cameras).

ESLX-S detectors are cooled at liquid nitrogen temperature and withstand many thermal cycles.

Such characteristics make ESLX-S series the best choice for X-ray measurements in many applications such as physics experiments as well as non invasive detection.

LTS detectors are operated at room temperature or are peltier cooled for improved performances compared to those at room temperature.

ESLX-S & LTS Detectors

Features

  • ESLX-S: For high performance X-ray measurements in Physics (PIXE, synchrotrons…), Non Destructive Assay and Medicine
  • LTS: For high performance charged particles measurements in Physics (Conversion Electrons, Mini-Orange) and RMS (air monitoring)
  • CANBERRA mature proprietary segmentation technique
  • Wide range of shapes (pixels, strips) and segmentations (straight strips, circular, single or double sided)
  • Excellent energy resolution (150 eV at 5.9 keV for ESLX-S, depending on geometries)
  • Good behavior at high count rates
  • Thickness up to 10 mm
  • Minimum pitch 2 mm
  • Crosstalk ≤1%
  • Double sided segmentation capability, using CANBERRA thin window proprietary technology
  • For ESLX-S: LN2, cryogenerator or Peltier cooling
  • LTS are used at room temperature but can be cooled by Peltier effect in case improved performances are required

Applications

  • PIXE (microprobes)
  • Synchrotron (EXAFS, medical beam lines)
  • Nuclear Physics
  • Non destructive control
  • Radiography
  • Imaging (gamma cameras)
  • Typically for LTS: CAM (Continuous Air Monitoring) on beta particles


Scintillation Detectors Model 802

DescriptionScintillation Detectors Model 802

The Model 802 Scintillation Detector is a hermetically sealed assembly which includes a high resolution NaI(Tl) crystal, a photomultiplier tube, an internal magnetic/ light shield, an aluminum housing, and a 14-pin connector.

The 802 series of NaI(Tl) detectors provides high efficiency and uniform response on both the cylindrical and well configurations. These detectors have a proven record of long term reliability and stability.

Any Model 802 assembly plugs directly into the Model 2007 Tube Base which provides power for the photomultiplier tube. Alternatively, the Model 802 can plug into the Model 2007P combination tube base and preamplifier.

Many crystal sizes are available, with the most common sizes listed below. Consult the factory for information on other sizes.

 

Features

  • Guaranteed resolution
  • Low mass housing
  • Less than 0.5 ppm of potassium
  • Mu metal magnetic light shield

NAID NaI Detector

Description

The NAID is a NaI detector specially designed for use in the measurement of uranium enrichment, and is used by the International Atomic Energy Agency in Vienna, Austria, and other safeguards related organizations. This detector is designed to be used in a variety of environments and, when combined with the CANBERRA IMCA uranium enrichment analyzer, permits automation of the energy calibration and temperature compensation. This detector employs a 241Am seed and thermistor mounted together with the 5.1 cm diameter by 1.3 cm thick NaI crystal. The americium acts as a pulser that produces a photopeak at the gamma-equivalent-energy (GEE) of approximately 3.0 MeV which is high enough to prevent interference with the 185.7 keV gamma peak produced from the decay of 235U. The seed and thermistor combination allows for automation of the energy calibration and compensation for differences in temperature drifts between the 185.7 keV peak and the 3.0 MeV GEE peak. The entire detector assembly is located within an integral, sealed housing.

The NAID is the detector of choice for situations demanding robust performance. The rugged housing of the NAID protects and secures the fragile internal components against minor impacts, and is splash resistant. The heavy duty LEMO single piece connector greatly simplifies setup with no individual BNC connectors to contend with and is extremely strong. It snaps securely into the detector and is easily disconnected with gloved hands.

Every NaI detector has a unique gain drift as a function of temperature. Each NAID may be optionally characterized by placing the detector in a temperature chamber and plotting the drift in the 185.7 keV and 3.0 MeV GEE peaks and thermistor value over a temperature ranges of –10 to +50 °C. This data is provided to the IMCA software in the form of a table. Stability of the system is 0.5% from –10 to +50 °C. This technique eliminates the individual temperature matching of NAIDs to analyzers, and allows any detector to be used with any IMCA.NAID NaI Detector

CANBERRA offers the NAID with LEMO connector, cable, and temperature characterization service that enables operation with full automatic stabilization and energy calibration of the IMCA in PMCN mode. See IMCA literature for details.

