On the underground production of high purity germanium detectors mikael hult1, sergey belogurov2, allan caldwell3, josef janicsko3, vasiliy kornoukhov2,4, stefan schonert5 1 european commissionjoint research centreinstitute for reference materials and measurements ecjrcirmm, geel, belgium. High purity germanium hpge detectors remain the recognized gold standard for high resolution gammaray spectroscopy. Calculation of the peak efficiency of highpurity germanium detectors. It is 90 mm in diameter and 10 mm thick with two sets of 16 orthogonal strips that have a 4. For applications where temperature stability of response is important near. The following are five things you need to know about the use of hpge detector systems for homeland security applications in the field. Pulse shapes of recoil events from neutron scattering inside a germanium detector were collected for the first time. High purity germanium spectroscopy system north american. On the underground production of high purity germanium detectors mikael hult1, sergey belogurov2, allan caldwell3.
The impact of the procedure and geometry on the detector performance was analyzed for eight detectors. For semiconductor detectors in radio, see detector radio, crystal detector, semiconductor diodes, and rectifier. Portable electromechanically cooled highresolution. A brief but very effective description on the basic formation. Amorphous germanium age contacts are used for blocking both electrons and holes. Pdf high purity germanium koya4039 gamma detection system. High purity germanium detector calibration at isolde gu. For more information please contact natsusa at 8606356820. Characterization of high purity germanium point contact detectors with low net impurity concentration. The core part of the detector consists of three encapsulated, 36fold segmented, highpurity germanium detectors hpge which are operated in a common cryostat. Introduction use of segmented high purity germanium hpge detectors is foreseen in the gerda experiment germanium detector array 1,2 in the search of neutrinoless doublebeta decay of 76ge. These detectors are also called highpurity germanium detectors hpge or. The best choice of high purity germanium hpge detector detector efficiencye the detector efficiency in eq.
Square hole collimators have been fabricated with design parameters that exploit the unique characteristics of the detector. Highpurity germanium for gamma detectors technical. Evaluation of a high purity germanium detector body. The response of highpurity germanium detectors to xrays. The first gamma ray spectrometer is the one dimensional high purity germanium spectrometer. Signal modeling of highpurity ge detectors with a small read. Twodetector, 512element high purity germanium camera prototype abstract.
Germanium well detectors are made from high purity germanium and can therefore be shipped and stored at room temperature without harm. The present disclosure provides a high purity germanium hpge detector, comprising. Digital timing algorithm for high purity germanium detectors. There are three different effects that can modify the size and shape of a charge cloud as it moves through a germanium detector. Detector fabrication and performance article pdf available in ieee transactions on nuclear science ns191. For applications where temperature stability of response is important near the cutoff, thermoelectrically cooled detectors are available.
From the photon mean free path in germanium, a detector thickness of the order of 5 cm is required for efficient detection of. For the nuclear hobbyist, an hpge opens a window into a fascinating realm of homeaccessible, lowintensity nuclear reactions that are obscured by background in other detectors lacking the superlative resolution. Index termsneutrinoless double beta decay, gerda, hpge detector, liquid argon. The invention discloses a high purity germanium detector, which comprises a high purity germanium crystal, a first electrode and a second electrode, and a conductive protection ring, wherein the high purity germanium crystal has an intrinsicregion exposed surface. Gamma background studies for the xenon experiment using a high purity germanium detector by jesse isaac angle may 2008 chair.
High purity germanium hpge radiation detectors products. Other articles where germanium detector is discussed. Standard shields are offered with thicknesses of up to 6inches 15cm, and are copper and tin lined to completely encapsulate the lead and eliminate exposure to the user. Using this model and the source term, the predicted response spectrum for each fallout composition was generated and compared using genie spectroscopy software in an attempt to find differentiating features between them. Presentation mode open print download current view. We present an initial evaluation of a mechanically cooled, highpurity germanium doublesided strip detector as a potential gamma camera for smallanimal spect.
