The detectors from the hdm and igex experiments were reprocessed and used in phase 1. For this reason this report is a deliverable also in idea. Uptonow, their use in the xray energy range is less frequent, especially for energies lower than 20 kev, as the germanium dead layer is usually too thick to enable lowenergy photons to reach the crystal active volume. Planar configuration an example of a planar hpge detector using a ptype crystal is shown in fig.
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. 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. It is 90 mm in diameter and 10 mm thick with two sets of 16 orthogonal strips. In this case, however, it is advantageous to choose germanium rather than silicon as the detector material.
You will be able to diagram a gamma spectroscopy system and draw and explain principle components of a gamma spectrum. In this configuration, the electric contacts are provided on the two flat surfaces of a germanium crystal. When many atoms combine to form a solid, the valence shell has split. A highpurity germanium hpge detector is the ultimate instrument for energy spectrometry of gamma radiation.
The axial and radial distributions of impurities in the crystals were measured. The dependence of the energy resolution on the shaping parameter will be investigated. Learn more about ortecs high purity germanium radiation detectors hpge today. Most all of these detectors are used exclusively for. Abstractthe germanium detector array, gerda, will search for neutrinoless double beta decay in 76ge at the national gran sasso laboratory of the infn. Gammaray energies will be measured with a high purity germanium hpge detector and researchgrade electronics. Jun 01, 2015 highpurity germanium crystals approximately 12 cm in diameter were grown in a hydrogen atmosphere using the czochralski method. Digital pulse shape analysis is an encouraging approach to reduce the background originating from the latter. Performance of bare highpurity germanium detectors in. These detectors are made of high purity germanium hpge ptype and n, or silicon lithium sili. Nov 21, 2014 high purity germanium hpge detectors offer the best er of any conventional radiation detector with 1% fwhm at 140 kev johnson et al 2011a. Characterization of mechanically cooled high purity germanium.
A brief but very effective description on the basic formation. High purity germanium detectors are mostly used for gamma spectroscopy in nuclear physics, as well as xray spectroscopy. Use of a highpurity germanium semiconductor detector for. In nuclear physics we require precise knowledge of the energy and time of the interaction of a gammaray photon in a high purity germanium hpge detector. 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. 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. The electric and spectrometric characteristics of each individual segment and interactions between segments were investigated. For high purity germanium detectors, the fwhm of the 32. Demonstrated in gefica are generic numerical calculations based on the successive overrelaxation method as well as. Segmentation of pn junction was performed by implantation of boron for the ntype ge and mechanical grooving of the li diffusion layer for the ptype ge. Pdf large, highpurity, germanium hpge detectors are needed for neutrinoless doublebeta decay and dark matter experiments. Characterization of a highpurity germanium detector for.
Purest materials obtained are germanium ge rmanium detector 1 start with highpurity, ntype ge crystal. Segmented highpurity germanium detectors springerlink. Sep 16, 2011 a high purity germanium hpge detector is the ultimate instrument for energy spectrometry of gamma radiation. High purity germanium hpge detectors and spectrometers for gamma analysis, waste management, environmental monitoring, laboratory analysis, insitu measurements, homeland security, health physics, lowbackground measurements. Gamma background studies for the xenon experiment using a high purity germanium detector by jesse isaac angle may 2008 chair. Ptype point contact germanium detectors and their application in. It is 90 mm in diameter and 10 mm thick with two sets of 16 orthogonal strips that have a 4. Characterization of mechanically cooled high purity. Performance of bare highpurity germanium detectors in liquid argon for the gerda experiment m. Highpurity germanium hpge detectors offer the best er of any conventional radiation detector with 1% fwhm at 140 kev johnson et al 2011a. Nuclear recoil measurements with highpurity germanium detectors are very promising to directly detect dark matter candidates.
Some of the features that make silicon an excellent choice of material are the purity and the absence of dislocations, defects, and impurities. The methods are illustrated concretely with a new educational program named gefica germanium detector field calculator. Semiconductor detectors find broad application for radiation protection, gamma and xray spectrometry, and as particle detectors. 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. This summer student project involved the test and calibration of two high purity coaxial germanium gammaray detectors. Physics the xenon dark matter experiment, deploi 4 at the gran sasso national laboratory in italy on march 2006, is a liquid noble gas detector designed to directly detect dark matter.