Features

  • Americium seed with thermistor provides total automated energy calibration capability
  • Ruggedized, housing integrates all detector components, including preamplifier
  • Splash resistant design
  • Extended temperature operation range: –10 to +50 °C
  • Rugged, integrated connector simplifies detector connections for error free operation

NAIS-2×2 – NaI(Tl) LED Temperature-Stabilized Scintillation Detector

Description

Model NAIS-2×2 Sodium Iodide Scintillation Detector is a high-efficiency scintillation detector featuring a 2 x 2 in. NaI(Tl) crystal in an aluminum housing, including a photomultiplier tube, an internal magnetic/light shield, a high-voltage power supply (HVPS), stabilization electronics, preamplifier, and an 8-pin CANBERRA proprietary connector. NaI(Tl) detectors have a proven record of long term reliability and stability.

The NAIS-2×2 NaI(Tl) detector is LED temperature-stabilized*, eliminating the peak-shift problems inherent to scintillation detectors. This makes the NAIS-2×2 suitable for use in non-air-conditioned rooms as well as in field applications. The LED temperature-stabilized probes continuously monitors and adjusts the gain of the detector automatically to ensure consistent performance throughout the entire temperature range. The consistent performance allows users to perform nuclear identifications under all conditions and environments that are typically encountered indoor and outdoor, while maintaining the highest confidence in the results obtained by the instrument.

The detector comes with a generic mathematical efficiency characterization known from CANBERRA’s line of high-resolution HPGe detectors. Quantitative measurements can be performed without the use of calibration sources using CANBERRA’s mathematical efficiency calibration software ISOCS™/LabSOCS™.NAIS-2x2 - NaI(Tl) LED Temperature-Stabilized Scintillation Detector

The housing is of an all-metal construction and features a robust locking mechanism for increased reliability. The cam lock provides a positive mechanical connection to the tube base instead of relying on the electrical pin friction only.

In combination with the Osprey – CANBERRA’s all-in-one HVPS, preamplifier, and digital MCA – the NAIS-2×2 becomes part of a high-performance scintillation spectrometry system suited for a wide range of applications – laboratory (with Model 727 shield), radiation monitoring networks, field use, etc.

 

Features

  • Patented LED temperature stabilization
  • Stable to within ±2% over the temperature range of -20 °C to 50 °C.
  • Generic efficiency characterization
  • Compatible with CANBERRA Osprey™ digital tube-base MCA only
  • Cam lock for increased ruggedness
  • All-metal housing with a magnetic/light shield

NAIS-3x5x16 – NaI(Tl) LED Temperature-Stabilized* Scintillation Detector

Description

Model NAIS-3x5x16 Sodium Iodide Scintillation Detector is a high-efficiency scintillation detector featuring a 3x5x16 in. NaI(Tl) crystal in a stainless steel housing, including a photomultiplier tube, an internal magnetic/light shield, a high-voltage power supply (HVPS), stabilization electronics, and preamplifier. NaI(Tl) detectors have a proven record of long term reliability but have peak-shifting issues in changing temperatures.

The NAIS-3x5x16 NaI(Tl) detector is LED temperature-stabilized*, eliminating these peak-shift problems caused by fluctuations in ambient temperature. This makes the NAIS-3x5x16 suitable for use in non-air-conditioned rooms as well as in field applications. The in-built LED temperature stabilization continuously monitors and adjusts the gain of the detector automatically to ensure consistent performance throughout the entire temperature range. This allows users to perform nuclide identification under all conditions and environments (both indoor and outdoor), while maintaining the highest confidence in the results obtained by the instrument.NAIS-3x5x16 – NaI(Tl) LED Temperature-Stabilized* Scintillation Detector

The housing is of stainless steel construction. The NAIS-3x5x16 gain stabilizer is optimized for digital signal processor shaping of 1 µs rise time and 1 µs flat top, which is the default setting of the Osprey digital tube base MCA.

 

Features

  • Patented LED temperature stabilization*
  • Stable to within ±2% (typical) over the temperature range of -20 °C to 50 °C.
  • Compatible with CANBERRA Osprey™ digital tube-base MCA and Lynx® MCA
  • Compatible with DSP-based CANBERRA InVivo Counters (FASTSCAN, ACCUSCAN Bed, Scanning WBC/Actinide Lung Counters)
  • All-metal housing with a magnetic/light shield

*US Patent 7,005,646 B1 and 7,049,598 B1

LABR-1.5×1.5 – LaBr3(Ce) Scintillation Detector

Description

Model LABR-1.5×1.5 Lanthanum Bromide Scintillation Detector is a medium-resolution scintillation detector featuring a 1.5 x 1.5 in. LaBr3(Ce) crystal in a hermetically sealed aluminum housing, including a photomultiplier tube, an internal magnetic/light shield, and a 14-pin connector.