In comparison to silicon detectors, germanium is much more efficient than silicon for radiation detection due to its atomic number being much higher than silicon and due to lower average energy necessary to create an electronhole pair, which is 3. Ptype point contact germanium detectors and their application in. The germanium crystals used for the fabrication of nuclear radiation detectors are required to have a purity and crystalline perfection which is unsurpassed by any other solid material. High purity germanium hpge is the only radiation detection technology that provides sufficient information to accurately and reliably identify radionuclides from their passive gamma ray emissions. Otherwise, leakage current induced noise destroys the energy resolution of the detector. Characterization of mechanically cooled high purity germanium. The detector type is high purity germanium, which is a semiconductor that must be temperature controlled with liquid nitrogen to 77 k due to excessive leakage current at higher temperatures 2. The ultra high rate germanium uhrge project goal was to develop technology to operate high purity germanium hpge detectors with high throughput 85% in environments with incoming gammaxray event rates r106 s. The dependence of the energy resolution on the shaping parameter will be investigated. The detector consists of an ntype hpge crystal, 60mm in diameter and 90mm in length, with 36fold segmentation of the outer boron implanted contact.
Because the issue with leakage current only applies during operation, hpge. Ortec provides a comprehensive suite of hpge radiation detector solutions covering an extensive range of energies and for a variety of applications. High purity germanium detector calibration at isolde. Two types of geometry were used to fabricate hpge detectors. On the underground production of high purity germanium. For photon spectroscopy in the energy region of hundred kev or several mev, much thicker semiconductor. Highpurity germanium detectors hpge detectors are the best solution for precise gamma and xray spectroscopy. High purity germanium detectors hpge are not just laboratory instruments anymore. Germanium detectors are semiconductor diodes having a pin structure in which the intrinsic i region is sensitive to ionizing. The experiment uses high purity enriched ge crystal diodes as a beta decay source and particle detector. We use cookies to make interactions with our website easy and meaningful, to better understand the use of our services, and to tailor advertising. Calculation of the peak efficiency of highpurity germanium. High purity germanium hpge is widely used xray and.
Truck mounted high purity germanium detector surveys this appendix provides figures that were generated using the ineels truck mounted high purity germanium detectors either on a hummer or other fourwheel drive vehicle to perform field screening of the tsf06 area b and tsf26 sites for cs 7. Unlike lithiumdrifted detectors, high purity germanium detectors may be cycled repeatedly between ln 2 and room temperature with no compromise in performance. Jra2 is named integrated double beta decay idea and it aims to further develop and integrate the. Appendix c truck mounted high purity germanium detector surveys. Bare highpurity germanium detectors enriched in 76ge will be submerged in liquid argon serving simultaneously as a shield against external radioactivity and as a cooling medium. Detailed specifications are available for j16 series room temperature detectors, parallel output arrays, avalanche photodiodes and two color detectors. As a result, the fabrication process of small planar detectors at usd is discussed in great detail.
Use of a highpurity germanium semiconductor detector for. The first triple cluster detector was successfully assembled for the next generation highresolution gammaray spectrometer. Both energy resolution and efficiency will be explored as a function of ray energy. High purity germanium remains the material of choice for the detection of photons in the range of mev or higher, down to the hard xray range. We present an initial evaluation of a mechanicallycooled, highpurity germanium doublesided strip detector as a potential gamma camera for smallanimal spect. The authors declare having no conflict of interest. Energy and efficiency calibrations for high purity. It can be made in large volumes to detect high energies and when operating at cryogenic temperatures it has. Characterization of a highpurity germanium detector for. Since the operation of hpgebased detectors is possible only at or below the liquid nitrogen temperature, their advantage is mainly the resolution, which matches the fano factor if appropriate cooled electronic readout is used.
A semiconductor detector in ionizing radiation detection physics is a device that uses a. Pdf the availability of germanium with less than 1010 acceptorscm3 has enabled us to fabricate and study the performance of. A semiconductor detector in ionizing radiation detection physics is a device that uses a semiconductor usually silicon or germanium to measure the effect of incident charged particles or photons. The wvalue and energy resolution dependencies on the xray energy have been studied. A prototype high purity germanium detector for high. This article is about ionizing radiation detectors. Results obtained as a function of the photon input rate, energy resolution, and techniques for correcting for pulse overlap at high count rates will be discussed. Highpurity germanium detector ionization pulse shapes of. Highpurity germanium detector ionization pulse shapes of nuclear recoils. We measured full energy peak efficiency of high purity germanium detector which is important for gammaray spectrometry experiments. Energy and efficiency calibrations for high purity germanium gem30195 coaxial detector using k0iaea software. The detector array is suspended in a liquid argon cryostat lined with copper and surrounded by an ultrapure water tank. Five things you need to know about using highpurity. In this case, however, it is advantageous to choose germanium rather than silicon as the detector material.