What is meant by the detection efficiency at specific gammaray energy. The ultimate result of this analysis would be the deployment of this detector on an autonomous robot for sample collection and remote analysis. The germanium detector was calibrated with a 228 th source, the tof measurements with several delays from 2 ns up to 150 ns. Germanium well detectors are made from highpurity germanium and can therefore be shipped and stored at room temperature without harm. Optimization of amorphous germanium electrical contacts. The present disclosure provides a highpurity germanium hpge detector, comprising. Hpge detector field calculation methods demonstrated with an. These devices provide responders with more resolved spectra than detectors that use other materials. With an atomic number of 32, germanium has a much higher photoelectric cross section than silicon atomic. The energy resolution of the germanium detector was 1. We use both ptype and ntype germanium and we use diffused, implanted, and barrier contacts to achieve this product variety. High purity germanium hpge radiation detectors products. The advantages of position sensitivity coupled with the fine spectral resolution from high purity germanium can be exploited to produce a tracking detector for use with a variety of biochemically. 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.
Ortec provides a comprehensive suite of hpge radiation detector solutions covering an extensive range of energies and for a variety of 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 semiconductor detectors find broad application for radiation protection, gamma and xray spectrometry, and as particle detectors. Performance of bare highpurity germanium detectors in liquid. 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 printed circuit boards pcb containing the cooled electronics. 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. The calculation of electrostatic potentials and fields in a highpurity germanium hpge detector is the initial step in a full pulseshape simulation 1,2,3,4,5 process.
Introduction use of segmented highpurity germanium hpge detectors is foreseen in the gerda experiment germanium detector array 1,2 in the search of neutrinoless doublebeta decay of 76ge. 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. Topsil hps float zone silicon for detectors has the following unique. 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. In nuclear physics we require precise knowledge of the energy and time of the interaction of a gammaray photon in a highpurity germanium hpge detector. High purity germanium detector calibration at isolde. Introduction the lbliucf collaborative program which suc cessfully developed highpurity germanium chargedpar ticle detector systems to the point where their use at iucf could be considered routine was reported in our first paper 1. Position information has been limited to the solid angle and hence size. Gamma background studies for the xenon experiment using a. 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. Ssbi can offer the optimum detector for a wide range of applications. Pdf fabrication and characterization of highpurity germanium. 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 best choice of high purity germanium hpge detector detector efficiencye the detector efficiency in eq.
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. Curtolo, semiramis friedrich, bernd friedrich ime institute of process metallurgy and metal recycling, rwth aachen university, aachen, germany abstract since the early 1950s the use of germanium has been continuously growing. A cryogenic lownoise jfetcmos preamplifier for the hpge. To complete the gamma spectroscopy laboratory set caen sys includes in its offer a wide choice of high purity germanium detectors hpge. Unlike lithiumdrifted detectors, highpurity germanium detectors may be cycled repeatedly between ln 2 and room temperature with no compromise in performance. 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. However, these detectors require cooling to liquid nitrogen temperatures for optimal performance, making a compact imaging system for clinical and preclinical settings unrealistic in the past. Hpge detector field calculation methods demonstrated with. Comparison of a high purity germanium gamma ray spectrometer. High purity germanium detector in gammaray spectrometry. Both energy resolution and efficiency will be explored as a function of ray energy. The advantages of position sensitivity coupled with the fine spectral resolution from highpurity germanium can be exploited to produce a tracking detector for use with a. 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.
