Highpurity germanium hpge detectors can be produced from germanium material enriched in 76ge, which serves simultaneously as a source and as detector medium. High purity germanium hpge detectors remain the recognized gold standard for high resolution gammaray spectroscopy. The impact of the procedure and geometry on the detector performance was analyzed for eight detectors. International journal of applied radiation and isotopes, vol. High purity germanium detectors are mostly used for gamma spectroscopy in nuclear physics, as well as xray spectroscopy. 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. Germanium well detectors are made from high purity germanium and can therefore be shipped and stored at room temperature without harm. Portable electromechanically cooled highresolution. The detector array is suspended in a liquid argon cryostat lined with copper and surrounded by an ultrapure water tank. Newly designed lowbackground detector shields for radiation measurement applications. High purity germanium detector calibration at isolde. 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. Calibration of hpge gammaray planar detector system for. High purity germanium detector calibration at isolde gu.
It can be made in large volumes to detect high energies and when operating at cryogenic temperatures it has. Learn more about ortecs high purity germanium radiation detectors hpge today. 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. I have a question regarding gamma ray detector, the high purity germanium detector or aka hpge. A prototype high purity germanium detector for high. Segmented planar high purity germanium detectors were developed. The conventional coaxial germanium detector is often referred to as pure ge, hpge, intrinsic ge, or hyperpure ge. 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. Calculation of the peak efficiency of highpurity germanium. If silicon or germanium of normal semiconductor purity is employed. The detector consists of an ntype hpge crystal, 60mm in diameter and 90mm in length, with 36fold segmentation of the outer boron implanted contact. What is high purity germanium detector hpge definition. The response of a highpurity germanium detector to xrays in the 815kev energy region has been investigated.
With an atomic number of 32, germanium has a much higher photoelectric cross section than silicon atomic. High purity germanium detector array spie digital library. For high purity germanium detectors, the fwhm of the 32. Highpurity germanium detectors hpge detectors are the best solution for precise gamma and xray spectroscopy. Pdf high purity germanium koya4039 gamma detection system. These detectors are made of high purity germanium hpge ptype and n, or silicon lithium sili. The highly pure germanium detector is designed to be sensitive to low energy dark matter flux. The core part of the detector consists of three encapsulated, 36fold segmented, highpurity germanium detectors hpge which are operated in a common cryostat. These detectors are also called highpurity germanium detectors hpge or. Topsil hps float zone silicon for detectors has the following unique. The experiment uses high purity enriched ge crystal diodes as a beta decay source and particle detector. 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. Performance of the ultrahigh rate germanium uhrge system.
Highpurity germanium detector ionization pulse shapes of. Highpurity germanium for gamma detectors technical. The purpose of this project was to develop a compact, modular multichannel xray detector with integrated electronics. 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 following are five things you need to know about the use of hpge detector systems for homeland security applications in the field. 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. In gerda phasei, reprocessed enrichedge detectors, which were previously. Index termsneutrinoless double beta decay, gerda, hpge detector, liquid argon. 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. 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. Why high purity germanium hpge radiation detection. The detector energy resolution follows a characteristic. Youngman, evaluation of a high purity germanium detector body monitor, radiation protection dosimetry, volume 53, issue 14, 1 may 1994.
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. 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. Performance of bare highpurity germanium detectors in. Pulse shapes of recoil events from neutron scattering inside a germanium detector were collected for the first time. Otherwise, leakage current induced noise destroys the energy resolution of the detector. The wvalue and energy resolution dependencies on the xray energy have been studied. High purity germanium hpge is the only radiation detection.
Pdf the impact of high purity germanium gamma detection system koya4039 will be presented. Other articles where germanium detector is discussed. Square hole collimators have been fabricated with design parameters that exploit the unique characteristics of the detector. Twodetector, 512element high purity germanium camera prototype abstract. The first gamma ray spectrometer is the one dimensional high purity germanium spectrometer. Two types of geometry were used to fabricate hpge detectors. Characterization of high purity germanium point contact. 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. 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. 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. We measured full energy peak efficiency of high purity germanium detector which is important for gammaray spectrometry experiments.
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. Ptype point contact germanium detectors and their application in. High purity germanium detector in gammaray spectrometry. Energy and efficiency calibrations for high purity. Amorphous germanium age contacts are used for blocking both electrons and holes. Germanium detectors germanium short form catalog in pdf format j16 series detectors are highquality germanium photodiodes designed for the 800 to 1800nm wavelength range. Therefore we conclude that we have measured recoil events from elastically scattered neutrons inside the germanium detector. 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. 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. 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. We use cookies to make interactions with our website easy and meaningful, to better understand the use of our services, and to tailor advertising.
Canberra models gc7020 old, from 1990, and gx6020 new, from. Pdf energy and efficiency calibrations for high purity. Ssbi can offer the optimum detector for a wide range of applications. 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.
Highpurity germanium detector ionization pulse shapes of nuclear recoils. Ortec provides a comprehensive suite of hpge radiation detector solutions covering an extensive range of energies and for a variety of applications. The detectors from the hdm and igex experiments were reprocessed and used in phase 1. We measured full energy peak efficiency of highpurity germanium detector which is important for gammaray spectrometry experiments. Detector fabrication and performance article pdf available in ieee transactions on nuclear science ns191. The response of highpurity germanium detectors to xrays. The printed circuit boards pcb containing the cooled electronics. 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. As a result, the fabrication process of small planar detectors at usd is discussed in great detail.
