Tl detectors as compared to high purity germanium hpge detectors. High purity germanium detector calibration at isolde. 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. The temperature sensitivity of surface channel effects on planar high purity germanium detectors was measured using 60kev gammaray scanning techniques, as part of a radiation damage study.
The detectors i worked with are referred to as a coaxial ge detectors, high purity. Ppc detectors have several characteristics that make them well suited for a 76 ge 0. Title christopher leslie csiro land and water science report 1209 may 2009 analysing environmental radioactivity in soils and sediments using high purity germanium gamma detectors. Characterization of an hpge detector for experiments. Fabrication process development for high purity germanium. The characterisation of agata high purity germanium detectors.
Characterization of mechanically cooled high purity germanium. These crystals should not have a net electrically active impurity concentration greater than 10 l0 cm. Introduction gammaray spectrometry using high purity germanium hpge detectors has been an essential and principal corresponding author. The accuracy of beam energy depends solely on the detection results of hpge detector. Hpge detectors excel in gammaray spectroscopy, offering excellent energy resolution with large detector sizes for high. Di erent variations of ge detectors are available from commercial manufacturers, which have di erent performance characteristics.
With an atomic number of 32, germanium has a much higher photoelectric cross section than silicon atomic. Hpge detectors are operated in vacuum at liquid nitrogen. The nitrospec the worlds smallest liquid nitrogen cooled spectrometer which is based on high purity germanium hpge semiconductor detectors. For photon spectroscopy in the energy region of hundred kev or several mev, much thicker semiconductor detectors are required. The present disclosure provides a high purity germanium hpge detector, comprising. Neutron damage in mechanicallycooled highpurity germanium. The applications were then shifted to a key component in fiber optics, infrared night vision devices and space solar cells, as well as a polymerization. On the underground production of high purity germanium. Germanium detectors are semiconductor diodes having a pin structure in which the intrinsic i region is sensitive to ionizing radiation, particularly x rays and gamma rays.
Hpge spectrometer based on coaxial detector gcd liquid. Pdf the impact of high purity germanium gamma detection system koya4039 will be presented. In this work, the aim is to improve the technique of get for irradiated nuclear fuel, by developing a detector concept that allows for a higher spatial resolution andor faster interrogation. Planar configuration an example of a planar hpge detector using a ptype crystal is shown in fig. Autohpge, an autosampler for gammaray spectroscopy using high purity germanium hpge detectors and heavy shields matheus c. No abrupt variation of wis observed at the germanium k absorptionedge 11. Hyperpure germanium hpge detector fabrication 4 hpge crystal were first developed in the mid 1970s. Jan 25, 2020 in this work, the aim is to improve the technique of get for irradiated nuclear fuel, by developing a detector concept that allows for a higher spatial resolution andor faster interrogation. Making high purity germanium crystalgrownbypullingfrommoltenge czochralskitechnique seedcrystalslowlywithdrawn. The purpose of this thesis is to assemble a hpge detector intended to be used in a mass. 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.
Using sup 14cspiked pyrolytic graphitecoated quartz crucibles for the growth of nine ultrapure germanium single crystals, we have determined the carbon content and distribution in these crystals. Resolution and efficiency of high purity germanium detector a project by abhigyan. 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. Matheus carvalho updated the license of autohpge, an autosampler for gammaray spectroscopy using high purity germanium hpge detectors and heavy shields to. For the gerda experiment it is absolutely vital that the germanium detectors are not exposed to cosmic rays or at least that the exposure is kept to a minimum. High purity germanium crystal growth at university of. Pdf resolution and efficiency of high purity germanium. Determination of the photopeak detection efficiency of a. The type depends on the concentration of donor or acceptor atoms in the crystal. The mirion 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. In rare event searches, such as neutrinoless double beta decay, the pointcontact geometry is of particular importance since it allows for pulseshape discrimination, and therefore for a significant background reduction. Its first commercial usage as the main material, from which the semiconductors were made, was later replaced by silicon. Operation of a high purity germanium crystal in liquid argon.
Cooling system for the highpurity germanium hpge detector. Hpge tennessee research and creative exchange university of. Germanium detectors are essential instruments in high resolution ray spectroscopy applications. 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. High purity germanium hpge radiation detectors are well established as a valuable tool in nuclear science, astrophysics, and nuclear security applications. For example, the company that became fairchild semiconductor was founded in 1957 with the express purpose of producing silicon transistors. High purity germanium hpge gamma ray detectors have proven be essential for environmental, geological, and atmospheric research. Hpge detectors for dark matter and neutrino physics. 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. Using autoradiography, we observe a rapidly decreasing carbon cluster concentration in successively grown crystals. This coaxial detector is available in an energy range of 10 kev to 10 mev and offers high efficiency of radiation detection.