These detectors are made of highpurity germanium hpge ptype and n, or silicon lithium sili. On the underground production of high purity germanium detectors. Germanium detector how is germanium detector abbreviated. 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. High purity germanium detectors hpge detectors are the best solution for precise gamma and xray spectroscopy. Highpurity germanium hpge radiation detectors are well established as a valuable tool in. Purity germanium radiation detectors with amorphous. Digital gammaray spectroscopy with high purity germanium. Highpurity germanium crystals approximately 12 cm in diameter were grown in a hydrogen atmosphere using the czochralski method. Highpurity germanium detector ionization pulse shapes of nuclear recoils. Gammaray energies will be measured with a highpurity germanium hpge detector and researchgrade electronics. Detector fabrication and performance article pdf available in ieee transactions on nuclear science ns191. Simulation study comparing highpurity germanium and.
Highsensitivity detectors are portable devices that use highpurity germanium to provide highresolution gamma spectroscopy to identify radionuclides. The theory of response characteristics is explained, and the highresolution measurement results are contrasted with those from a sodium iodide nai. Gamma background studies for the xenon experiment using a high purity germanium detector by jesse isaac angle may 2008 ci v. Autohpge, an autosampler for gammaray spectroscopy using highpurity germanium hpge detectors and heavy shields. We present an initial evaluation of a mechanicallycooled, highpurity germanium doublesided strip detector as a potential gamma camera for smallanimal spect. High purity germanium detector calibration at isolde gu. Germanium detectors germanium short form catalog in pdf format j16 series detectors are highquality germanium photodiodes designed for the 800 to 1800nm wavelength range. Nuclear recoil measurements with high purity germanium detectors are very promising to directly detect dark matter candidates. Performance of the ultrahigh rate germanium uhrge system. Canberra models gc7020 old, from 1990, and gx6020 new, from.
On the underground production of high purity germanium. The canberra well detector is fabricated with a blind hole rather than a through hole, leaving at least 15 mm of active detector. The detector array is suspended in a liquid argon cryostat lined with copper and surrounded by an ultrapure water tank. The main background sources in such experiments are natural radioactivity and microphonic noise. Digital timing algorithm for high purity germanium detectors. The dislocation density of the crystals was determined to be in the range of 20004200 cm. Semiconductor detectors also can be used in gammaray spectroscopy. Simulation study comparing highpurity germanium and cadmium.
This was done by linearly combining every attenuated waveform with a pure noise waveform. Hpge tennessee research and creative exchange university of. The present disclosure provides a high purity germanium hpge detector, comprising. With an atomic number of 32, germanium has a much higher photoelectric cross section than. The first gamma ray spectrometer is the one dimensional high purity germanium spectrometer. This work investigates the ability of a highpurity germanium detector to perform postdetonation forensics on the debris from several types of nuclear weapons 24 hours after detonation. 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. For applications where temperature stability of response is important near the cutoff, thermoelectrically cooled detectors are available. This does not come better than in topsil high purity silicon hps. Highpurity germanium detector ionization pulse shapes of. We measured full energy peak efficiency of high purity germanium detector which is important for gammaray spectrometry experiments. Highpurity germanium hpge detectors and spectrometers for gamma analysis, waste management, environmental monitoring, laboratory analysis, insitu measurements, homeland security, health physics, lowbackground measurements.
It was clear that it was possible to merge the two deliverables since so many. Pdf autohpge, an autosampler for gammaray spectroscopy. Detectors based on high purity germanium hpge are used in numerous. Cea saclay detecslnhb 91191 gifsuryvette cedex, france. I have a question regarding gamma ray detector, the high purity germanium detector or aka hpge. Segmented planar highpurity germanium detectors were developed. The theory of response characteristics is explained, and the high resolution measurement results are contrasted with those from a sodium iodide nai. We measured full energy peak efficiency of highpurity germanium detector which is important for gammaray spectrometry experiments. Germanium well detector description the canberra highpurity germanium hpge well detector provides maximum efficiency for small samples because the sample is virtually surrounded by active detector material. The diameter and length of the neck joining the rdc to the cryostat vary. The experiment uses high purity enriched ge crystal diodes as a beta decay source and particle detector. It is also used to guide the design of novel detector geometries to avoid unreasonably high depletion voltages or hidden undepleted regions, which may occur when the size of a detector is enlarged. High purity germanium hpge detectors have been commonly used in gammaray spectrometry for many years.
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