Ssbi can offer the optimum detector for a wide range of applications. The measured ionization efficiencies of recoiling germanium atoms in germanium are in good agreement with the theory of lindhard and earlier measurements. Why high purity germanium hpge radiation detection. These crystals should not have a net electrically active impurity concentration greater than 10 l0 cm.
Installation setup of a highpurity germanium hpge nuclear spectroscopy system. What is meant by the detection efficiency at specific gammaray energy. Germanium detectors germanium short form catalog in pdf format j16 series detectors are highquality germanium photodiodes designed for the 800 to 1800nm wavelength range. The purpose of this research is to investigate the feasibility of using a high purity germanium double sided strip detector hpgedssd to image special nuclear material snm for use in the field of nuclear nonproliferation. The printed circuit boards pcb containing the cooled electronics. The detectors from the hdm and igex experiments were reprocessed and used in phase 1. The ultimate result of this analysis would be the deployment of this detector on an autonomous robot for sample collection and remote analysis.
Digital gammaray spectroscopy with high purity germanium. Semiconductor detectors find broad application for radiation protection, gamma and xray spectrometry, and as particle detectors. Why high purity germanium hpge radiation detection technology is superior to other detector technologies for isotope identification synopsis. This does not come better than in topsil high purity silicon hps. High purity germanium detectors are mostly used for gamma spectroscopy in nuclear physics, as well as xray spectroscopy. Therefore we conclude that we have measured recoil events from elastically scattered neutrons inside the germanium detector. I have a question regarding gamma ray detector, the high purity germanium detector or aka hpge. Canberra models gc7020 old, from 1990, and gx6020 new, from. Introduction t he germanium detector array, gerda, will search for neutrinoless double beta decay 0 in 76ge 1 with the goal to investigate the nature of neutrinos and their mass.
All our measurements were done using highpurity coaxial germanium detector hpge model number 30195 ortec with relative efficiency of cm30% and a resolution of 1. The present disclosure provides a highpurity germanium hpge detector, comprising. Learn more about ortecs high purity germanium radiation detectors hpge today. Topsil hps float zone silicon for detectors has the following unique. Regardless of the superlative used, the detector is basically a cylinder of germanium with an ntype contact on the outer surface, and a ptype contact on the surface of an axial well. High purity germanium hpge is the only radiation detection. Physics the xenon dark matter experiment, deployed at the gran sasso national laboratory in italy on march 2006, is a liquid noble gas detector designed to directly detect dark matter. High purity germanium detector array spie digital library. Because germanium has relatively low band gap, these detectors must be cooled in order to reduce the thermal generation of charge carriers thus reverse leakage current to an acceptable level. A prototype high purity germanium detector array designed for use in the pulse height analysis mode as a discrete photon energy detector for medical imaging was fabricated and tested. The response of a highpurity germanium detector to xrays in the 815kev energy region has been investigated.
This coaxial detector is available in an energy range of 40kev to 10 mev and offers high efficiency of radiation detection. Semiconductor detectors also can be used in gammaray spectroscopy. Pdf energy and efficiency calibrations for high purity. Newly designed lowbackground detector shields for radiation measurement applications. Making a high purity ge rmanium detector 1 start with highpurity, ntype ge crystal. The highly pure germanium detector is designed to be sensitive to low energy dark matter flux. We use both ptype and ntype germanium and we use diffused, implanted, and. On the underground production of high purity germanium detectors. Highpurity germanium hpge detectors can be produced from germanium material enriched in 76ge, which serves simultaneously as a source and as detector medium.
Germanium detector how is germanium detector abbreviated. We use both ptype and ntype germanium and we use diffused, implanted, and barrier contacts to achieve this product variety. Introduction silicon semiconductor detectors described in the previous chapter have depletion depths less than 1 mm, which are sufficient for charged particle spectroscopy or soft xray detection. Digital timing algorithm for high purity germanium detectors knox andrew, university of massachusetts lowell, krzysztof starosta, david miller, constantin vaman, phillip voss, dirk weisshaar, michigan state universitynational superconduction cyclotron labratory the next generation of ray detector arrays will be composed of large volume high. A highpurity germanium detector was modeled in mcnp6. The conventional coaxial germanium detector is often referred to as pure ge, hpge, intrinsic ge, or hyperpure ge. High purity germanium detector repair conference osti. A cryogenic lownoise jfetcmos preamplifier for the hpge. Some of the features that make silicon an excellent choice of material are the purity and the absence of dislocations, defects, and impurities. High purity germanium detector in gammaray spectrometry. Performance of bare highpurity germanium detectors in. The germanium detector array, gerda, will search for neutrinoless double beta decay in 76ge at the national gran sasso laboratory of the infn. This summer student project involved the test and calibration of two high purity coaxial germanium gammaray detectors.