Manukyan et althis content was downloaded from ip address 40. Gaussian energy broadening function of an hpge detector in. Best choice of high purity germanium hpge detector ortec. 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. Adapting the electron beam from sem as a quantitative heating source for nanoscale thermal metrology. Autohpge, an autosampler for gammaray spectroscopy using high purity germanium hpge detectors and heavy shields article pdf available august 2018 with 316 reads how we measure reads. We use both ptype and ntype germanium and we use diffused, implanted, and barrier contacts to achieve this product variety. Fieldportable systems, such as idaho national laboratorys pins system, have used standard liquidnitrogencooled high purity germanium hpge detectors to perform this. High purity germanium detectors are mostly used for gamma spectroscopy in nuclear physics, as well as xray spectroscopy. Other articles where germanium detector is discussed. Oct 01, 20 prompt gamma neutron activation pgnaa systems require the use of a gammaray spectrometer to record the gammaray spectrum of an object under test and allow the determination of the objects composition. In this paper we investigate the pulseshape discrimination performance of ultra high purity germanium point contact detectors. High purity germanium hpge detectors are widely used in nuclear spectroscopy e. High purity germanium detector disconnected from liquid nitrogen dewar germanium detectors are mostly used for gamma spectroscopy in nuclear physics, as well as xray spectroscopy.
Gamma background studies for the xenon experiment using a high purity germanium detector by jesse isaac angle may 2008 chair. Semiconductor detectors also can be used in gammaray spectroscopy. Ssbi can offer the optimum detector for a wide range of applications. High purity germanium hpge radiation detectors products. The ultimate result of this analysis would be the deployment of this detector on an autonomous robot for sample collection and remote analysis. A 24% intrinsic ptype germanium blindhole coaxial detector was used in this work. High purity germanium detector to determine the true cause of the radiation. Calculation of efficiency of high purity germanium hpge detector master of science in applied physics. Learn more about ortecs high purity germanium radiation detectors hpge today. Detection of radiation in any spatial orientation depending on cryostat modification. On the underground production of high purity germanium detectors. Energy linearity of highpurity germanium detectors in the. Fieldportable systems, such as idaho national laboratorys pins system, have used standard liquidnitrogencooled highpurity germanium hpge detectors to perform this function. The high purity germanium hpge spectrometer is used for analysis of environmental sample and determination of radioisotope concentration due to its excellent resolution.
Although already of very high purity, the material is further purified with the zone refining technique. Characterization of high purity germanium point contact. 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. Resolution function of a gmx series coaxial detector system model number gmx40p483 in the range of 40 kev to 1. Information on specific application of gammaray spectrometry is also available in the. Gammaray energies will be measured with a high purity germanium hpge detector and researchgrade electronics.
A clover detector is a gammaray detector that consists of 4 coaxial ntype high purity germanium ge crystals each machined to shape and mounted in a common cryostat to form a structure resembling a fourleaf clover. In this case, however, it is advantageous to choose germanium rather than silicon as the detector material. For this reason this report is a deliverable also in idea. Olivares philippine nuclear research institute, commonwealth avenue, diliman, quezon city, metro manila, philippines. Large volume high purity germanium arrays, very high beam intensities and more recently exotic beams have lead to new understanding of nuclear physics. Signal modeling of highpurity ge detectors with a small read. We present an initial evaluation of a mechanicallycooled, highpurity germanium doublesided strip detector as a potential gamma camera for smallanimal spect. For high purity germanium detectors, the fwhm of the 32. Otherwise, leakage current induced noise destroys the energy resolution of the detector.
The response of a highpurity germanium detector to xrays in the 815kev energy region has been investigated. Analysing environmental radioactivity in soils and. Resolution and efficiency of high purity germanium detector. The response of highpurity germanium detectors to xrays. To complete the gamma spectroscopy laboratory set caen sys includes in its offer a wide choice of high purity germanium detectors hpge. Pdf resolution and efficiency of high purity germanium detector.
Sanders, ceylena holloway radionuclide measurements have proven to be essential for determining processes related to pressing environmental issues as well as reconstructing historical events related to natural and anthropogenic activities. While silicon detectors cannot be thicker than a few millimeters, germanium can have a depleted, sensitive thickness of centimeters, and therefore can be used as. Why high purity germanium hpge radiation detection. The gamma ray transport algorithms and benchmark experiments have helped to lay a foundation for creating detector response function methods, even in high purity germanium hpge type detectors. High precision scans of the detector crystal and gammaray source measurements have been compared to montecarlo simulations to adjust the dimensions of a detector model. Semiconductor detectors find broad application for radiation protection, gamma and xray spectrometry, and as particle detectors. Detector fabrication and performance article pdf available in ieee transactions on nuclear science ns191. The advanced gamma tracking array agata aims to utilise high purity germanium hpge detectors in order to achieve a dramatic increase in efficiency over current spectrometers.
Highpurity germanium hpge detectors are widely used in nuclear spectroscopy e. High purity germanium hpge detectors and spectrometers for gamma analysis, waste management, environmental monitoring, laboratory analysis, insitu measurements, homeland security, health physics, lowbackground measurements. Under reverse bias, an electric field extends across the intrinsic or depleted region. Furthermore, the work on detector response functions using the ceardrfs code from gardner et al. This detector has better characteristics and more sensitive to the detection of impurities attix, 1986. From 1950 through the early 1970s, this area provided an increasing market for germanium, but then high purity silicon began replacing germanium in transistors, diodes, and rectifiers. Calibration of hpge gammaray planar detector system for. The high purity germanium detectors hpge complete set is composed by the following components.