The LABR-1.5×1.5 LaBr3(Ce) detector is completely compatible with the signal processing electronics normally used with NaI(Tl) scintillation detectors. However, the performance of the LABR-1.5×1.5 is superior to that of NaI(Tl) detectors. No adapters are required for direct connection of tube base preamplifiers or MCAs to the 14-pin PMT base. The better resolution, efficiency and relatively short decay time (16 ns) allow these detectors to be used with more complex spectra than scintillation detectors based on NaI(Tl) as well as in other applications previously thought to be too demanding for any scintillation detector. On the other hand, the LaBr3(Ce) detectors are not well-suited for low-level application due to their relatively high intrinsic background from the decay of 138La.LABR-1.5x1.5 - LaBr3(Ce) Scintillation Detector

Model LABR-1.5×1.5 plugs directly into the Model 2007 Tube Base as well as into Model 2007P combination tube base and preamplifier. Model 2007/2007P connect to an MCA or other standard signal processing electronics.

However, the most powerful combination is to use the LABR-1.5×1.5 with the Osprey™ – CANBERRA’s all-in-one HVPS, preamplifier, and digital MCA.

Features

  • Approximately half the FWHM of comparable sized NaI(Tl) detectors above 350 keV
  • Higher efficiency than similarly sized NaI(Tl) detectors – 1.2-1.65 times above 350 keV
  • Room temperature operation and same form factor as NaI(Tl) detectors
  • Directly compatible with traditional scintillation detector electronics and multi-channel analyzers
  • All-metal housing with a magnetic/light shield

Lead Shield Model 727/727R for NaI detectors

Description

The Model 727 Universal Shield accommodates NaI(Tl) detectors up to 3 in. x 3 in. in size providing two inches of lead shielding around the detector. The shield is lined with 0.6 cm (0.25 in.) thick copper or brass to minimize interference from lead x-rays and is jacketed with 0.6 cm (0.25 in.) of steel and finished with an attractive and durable textured epoxy paint.Lead Shield Model 727/727R for NaI detectors

The 727 can be used with either standard or well-type detectors and will accommodate samples up to 8.9 cm (3.5 in.) diameter and 7.6 cm (3 in.) long. Access to the sample chamber is available by way of the stepped plug which affords a 2.5 cm (1 in.) diameter opening, or by way of the swivel top which opens almost effortlessly to either right or left, providing the full-area opening necessary for large samples.

Adapter kits are available for a variety of detector sizes. The optional sample holder provides for sample-detector spacing of 0 to 3 inches in 0.25 inch increments.

The Model 727R is like the Model 727 except it has an enlarged sample space to accommodate 10 cm (4 in.) diameter charcoal canisters. The enlarged sample space is 11.4 cm diameter by 3.8 cm deep (4.5 by 1.5 in.).

Features

  • Low background lead – 5 cm thick
  • Accommodates large samples
  • For standard or well detectors
  • Full 4π shielding
 

NaI Detector Accessories

Model 7419 Shield/CollimatorModel 7419 Shield/Collimator

  • All attitude
  • Compact – swivel legs and folding handle
  • Removable collimator – 44 mm (1.75 in.)
  • Removable tin filter – 1 mm thick (0.040 in.)
  • Lead shielding – 8 mm wall x 122 mm long (0.32 x 4.8 in.)
    7419BS – 8 mm wall x 76 mm long (0.32 x 3.0 in.)
  • Shipping weight – 6.5 kg (14 lb)
  • Five models – specify when ordering
    • 7419A for 802-2 x .5
    • 7419B for NAID
    • 7419BS for NAID (with detachable legs)
    • 7419C for 802-2 x 2
    • 7419E for IPROS-2

 

Passivated Implanted Planar Silicon (PIPS®) detector

CANBERRA Semiconductor is dedicated to the development and manufacture of silicon detectors for the research, government and industrial communities. Focused on continuous improvement and innovation, we are committed to providing customers with reliable, high performance devices that meet or exceed their expectations.

CANBERRA designs and builds

silicon detectors

to your requirements.