Resolution and efficiency of high purity germanium detector. On the underground production of high purity germanium detectors. This article is about ionizing radiation detectors. Hpge detectors have a 2030x improvement in resolution as compared to that of. We present an initial evaluation of a mechanicallycooled, highpurity germanium doublesided strip detector as a potential gamma camera for smallanimal spect. It is 90 mm in diameter and 10 mm thick with two sets of 16 orthogonal strips that have a 4. The authors declare having no conflict of interest. Both energy resolution and efficiency will be explored as a function of ray energy. The ultimate result of this analysis would be the deployment of this detector on an autonomous robot for sample collection and remote analysis. In this case, however, it is advantageous to choose germanium rather than silicon as the detector material.
High purity germanium detectors hpge are not just laboratory instruments anymore. 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. Detailed specifications are available for j16 series room temperature detectors, parallel output arrays, avalanche photodiodes and two color detectors. 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. The germanium detector array, gerda, will search for neutrinoless double beta decay in 76ge at the national gran sasso laboratory of the infn. There are three different effects that can modify the size and shape of a charge cloud as it moves through a germanium detector. For photon spectroscopy in the energy region of hundred kev or several mev, much thicker semiconductor. 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. Fabrication and characterization of highpurity germanium. To free one photoelectron from the pmts photocathode. On the underground production of high purity germanium detectors mikael hult1, sergey belogurov2, allan caldwell3. Installation setup of a highpurity germanium hpge nuclear spectroscopy system. Signal modeling of highpurity ge detectors with a small read. We use both ptype and ntype germanium and we use diffused, implanted, and.
A cryogenic lownoise jfetcmos preamplifier for the hpge. The first triple cluster detector was successfully assembled for the next generation highresolution gammaray spectrometer. Characterization of mechanically cooled high purity germanium. No abrupt variation of wis observed at the germanium k absorptionedge 11. The present disclosure provides a highpurity germanium hpge detector, comprising. Digital timing algorithm for high purity germanium detectors. For applications where temperature stability of response is important near the cutoff, thermoelectrically cooled detectors are available. Why high purity germanium hpge radiation detection technology is superior to other detector technologies for isotope identification synopsis.
For semiconductor detectors in radio, see detector radio, crystal detector, semiconductor diodes, and rectifier. 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. From the photon mean free path in germanium, a detector thickness of the order of 5 cm is required for efficient detection of. Segmentation of pn junction was performed by implantation of boron for the ntype ge and mechanical grooving of the li diffusion. Lowbackground germanium spectroscopy shields for radiation. 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. 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. Characterization of high purity germanium point contact detectors with low net impurity concentration. This summer student project involved the test and calibration of two high purity coaxial germanium gammaray detectors. As a result, the fabrication process of small planar detectors at usd was discussed in great detail. A highpurity germanium detector was modeled in mcnp6.
Characterization of a highpurity germanium detector for. Pdf the availability of germanium with less than 1010 acceptorscm3 has enabled us to fabricate and study the performance of. We present an initial evaluation of a mechanically cooled, highpurity germanium doublesided strip detector as a potential gamma camera for smallanimal spect. Five things you need to know about using highpurity. Appendix c truck mounted high purity germanium detector surveys. 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. On the underground production of high purity germanium. Twodetector, 512element high purity germanium camera. High purity germanium detector repair conference osti.
The present disclosure provides a high purity germanium hpge detector, comprising. What is meant by the detection efficiency at specific gammaray energy. Presentation mode open print download current view. High purity germanium hpge is widely used xray and. A brief but very effective description on the basic formation.
Unlike lithiumdrifted detectors, high purity germanium detectors may be cycled repeatedly between ln 2 and room temperature with no compromise in performance. Semiconductor detectors find broad application for radiation protection, gamma and xray spectrometry, and as particle detectors. High purity germanium hpge radiation detectors products. The performance of the germanium ge detector body monitor that has been recently installed at nrpb chilton is evaluated and compared with the perfo. Calculation of the peak efficiency of highpurity germanium detectors. This does not come better than in topsil high purity silicon hps. Gamma background studies for the xenon experiment using a high purity germanium detector by jesse isaac angle may 2008 chair. High purity germanium spectroscopy system north american. Sep 16, 2011 a high purity germanium hpge detector is the ultimate instrument for energy spectrometry of gamma radiation. Comparison of a high purity germanium gamma ray spectrometer.
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 measured ionization efficiencies of recoiling germanium atoms in germanium are in good agreement with the theory of lindhard and earlier measurements. For applications where temperature stability of response is important near. A semiconductor detector in ionizing radiation detection physics is a device that uses a. Evaluation of a high purity germanium detector body. Performance of bare highpurity germanium detectors in liquid. We use both ptype and ntype germanium and we use diffused, implanted, and barrier contacts to achieve this product variety. For more information please contact natsusa at 8606356820. Digital gammaray spectroscopy with high purity germanium. High purity germanium detector array, proceedings of spie. The dependence of the energy resolution on the shaping parameter will be investigated.
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. 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. 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. Use of a highpurity germanium semiconductor detector for. Jra2 is named integrated double beta decay idea and it aims to further develop and integrate the. This coaxial detector is available in an energy range of 40kev to 10 mev and offers high efficiency of radiation detection. These crystals should not have a net electrically active impurity concentration greater than 10 l0 cm. 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 best choice of high purity germanium hpge detector detector efficiencye the detector efficiency in eq. To complete the gamma spectroscopy laboratory set caen sys includes in its offer a wide choice of high purity germanium detectors hpge. Some of the features that make silicon an excellent choice of material are the purity and the absence of dislocations, defects, and impurities. 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. 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. Because the issue with leakage current only applies during operation, hpge.
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. Portable electromechanically cooled highresolution germanium detector kenneth w. 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. Semiconductor detectors also can be used in gammaray spectroscopy. Energy and efficiency calibrations for high purity germanium gem30195 coaxial detector using k0iaea software. Germanium detectors are semiconductor diodes having a pin structure in which the intrinsic i region is sensitive to ionizing.
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