Canberra found success in geli detector manufacturing by making refinements to the basic processes that fiedler brought with him. Resolution function of a gmx series coaxial detector system model number gmx40p483 in the range of 40 kev to 1. 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. Ortec detective x hpge radioisotope identification device. 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. Precise efficiency calibration of an hpge detector. 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. Also, the hpge detector offers very good resolution.
Characterization of a 109cd gammaray source for the twophase. Gaussian energy broadening function of an hpge detector in. 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. 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. Gammaray spectrometry using naitl and hpge detectors objectives. 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. 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. Full energy peak efficiency calibration of hpge detector by mcnp 5. It needs large amount of labor power, comparatively long time and rich experience. The collaboration predicts less than one event each year per kilogram of material, appearing as a narrow spike around the 0 qvalue.
This reliable robotic sample changer increases the productivity and reduces the possibility of health risks hpge systems hpge all in one. Neutrinoless beta decay is expected to be a very rare process if it occurs. 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. The majority of gamma spectroscopy applications such as those found in counting. Specification for hpge detector and accessories the items should be complete with all required accessories as per the detailed specification mentioned below. The hgi2 detector did not have sufficient efficiency or resolution to distinguish between. You will also compare the performance of a naitl scintillation detector with that. 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. 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. To date, however, they have had limited effect on nuclear medicine. Calculation of full energy peak efficiency for hpge.
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. For natural samples with a very low activity it is difficult to separate the. The resolution of hpge detector gc2018, diameter 60. Gem series coaxial hpge detector product configuration guide. The energy and fwhm calibration of a gamma spectrometric system with a hpge detector on the basis of the background spectrum m. Hpge detector were performed in order to determine the parameters of anisotropic mobility for. Singh 1 1inter university accelerator center, new delhi 110067 2department of physics and astrophysics, universit y of delhi, new delhi 17 e mail address.
A compute program has been written to carry out their calculations and it can use for different sizes and types of gamma detectors. Detection of special nuclear material with high purity. The photopeak efficiency was studied at the geometry with the source to detector distance of 5 cm, 10 cm, 15 cm and 20 cm. Semiconductor detector an overview sciencedirect topics. 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. 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. 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. This shielding system was manufactured in our laboratory at the ubb clujnapoca.
Determination of full energy peak efficiency of hpge. 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. On the underground production of high purity germanium. This data, which may be trended over time, allows the user to take preventative. The electronic system includes a spectroscopy amplifier with pileup rejection. Analyzing the background count showed a large amount of ambient radiation. Computation of the full energy peak efficiency of an hpge detector 625 journal of engineering science and technology october 20, vol. Is it the hpge ntype detector externe dead layer existing. The second area of detector performance evaluated was the emc hpge detectors cooling capabilities and its effect on the performance of the detector. An integrated digital backend makes use of the detector sensors to continuously monitor and store all relevant parameters and status information. 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. How should i recool this hpge detector that has warmed up. In so called streamline systems, the detector capsule in not demountable.
The picture of the hpge detector and diagram of the experimental setup are shown in. If the source is far from the detector, the gamma spectrum analysis software now. It is shown that full energy peak efficiency decreases with increases in gamma ray energy. 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. A large hpge detector for the nondestructive radioassay. Hpge detector field calculation methods demonstrated with. This experiment will familiarize you with the instrumentation used in gammaray spectrometry and with the quantitative aspects of gamma counting. 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. 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. Portable hpge detector is designed for detection, accumulation and processing of gamma spectra in field and industry conditions where small dimensions and weight of spectrometer are important. Hpge detectors timing using pulse shape analysis techniques. Efficiency calibration of hpge gamma spectrometry of lan.
Liquid nitrogen ln 2 or electromechanical cooling system are both available. Highpurity germanium hpge detectors are widely used in nuclear spectroscopy e. The diameter and length of the neck joining the rdc to the. 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 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. All of their features, including photopeaks, summation peaks, annihilation peaks, and xrays were indenti.
The high purity germanium detectors hpge complete set is composed by the following components. The radiation detected can be attributed to shortlived excited states of the product. Germanium detectors allow for an accurate detection of complex. Hpge detector efficiency calibration for extended sources.
Weak alpha sources available without a specific nrc. Evaluation of cooling technologies for hpge detectors. Cryogenic cooling is required for germanium semiconductor radiation detectors. 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. This leads to many types of hpge detectors which are suitable for different applications or special research options. A highpurity germanium hpge detector is the ultimate instrument for energy spectrometry of gamma radiation.
Ortec provides a comprehensive suite of hpge detector solutions covering an extensive range of energies and for a variety of applications. 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. 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. Selecting a detector all itech hpge and sili detectors can be temperature cycled and stored indefinitely at room temperature. 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. So it can generate current called leakage current at room temperature. 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. Two daq systems based on digital signal analysis were used.
Hpge detector that enables ultralow detection limits in these applications. The energy response function also was calculated using monte carlo simulation. Comparing hpge and scintillator detectors for gamma. Germanium hpge detector detector efficiencye the detector efficiency in eq. I mm length hpge ortec detector, model gem15190 which has about 90 cm3 active volume. For photon spectroscopy in the energy region of hundred kev or several mev, much thicker semiconductor. The results show that neither of the detectors was ideally capable of supporting dtras requirements. The printed circuit boards pcb containing the cooled electronics. 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. Using the hpge detector in tandem with the mca, all of the spectra were measured. Druker2, 1horia hulubei national institute of physics and nuclear engineering ifinhh, bucharestmagurele, pob mg6. Determination of the photopeak detection efficiency of a.
Hpge detectors abstract in this work the pulse shape analysis has been used to improve the time resolution of high purity germanium hpge detectors. Several parameters are useful in the selection of a detector for a particular application. Studying of characteristics of the hpge detector for. The standard coaxial ptype detector serves for measurement of gammaradiation having energies between approx. 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. Pdf the photopeak efficiency, the peak to valley ratio, the energy resolution and the minimum detectable activity of a hpge detector were. Efficiency and resolution of hpge and naitl detectors using. Pdf a large set of data on long term performance of ntype hpge detectors used in gasp, euroball and clara. Box 7551, nasr city, 11762 cairo, egypt b physics dept. 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. Because high purity germanium detectors hpge has relatively low band gap, these detectors must be cooled down.
This is understandable given that the main application of simion is not hpge detector. Standard cryostat uses molecular sieve pumping agent. And the azimuthal angle is sampled by the equation. Gammaray efficiency of a hpge detector as a function of. Full energy peak efficiency of hpge detector 283 2 00 2 2 00 sin sin i wholesolidangle d dd q d dd. Pdf hpge detectors long time behaviour in highresolution.
A bias voltage of 1500v is applied to the detector. Design and setup of a new hpge detector based body counter. Relative probability of each of the three types of interactions as a function of energy. The spectrometers are used for radionuclide analysis and for monitoring of activity in the nuclear industry and related environment monitoring. Characterization and performance of a hpge detector for nuclear materials verification m. Hpge detector, gamma spectrometry, low background, montecarlo simulation, photomultiplier tube. Introduction high purity germanium hpge detectors 1 are.
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