PIPS® Detectors By Applications

Geiger Mueller (GM) Detectors

Description

CANBERRA Geiger Mueller Detectors have been carefully researched and developed to provide a rugged, reliable, long-lasting means of monitoring nuclear radiation levels. These detectors offer guaranteed advantages, including manufacturing consistency, product reliability and competitive pricing. Many of our tube types, including those approved for the military Quality Product List (QPL), are manufactured and tested to withstand rigorous shock and vibration per military standards.

GM Pancake Detectors (Halogen Quenched)

Description

Pancake detectors are widely used in nuclear probes and instruments for detecting and measuring alpha, beta or gamma surface contamination of clothes, small objects, benches, floors, roads, etc. Such halogen-quenched Geiger Mueller detectors are cost-effective, have an unmatched quality/cost ratio, are easy to use and are very reliable. Their ultra-thin mica window allows for an efficient detection of alpha, low energy beta and gamma radiation.

Adherence to stringent design parameters, manufacturing procedures and quality assurance provisions of CANBERRA products has successfully fulfilled commercial and military exacting standards. Our military approved detectors used by military customers worldwide, are able to withstand rigorous shock and vibration testing.GM Pancake Detectors

Our 2000-series of GM detectors provides a direct-replacement to most widely used competitive detectors. These can be incorporated into various radiation monitors and dosimeters. Our GM pancake detectors range in diameter from 33.5 mm (1.32 in.) to 53.6 mm (2.11 in.) and are also offered in Low Hysteresis and High Altitude models. These are used in CANBERRA’s own line of products as well as products from various companies. Please contact us should you wish to discuss specific requirements or references.

Features

  • 1.8 to 2.2 mg/cm2 Ultra Thin Mica Window
  • 28 or 45 mm effective diameter
  • High alpha, beta and gamma efficiency
  • Cost effective, easy to use and very reliable with unmatched quality/cost ratio
Characteristics Detector Type (for α, β, γ applications)
T2000/8767**
T2000/900 LH
T2000/900 HA
T2000/500
T2000/500 LH
T2000/500 HA
T2006/900
T2006/900 LH
T2006/500
T2006/500 LH
T2011/900 T2011/500
Applications SBM-2D, SBS BP-100 BP-77 MCB2, SABG-15
Sensitivity*
137Cs cpm at 1 mR/h*
3500 3500 3500 3500 1500 1500
Window Area Density (mg/cm2) 1.8- 2.0 1.8- 2.0 1.8- 2.2 1.8- 2.2 1.8-2.0 1.8-2.0
Window Effective Diameter (mm, in.) 44.5, 1.75 44.5, 1.75 44.5, 1.75 44.5, 1.75 28.4, 1.12 28.4, 1.12
Recommended Operating Voltage (HV+) 900 500 900 500 900 500
Plateau Length Volts min. 850-1000 450-600 850-1000 450-600 850-1000 450-600
Plateau Slope (%100 V max.) 10 10 10 10 5 5
Dead Time (µs max.) 50 50 50 50 40 40
Background (cpm)
Shielding 2″ Pb + 1/8″ Al
30 max. 30 max. 30 max. 30 max. 18 max. 18 max.
Resistor Ra (MΩ) 3.3 3.3 3.3 3.3 3.3 3.3
Resistor R1 (MΩ) 1.0 1.0 1.0 1.0 1.0 1.0
Operating Temp. (°C) –20 to +55 –20 to +55 –20 to +55 –20 to +55 –20 to +55 –20 to +55
Cathode Material Cr/Fe Cr/Fe Cr/Fe Cr/Fe Cr/Fe Cr/Fe
Max. Overall Length including Pins (mm, in.) Pancake Detectors
LH = Low Hysteresis Model
HA = High Altitude Model
Pancake Detectors Pancake Detectors
OPTIONS:
FL = Flying Leads
C = Push-on Anode Clip
Max. Overall Diameter (mm, in.)
Window Recess (mm, in.) 1.6, 0.062 1.6, 0.062 1.6, 0.062 1.6, 0.062 1.3, 0.05 1.3, 0.05
* At recommended operating voltage
** The only Mil. Spec. Pancake is the “jan 8767”

Description

Our GM End Window detectors provides direct-replacement to most widely used competitive detectors. These can be incorporated into various radiation monitors and dosimeters. Our GM End Window detectors are offered in two diameters: either 19.8 mm (0.78 in.) or 28.4 mm (1.12 in.). These are used in CANBERRA’s own line of products as well as products from various companies. Please contact us should you wish to discuss specific requirements or references.GM End Window Detectors