A high purity germanium detector was modeled in mcnp6. This summer student project involved the test and calibration of two high purity coaxial germanium gammaray detectors. On two cryogenic systems of high purity germanium detector. The mirion intelligent preamplifier ipa for high purity germanium hpge detectors is a lownoise, high speed resistive feedback preamplifier designed for high resolution gamma spectroscopy and timing measurements. Carbon in highpurity germanium unt digital library. Use of a highpurity germanium semiconductor detector for. The starting material is bulk germanium intended for the semiconductor industry.
This relatively high value is of practical concern since high purity germanium hpge is often the detector of choice for a and xray spectrometry. Determination of the photopeak detection efficiency of a hpge. Pdf the availability of germanium with less than 1010 acceptorscm3 has enabled us to fabricate and study the performance of germanium detectors of. Characterization of a highpurity germanium detector for. Since the early 1950s the use of germanium has been continuously growing as new applications are being developed. Liquid nitrogen ln 2 or electromechanical cooling system are both available.
The detector energy resolution follows a characteristic. High purity germanium detector calibration at isolde gu. What is meant by the detection efficiency at specific gammaray energy. The response of a high purity germanium detector to xrays in the 815kev energy region has been investigated. Characterization of mechanically cooled high purity.
Determination of the photopeak detection efficiency of a hpge detector, for volume sources, via monte carlo simulations by raphael wesley damon dissertation submitted in fulfilment of the requirements for the master of science degree in physics at the university of the western cape july 2005 supervisors. When energy is deposited in the detector, the ipa detector converts the charge to a stepfunction output pulse of which. Keywords gammaray spectrometry, solid angle, efficiency, radioactive measurements 1. The crucial condition for hpge detector functioning properly is. The nitrospec is providing the complete range of functions and features which are offered by regular laboratory spectrometer based on hpge detectors but in a really miniature composition of all major. High purity germanium detectors hpge detectors are the best solution for precise gamma and xray spectroscopy. Modeling of bege detectors the detector used for the present simulation is a modified thickwindow version of a broad energy germanium bege detector 20, a standard ptype highpurity ge hpge detector offered by canberra semiconductor. Prompt gamma neutron activation pgnaa systems require the use of a gammaray spectrometer to record the gammaray spectrum of an object under test and allow the determination of the objects composition.
Highpurity germanium hpge gamma ray detectors have proven be essential for environmental, geological, and atmospheric research. Pdf high purity germanium koya4039 gamma detection system. The energy response function also was calculated using monte carlo. It is 90 mm in diameter and 10 mm thick with two sets of 16 orthogonal strips that have a 4. Osf autohpge, an autosampler for gammaray spectroscopy. General information on radioactivity and the measurement of radiation has been published 11 and 12. 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. Canberra models gc7020 old, from 1990, and gx6020 new, from.
To connect the diode to an electrical circuit to amplify the signal, we need to put. We present the working principles of a novel concept for gamma emission tomography using a segmented high purity germanium hpge detector. 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. Because high purity germanium detectors hpge has relatively low band gap, these detectors must be cooled down. Introduction the lbliucf collaborative program which suc cessfully developed high purity germanium chargedpar ticle detector systems to the point where their use at iucf could be considered routine was reported in our first paper 1. Pdf autohpge, an autosampler for gammaray spectroscopy.
Meng et alsizetunable germanium particles prepared by selfsustaining reduction of germanium oxide khachatur v. Demonstration of the event identification capabilities of the nextwhite detector. Highprecision efficiency calibration of a highpurity co. 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. Autohpge, an autosampler for gammaray spectroscopy using. Cooling system for the high purity germanium hpge detector in rn52 radionuclide monitoring station in tanay, philippines paolo tristan f.
The mirion high purity germanium hpge well detector provides maximum efficiency for small samples because the sample is virtually surrounded by active detector material. The crucial condition for hpge detector functioning properly is the low temperature 15 that allows the. Each detector type carries its own advantages and disadvantages, which is. The theory of response characteristics is explained, and the high resolution measurement results are contrasted with those from a sodium iodide nai. High purity germanium detectors stand out as the most commonly used solid state detector material, but other commonly used materials include sili 2 and cdznte cadmiumzinctelluride detectors. The best choice of high purity germanium hpge detector detector efficiencye the detector efficiency in eq. The work is broken down into three main contributions. Nuclear radiation detectors made from the crystals measure the betas from the.
The wvalue and energy resolution dependencies on the xray energy have been studied. In this configuration, the electric contacts are provided on the two flat surfaces of a germanium crystal. Detectors based on high purity germanium hpge are used in numerous experiments worldwide aiming at detecting rare events like double beta decay and. I have a question regarding gamma ray detector, the high purity germanium detector or aka hpge. Simulation of the response of a segmented highpurity. Fabrication and characterization of high purity germanium detectors with amorphous germanium contacts x. Snm shape can be determined by using a gamma ray imaging system that is capable of imaging either pu239 or u235.
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