The photopeak efficiency was studied at the geometry with the source to detector distance of 5 cm, 10 cm, 15 cm and 20 cm. Comparing hpge and scintillator detectors for gamma. Druker2, 1horia hulubei national institute of physics and nuclear engineering ifinhh, bucharestmagurele, pob mg6. Hpge detector that enables ultralow detection limits in these applications. Cryogenic cooling is required for germanium semiconductor radiation detectors. The majority of gamma spectroscopy applications such as those found in counting. Gem series coaxial hpge detector product configuration guide streamline cryostat and cryostatdewar assemblies streamline systems detector capsule and cryostat share the same vacuum, requiring a cryostat or cryostatdewar selection with the cryostat having a matching diameter to the capsule endcap.
The hgi2 detector did not have sufficient efficiency or resolution to distinguish between. High purity germanium hpge detectors are acknowledged as the gold standard detector for radioisotope identification because they provide 35 times better in energy resolution selectivity than sodium iodide and 15 times better in resolution than labr, cebr, or sri. A set of time aligned signals was acquired in a coincidence measurement using a coaxial hpge and a ceriumdoped lanthanum chloride lacl 3. Full energy peak efficiency calibration of hpge detector. Hpge detectors with extended energy range gcdx provide outstanding performance not only as regular coaxial detectors but also allowing to go lower in energy range down to 3 kev. Ortec detective x hpge radioisotope identification device.
Introduction high purity germanium hpge detectors 1 are. Hpge detector efficiency calibration for extended sources. The germanium detector array or gerda experiment is searching for neutrinoless double beta decay 0 in ge76 at the underground laboratori nazionali del gran sasso lngs. Is it the hpge ntype detector externe dead layer existing. The concept of double points detector model approach dpdm is developed as a procedure to find the full energy peak efficiency of the coaxial 120 cm 3 closed hyperpure germanium hpge detectors. The diameter and length of the neck joining the rdc to the. Hpge detectors timing using pulse shape analysis techniques. Liquid nitrogen ln 2 or electromechanical cooling system are both available. How should i recool this hpge detector that has warmed up. You will also compare the performance of a naitl scintillation detector with that. Also, the hpge detector offers very good resolution. This is unlike the older lithium drifted detectors that were not tolerant of any significant warm up because of the associated migration of the lithium ions, resulting in an improperly functioning detector.
Selecting a detector all itech hpge and sili detectors can be temperature cycled and stored indefinitely at room temperature. The results show that neither of the detectors was ideally capable of supporting dtras requirements. Characterization and performance of a hpge detector for nuclear materials verification m. The automated hpge spectrometer is a fully automated systems with a robotic sample changer enabling the user to measure up to 40 samples, without having to interact with the automated spectrometer. 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. Germanium detectors allow for an accurate detection of complex. Resolution function of a gmx series coaxial detector system model number gmx40p483 in the range of 40 kev to 1. Weak alpha sources available without a specific nrc. Efficiency calibration of hpge gamma spectrometry of lan.
Gem series coaxial hpge detector product configuration guide. Thin contact structure of the hpge detector accompanying with input window made of beryllium or carbon fiber guarantee low energy photon transition to the hpge crystal. 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. Gammaray spectrometry using naitl and hpge detectors. This data, which may be trended over time, allows the user to take preventative. A highpurity germanium hpge detector is the ultimate instrument for energy spectrometry of gamma radiation. Two daq systems based on digital signal analysis were used.
Semiconductor detector an overview sciencedirect topics. Precise efficiency calibration of an hpge detector. Usually in the experimental nuclear physics work, which involves using hpge detector for gammaray spectrometry, the full energy peak efficiency function must represent adequately the hpge detector. This shielding system was manufactured in our laboratory at the ubb clujnapoca. Efficiency and resolution of hpge and naitl detectors using. In so called streamline systems, the detector capsule in not demountable. Introduction the aim of this paper is to present the use of a high purity germanium gammaray detector hpge in an underground counting room at saclay near paris, france, along with a montecarlo simulation and analysis software suite.
Monte carlo techniques are used to calculate the full energy peak values of the hpge detector radius r d, length t d for photons were obtained for point source. The use of high purity germanium hpge type detectors have the great advantage that they can be allowed to warm up and not suffer damage. Analyzing the background count showed a large amount of ambient radiation. When many atoms combine to form a solid, the valence shell has split. Experimental efficiency calibration of a hpge detector 100 cm 3 for a point source at 12 cm between 10 and 1500 kev linear scale energy kev 0 200 400 600 800 1200 1400 1600 1800 efficiency % 0. The standard coaxial ptype detector serves for measurement of gammaradiation having energies between approx. Singh 1 1inter university accelerator center, new delhi 110067 2department of physics and astrophysics, universit y of delhi, new delhi 17 e mail address. Determination of full energy peak efficiency of hpge. 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. For photon spectroscopy in the energy region of hundred kev or several mev, much thicker semiconductor. Full energy peak efficiency calibration of hpge detector by mcnp 5. The essence of a poptop detector system is that the hpge detector element cryostat, preamplifier, and high voltage filter are housed in a detector capsule which is then attached to an appropriate cryostat figure 2. This experiment will familiarize you with the instrumentation used in gammaray spectrometry and with the quantitative aspects of gamma counting. Several parameters are useful in the selection of a detector for a particular application.