Features

  • 1.8 to 2.2 mg/cm2 Ultra Thin Mica Window
  • 19.8 or 28.4 mm effective diameter
  • High alpha, beta and gamma efficiency
  • Cost effective, easy to use and very reliable with unmatched quality/cost ratio
Mica End Window (for α, β, γ Applications)
Mil. Version 2121 M Window 2.8–3.4 mg/cm2 Probe contains 2131 tube. Available with BNC.
Characteristics T2121 TP2121S TP2131 TP2131/4P
Application α, β, γ α, β, γ α, β, γ α, β, γ
Sensitivity*
137Cs cpm at 1 mR/h*
1700 1700 2400 2400
Window Area Density (mg/cm2) 1.8 – 2.2 1.8 – 2.2 1.8 – 2.0 1.8 – 2.0
Window Effective Diameter (mm, in.) 19.8, 0.78 19.8, 0.78 28.4, 1.12 28.4, 1.12
Recommended Operating Voltage (HV+) 500 500 900 900
Plateau Length Volts min. 450 – 700 850 – 1000 850 – 1000 850 – 1000
Plateau Slope (%100 V max.) 5 5 10 10
Dead Time (µs max.) 100 100 150 150
Background (cpm)
Shielding 2″ Pb + 1/8″ Al
30 max. 30 max. 40 max. 40 max.
Resistor Ra (MΩ) 3.3 1.0 1.0 1.0
Resistor R1 (MΩ) 1.0 1.0 1.0 1.0
Operating Temp. (°C) –40 to +75 –40 to +75 –40 to +75 –40 to +75
Cathode Material Cr/Fe Cr/Fe Cr/Fe Cr/Fe
Max. Overall Length including Pins (mm, in.) 51.0, 2.0 94, 3.7 124, 4.85 115, 54
Max. Overall Diameter (mm, in.) 25.4, 1.0 82, 3.22 35 – 1.38 35, 1.38
Window Recess (mm, in.) 1.6, 0.062 1.6, 0.062 1.6, 0.062 1.3, 0.05
* At recommended operating voltage.
Detector Type Applications
T2121M Military
TP2131 Radiation monitors with BNC connection
T2131-4P Radiation monitors with 4 pin JEDEC connection
Related Industry Models
CANBERRA Centronics LND Saint Gobain
Mica End
Window Detectors
T2121 ZP1410 7224 N/A
T2131 N/A 723 N210-1
TP2131 N/A 7232 N210/BNC
Related Industry Models
CANBERRA LND Saint Gobain
Pancake T200/8767 7311 N1002/8767
T2006/900 73118 N1006
T2011/500 7231 N1004

Description

Our gamma and gamma/beta detectors are designed to handle harsh environments, and have a very long operating lifetime in excess of 5 x 1010 counts. These are offered in a wide range of lengths (51 mm to 351 mm) and diameters of (15.2 mm to 19.3 mm) and can be used as direct replacements for competitive detectors. These are widely used in radiological surveys and monitoring equipment as well as industrial and laboratory applications. Please contact us should you wish to discuss specific requirements or references.

Our beta sensitive detectors have a wall thickness of 40-60 mg/cm2, (average 0.002″). They are used in many reactor safety monitoring systems and have proved to be very reliable even when used in semi-corrosive conditions at elevated temperatures.