Performance of bare highpurity germanium detectors in liquid. Youngman, evaluation of a high purity germanium detector body monitor, radiation protection dosimetry, volume 53, issue 14, 1 may 1994. This work investigates the ability of a high purity germanium detector to perform postdetonation forensics on the debris from several types of nuclear weapons 24 hours after detonation. If silicon or germanium of normal semiconductor purity is employed. With an atomic number of 32, germanium has a much higher photoelectric cross section than silicon atomic.
These detectors are made of high purity germanium hpge ptype and n, or silicon lithium sili. Calibration of hpge gammaray planar detector system for. The advantages of the intrinsic radiopurity and excellent spectroscopic performance 2 3 kev full width at half maximum resolution at qbb 2039 kev of hpge detectors have. As a result, the fabrication process of small planar detectors at usd was discussed in great detail. Twodetector, 512element high purity germanium camera.
Performance of the ultrahigh rate germanium uhrge system. The purpose of this project was to develop a compact, modular multichannel xray detector with integrated electronics. Ortec offers a broad range of semiconductor photon detectors and options, as can be seen in the figure, covering energies in a range from a few hundred ev to 10mev gamma ray and upper. Ruhter lawrence livermore national laboratory livermore, ca 94550 usa abstract we have integrated a small, highlyreliable, electromechanical cryocooler with a high resolution germanium detector for portablefield applications. Segmented planar high purity germanium detectors were developed. Segmentation of pn junction was performed by implantation of boron for the ntype ge and mechanical grooving of the li diffusion. We measured full energy peak efficiency of highpurity germanium detector which is important for gammaray spectrometry experiments. Resolution and efficiency of high purity germanium detector. Lowbackground germanium spectroscopy shields for radiation. The detector energy resolution follows a characteristic. The excellent energy resolution that hpge detectors afford often makes them the detector of choice for applications as diverse as nuclear physics research, medical imaging, homeland security, and environmental monitoring.
Characterization of high purity germanium point contact. The performance of the germanium ge detector body monitor that has been recently installed at nrpb chilton is evaluated and compared with the perfo. In comparison to silicon detectors, germanium is much more efficient than silicon for radiation detection due to its atomic number being much higher than silicon and due to lower average energy necessary to create an electronhole. This detector, based upon emerging silicon drift detector sdd technology, will be capable of high data rate operation superior to the current state of the art offered by high purity germanium hpge detectors, without the need for liquid nitrogen. In gerda phasei, reprocessed enrichedge detectors, which were previously.
For high purity germanium detectors, the fwhm of the 32. No abrupt variation of wis observed at the germanium k absorptionedge 11. Portable electromechanically cooled highresolution germanium detector kenneth w. Comparison of a high purity germanium gamma ray spectrometer. What is high purity germanium detector hpge definition. International journal of applied radiation and isotopes, vol. Sep 21, 2011 we present an initial evaluation of a mechanicallycooled, high purity germanium doublesided strip detector as a potential gamma camera for smallanimal spect. To complete the gamma spectroscopy laboratory set caen sys includes in its offer a wide choice of high purity germanium detectors hpge. The high purity germanium spectroscopy detector is used in the detection and analysis of gammaray of environmental objects in nuclear energetics, products of industry and agriculture, medicine, etc.
Hpge detectors have a 2030x improvement in resolution as compared to that of. Calibration of hpge gammaray planar detector system for radioactivity standards tidatrut vichaidid 1, thongchai soodprasert1 and teerasak verapaspong2 abstract quantitative analysis of radioactive materials using efficiency calibration of gamma ray high purity germanium planar detector system has been studied. High purity germanium detector array, proceedings of spie. To free one photoelectron from the pmts photocathode. Hyperpure germanium detector introduction the aim of this experiment is to be familia r with a hyperpure germ anium hpge detector used as a ray spectrometer.
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