The resolution of hpge detector gc2018, diameter 60. All of their features, including photopeaks, summation peaks, annihilation peaks, and xrays were indenti. Gem series coaxial hpge detector product configuration guide ptype coaxial hpge detectors for high performance gamma spectroscopy in the energy range of 40 kev and up. Standard cryostat uses molecular sieve pumping agent. It is shown that full energy peak efficiency decreases with increases in gamma ray energy. Neutrinoless beta decay is expected to be a very rare process if it occurs. The energy and fwhm calibration of a gamma spectrometric system with a hpge detector on the basis of the background spectrum m.
On the underground production of high purity germanium. Calculation of full energy peak efficiency for hpge. Gammaray efficiency of a hpge detector as a function of. A bias voltage of 1500v is applied to the detector. Hpge detector were performed in order to determine the parameters of anisotropic mobility for. 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. Computation of the full energy peak efficiency of an hpge detector 625 journal of engineering science and technology october 20, vol.
Hpge detector field calculation methods demonstrated with. Germanium hpge detector detector efficiencye the detector efficiency in eq. Gaussian energy broadening function of an hpge detector in. This is understandable given that the main application of simion is not hpge detector. I mm length hpge ortec detector, model gem15190 which has about 90 cm3 active volume. Determination of the photopeak detection efficiency of a. Evaluation of cooling technologies for hpge detectors. 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. Studying of characteristics of the hpge detector for. The hpge detector is an dsg planar high purity germanium crystal with a diameter of 16mm, a length of 10mm, a beryllium window of 0. Although we had talented technicians who became very proficient at production and orren was able to keep cryostat design at a competitive level, we had no one on the staff doing device development. Hpge gamma detector is used for analysis environmental samples in which calibration is very important. Pdf hpge detectors long time behaviour in highresolution.
Full energy peak efficiency of hpge detector 283 2 00 2 2 00 sin sin i wholesolidangle d dd q d dd. Detector and data acquisition daq system located in a room behind the pool wall that allowed for easy exchange of various detectors see 5,6 for geometrical setup details. Detection of special nuclear material with high purity. Ortec provides a comprehensive suite of hpge detector solutions covering an extensive range of energies and for a variety of applications. Evaluation of cooling technologies for hpge detectors joel forrester1, james colaresi 2, herbert gohla3, ethan hull4, michael pickering5, george rybicki6, george shipman5, robert werzi3, michael yocum2 1 pacific northwest national laboratory, 2 canberra industries, 3 provisional technical secretariat, ctbto, 4 phds co. Highpurity germanium hpge detectors are widely used in nuclear spectroscopy e. This leads to many types of hpge detectors which are suitable for different applications or special research options. Characterization of a 109cd gammaray source for the twophase. The collaboration predicts less than one event each year per kilogram of material, appearing as a narrow spike around the 0 qvalue. The printed circuit boards pcb containing the cooled electronics.
For natural samples with a very low activity it is difficult to separate the. Specification for hpge detector and accessories the items should be complete with all required accessories as per the detailed specification mentioned below. If the source is far from the detector, the gamma spectrum analysis software now. The high purity germanium detectors hpge complete set is composed by the following components. Gammaray spectrometry using naitl and hpge detectors objectives. Using the hpge detector in tandem with the mca, all of the spectra were measured. Hpge detector, gamma spectrometry, low background, montecarlo simulation, photomultiplier tube. Design and setup of a new hpge detector based body counter. Box 7551, nasr city, 11762 cairo, egypt b physics dept. Relative probability of each of the three types of interactions as a function of energy. Geli was later replaced with more advanced, high purity germanium hpge detectors. It needs large amount of labor power, comparatively long time and rich experience. Pdf a large set of data on long term performance of ntype hpge detectors used in gasp, euroball and clara.
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. The electronic system includes a spectroscopy amplifier with pileup rejection. A large hpge detector for the nondestructive radioassay. The picture of the hpge detector and diagram of the experimental setup are shown in. To approach this goal, we have used highstatistics spectra from seven well known radionuclides, including a 60co source whose absolute activity is known to 0. Pdf the photopeak efficiency, the peak to valley ratio, the energy resolution and the minimum detectable activity of a hpge detector were. Detectors based on high purity germanium hpge are used in numerous experiments worldwide aiming at detecting rare events like double beta decay and interactions of dark matter see e. Canberra found success in geli detector manufacturing by making refinements to the basic processes that fiedler brought with him. And the azimuthal angle is sampled by the equation.
The radiation detected can be attributed to shortlived excited states of the product. The spectrometers are used for radionuclide analysis and for monitoring of activity in the nuclear industry and related environment monitoring. Because high purity germanium detectors hpge has relatively low band gap, these detectors must be cooled down. A compute program has been written to carry out their calculations and it can use for different sizes and types of gamma detectors. Pdf studying of characteristics of the hpge detector for. 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. An integrated digital backend makes use of the detector sensors to continuously monitor and store all relevant parameters and status information.
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