Features

  • This group of detectors covers a wide range of sensitivity to closely match our customer applications
  • Well designed and proven construction ensures a long and reliable operating life
  • Ideal for industrial control, area and site monitors, and reactor cooling system monitoring
  • Cost effective, easy to use and very reliable with unmatched quality/cost ratio
GM Gamma & Gamma/Beta Sensitive Detectors
Thin Wall Detectors (for β, γ Applications)
Flying lead connections available for these models.
Indicated by “-FL” suffix on order
Characteristics T2200 T2202 T2211
Application β, γ β, γ β, γ
Sensitivity*
137Cs cpm at 1 mR/h*
5275 2900 1550
Window Area Density (mg/cm2) N/A N/A N/A
Window Effective Diameter (mm, in.) N/A N/A N/A
Recommended Operating Voltage (HV+) 900 900 900
Plateau Length Volts min. 850-1000 850-1000 850-1000
Plateau Slope (%100 V max.) 8 8 8
Dead Time (µs max.) 100 75 150
Background (cpm)***
Shielding 2″ Pb + 1/8″ Al
60 max. 30 max. 20 max.
Test Circuit Figure 1 Figure 1 Figure 1
Resistor Ra (MΩ) 1.0 1.0 1.0
Resistor R1 (MΩ) 1.0 1.0 1.0
Operating Temp. (°C) -40 to +75** -40 to +75** -40 to +75
Cathode Material Cr/Fe Cr/Fe Cr/Fe
Cathode Wall 40-60 mg/cm2 40-60 mg/cm2 40-60 mg/cm2
Max. Length including Pins (mm, in.) 276, 10.9 148, 5.83 110, 4.31
Max. Overall Diameter (mm, in.) 16.0, 0.63 16.0, 0.63 19.3, 0.75
Window Recess (mm, in.) N/A N/A N/A
* An exposure of 115.07 mR in air equates to 1.0 mGy.
** High temperature version available for 150 °C operation.
*** At recommended operating voltage.
Thick Wall Detectors (for γ Applications)
Flying lead connections available for these models.
Indicated by “-FL” suffix on order
Characteristics T2306 T2311 T2314 T2316 T2350
Application γ γ γ γ γ
Sensitivity*
137Cs cpm at 1 mR/h*
950 1850 3050 3950 8150
Window Area Density (mg/cm2) N/A N/A N/A N/A N/A
Window Effective Diameter (mm, in.) N/A N/A N/A N/A N/A
Recommended Operating Voltage (HV+) 900 900 900 900 900
Plateau Length Volts min. 850-950 850-950 850-1000 850-1000 850-1000
Plateau Slope (%100 V max.) 8 8 6 6 10
Dead Time (µs max.) 100 100 100 100 120
Background (cpm)***
Shielding 2″ Pb + 1/8″ Al
12 max. 30 max. 47 max. 60 max. 100 max.
Test Circuit Figure 1 Figure 1 Figure 1 Figure 1 Figure 1
Resistor Ra (MΩ) 3.3 3.3 3.3 3.3 3.3
Resistor R1 (MΩ) 1.0 1.0 1.0 1.0 1.0
Operating Temp. (°C) -40 to +75 -40 to +75 -40 to +75 -40 to +75 -40 to +75
Cathode Material Cr/Fe Cr/Fe Cr/Fe Cr/Fe Cr/Fe
Cathode Wall 0.25, 0.010 0.25, 0.010 0.25, 0.010 0.25, 0.010 0.25, 0.010
Max. Length including Pins (mm, in.) 86, 3.4 119, 4.7 165, 6.5 197, 7.75 351, 13.82
Max. Overall Diameter (mm, in.) 16.0, 0.63 16.0, 0.63 16.0, 0.63 16.0, 0.63 19.3, 0.76
Window Recess (mm, in.) N/A N/A N/A N/A N/A
* An exposure of 115.07 mR in air equates to 1.0 mGy.
** High temperature version available for 150 °C operation.
*** At recommended operating voltage.
Detector Type Applications
T2200 Beta Monitor Industrial Safety System
T2202 Beta Monitor Industrial Safety System
T2211 Beta Monitor Industrial Safety System
T2306 Gamma Monitor, Portable Monitoring System
T2311 Gamma Monitor, Portable Monitoring System
T2314 Gamma Monitor, Portable Monitoring System, Industrial Control
T2316 Gamma Monitor, Portable Monitoring System, Industrial Control
T2350 Area and site Monitoring
Related Industry Models
CANBERRA Centronics LND Saint Gobain
Thin Wall Detectors T2200 ZP1860 719 N107/3P
T2202 ZP1850 721 N106/3P
T2211 N/A 725 N112
Thick Wall Detectors T2316 N/A 743 N310/3P
T2350 N/A 78017 N/A

GM Miniature Detectors

Description

The range of our Miniature GM Detectors offers a wide choice of sensitivity levels available to meet our customer requirements. From low level background environments to levels up to 1000 R/hr. gives our customer the opportunity to select the ideal detector for their application.

Robust construction and the ability to withstand excessive shock and vibration as required for military applications, makes these detectors an ideal choice for small hand held pocket dosimeters and small portable health physics monitors. Please contact us should you wish to discuss specific requirements or references.GM Miniature Detectors

Features

  • Rugged construction designed to tolerate harsh operating conditions
  • Halogen quenched to maximize operating life
  • A wide range of sensitivities to suit customer needs
  • Ideal for small monitoring equipment and personal health physics applications
  • Low cost and very reliable over long periods of time
Gamma Sensitive Miniature Detectors
Anode pin connector and cathode strap are supplied. Stated wall thickness includes glass envelope and cathode wall where appropriate. To achieve maximum linear count rate, always solder Ra directly to the supplied anode pin connector, or to the anode flying lead.
Characteristics T2411M T2416A T2417A T2420M T2422
Sensitivity***
137Cs cpm at 1 mR/h*
84 420 450 4.2 0.66
Window Area Density (mg/cm2) N/A N/A N/A N/A N/A
Window Effective Diameter (mm, in.) N/A N/A N/A N/A N/A
Recommended Operating Voltage (HV+) 575 575 575 500 460
Plateau Length Volts min. 500–650 500–650 500-650 450–550 450–550
Plateau Slope (%100 V max.) 15 8 8 35 40 max.
Dead Time (µs max.) 15 45 45 20 10
Background (cpm)
Shielding 2″ Pb + 1/8″ Al
2 max. 12 max. 5 max. 6 typ. 0.6 typ.
Test Circuit Figure 2 Figure 2 Figure 2 Figure 2 Figure 2
Resistor Ra (MΩ) 2.2 4.7 4.7 4.7 4.7
Operating Temp. (°C) –40 to +75 –40 to +75 –40 to +75 –51 to +71 –20 to +60
Cathode Material Cr/Fe Cr/Fe Cr/Fe Cr/Fe Cr/Fe
Cathode Wall 80–100
mg/cm2
64–80
mg/cm2
64–80
mg/cm2
360–400
mg/cm2
360–400
mg/cm2
Max. Overall Length including Pins (mm, in.) 37, 1.46 51, 2.0 46, 1.82 20, 0.8 20, 0.8
Max. Overall Diameter (mm, in.) 6.2, 0.244 10, 0.4 9.20, 0.36 7, 0.28 7, 0.28
Window Recess (mm, in.) N/A N/A N/A N/A N/A
* An exposure of 115.07 mR in air equates to 1.0 mGy.
*** At recommended operating voltage.
The T2422 detector is equivalent to the 3G10.
Gamma Sensitive Miniature Detectors
L – Max. Length without Leads
D – Max. Overall Diameter
Characteristics 3G70/
EM14752
3G70
4G60M/
EM14754
4G60M
4G2500/
EM14749
4G2500
3G6500/
EM14748
3G6500
Sensitivity***
137Cs cpm at 1 mR/h*
4.2 4.2 150 270
Window Area Density (mg/cm2) N/A N/A N/A N/A
Window Effective Diameter (mm, in.) N/A N/A N/A N/A
Recommended Operating Voltage (HV+) 460 500 550 460
Plateau Length Volts min. 420–500 450–550 500–600 420–500
Plateau Slope (%100 V max.) 30 30 25 25
Dead Time (µs max.) 25 25 35 50
Background (cpm)
Shielding 2″ Pb + 1/8″ Al
0.6 max. 0.6 max. 6 max. 10 max.
Test Circuit Figure 2 Figure 2 Figure 2 Figure 2
Resistor Ra (MΩ) 4.7 4.7 4.7 4.7
Operating Temp. (°C) –20 to +60 –20 to +60 –20 to +60 –20 to +60
Cathode Material Cr/Fe Cr/Fe Cr/Fe Cr/Fe
Cathode Wall 360
mg/cm2
360
mg/cm2
260
mg/cm2
280
mg/cm2
Max. Overall Length including Pins (mm, in.) 34, 2.91 20, 2.36 34, 2.91 54, 3.7
Max. Overall Diameter (mm, in.) 7, 0.28 7, 0.28 7, 0.28 7, 0.28
Window Recess (mm, in.) N/A N/A N/A N/A
* An exposure of 115.07 mR in air equates to 1.0 mGy.
*** At recommended operating voltage.
The T2422 detector is equivalent to the 3G10.
Detector Type Applications
T2411 Dosimeters
T2411M Military
T2416A Dosimeters, Small Portable Monitors
T2417A Dosimeters, Small Portable Monitors, Military
T2420M Military
T2422 Dosimeters, Small Portable Monitors
Related Industry Models
CANBERRA Centronics LND Saint Gobain
Miniature Detectors T2411 ZP1310 714 N116-1/C131