Other articles where germanium detector is discussed. 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. Determination of natural radioactivity by gamma spectroscopy. Precise determination of uranium isotopes in suez canal. Influence of cell phone waves on the performance of hpge. High purity germanium hpge is the only radiation detection.
Energy and efficiency calibrations for high purity. Insitu object calibration software isocs technique for. This summer student project involved the test and calibration of two high purity coaxial germanium gammaray detectors. The full energy peak efficiency of a hyper pure germanium hpge detector. Projects nuclear science division nuclear science division. The collaboration predicts less than one event each year per kilogram of material, appearing as a narrow spike around the 0 qvalue. The detector is coupled to an ortec model 572a spectroscopy amplifier and an. The ge detector operated at near the temperature of liquid nitrogen to decrease the leakage current and hence the noise of the system. The calibration of hyper pure germanium detectors is required to calculate the activity of radioactive sources. 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. Hosted by journal of radiation research and applied sciences. A new hyperpure germanium hpge detector system for invivo measurements has been installed in the low background laboratory at the centre for radiation, chemical and environmental hazards of public health england, based at chilton. Hpge detector fullenergy peak efficiency calculation for.
Characterization of naturally occurring radioactive materials in libyan oil pipe scale using a germanium detector and monte carlo simulation author links open overlay panel a. In order to get secular, the samples were kept in the beaker for one month. With an atomic number of 32, germanium has a much higher photoelectric cross section than silicon atomic. Characterization of naturally occurring radioactive materials.
The use of hpge gamma rays detector for gross alpha and. Canberra models gc7020 old, from 1990, and gx6020 new, from. A cosmic muon veto system cmvs has been developed at ctbto headquarter to suppress muons induced background for a broad energy hyper pure germanium detector. Detailed specifications are available for j16 series room temperature detectors, parallel output arrays, avalanche photodiodes and two color detectors. Gamma and xray spectrometry with semiconductor detectors by. A study on the radioactivity level in raw materials, final. Gamma and xray spectrometry with semiconductor detectors. Germanium detectors germanium short form catalog in pdf format j16 series detectors are highquality germanium photodiodes designed for the 800 to 1800nm wavelength range. Initially samples were laid in the hpge detector, and then gamma spectrum was obtained as shown in figure 1. The gammaray spectrometry systemwith hyperpure germanium hpge detector has been used to determined radioactivity concentrations. In this paper, three distinctly different detector mechanicalcooler combinations were investigated. Evaluation of a detector system for measurement of low energy.
For simplification, these sources can be divided into three categories. The device and its electronic a hpge detector consists on a high purity germanium crystal directly connected to its. Trapping at the primary shallow donor is believed responsible for poor energy resolution at low temperatures. Lq nh9udqjh hpge virtual point detector for radioactive. Gamma spectrometer and relevant accessories were supplied by canberra, usa used to measure the activity concentrations for each radionuclide in the soil. The average value of full width at half maximum, fwhm, corresponds to the resolution of the high purity germanium hpge and sodium iodide. Abstract we present and evaluate a program for the semiempirical calculation of the fullenergy peak efficiency of a hyperpure germanium detector, by using the efficiency transfer method. Pdf energy and efficiency calibrations for high purity germanium. This video shows a brief demonstration of fulcrum and gegi germanium gammaray detectors manufactured by phds co. It uses large crystals of hyperpure germanium and is the first detector to use the concept of gammaray energy tracking. Pdf research and development in hpge detectors at lnl.
To determine the activity, the detector fullenergy. Naa laboratories operate one or more hyper pure or intrinsic germanium hpge detectors at. The project has been strongly motivated by a special production of germanium detectors for the gerda experiment. This is hyperpure metal when one considers that there are almost 1022 ge atomscm3 in solid germanium. A cylindrical leadshield of five cm thickness, which contains inner concentric thin cylinder of cu with a thickness of 5 mm, was used to shield the detector and to reduce the effect of background.
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. The concentration of uranium, thorium and potassium was measured for each variety of rice. 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. The activity concentrations of the sediment and black sand samples range from 4. Why high purity germanium hpge radiation detection. Mathematical model is used to estimate the activity concentrations of 222rn in the air with the activities of 226ra. 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. In this paper, three distinctly different detectormechanicalcooler combinations were investigated. Consult chapter 2, detector descriptions, for detailed descrip. Figure 1 illustrates the various detector geometries that are available from canberra, and the energy range they cover. These detectors are sensitive to light in the nir spectral region from 800 nm to 1800 nm. Characterization of naturally occurring radioactive materials in libyan oil pipe scale using a germanium detector and monte carlo simulation. The efficiency of hyper pure germanium hpge detector has been calculated by using a mathematical expression which derived in an integral form by mahmoud i. Fepe calibration of a hpge detector using radioactive sphere.
Experimental measurement of fullenergy peak efficiency. The sediment samples from the locations under this investigation were analyzed by alpha spectrometry for the precise determination of uranium and the isotopic ratios between 234u and 238u. Figure 2 depicts their significant performance characteristics. Thorlabs germaniumbased transimpedance amplified photodetectors feature a switchable gain setting housed in a compact, lowprofile package. A new digital filter has been investigated for removing lowfrequency periodic noise from the output signal of hyperpure germanium detectors hpge. In gammaray spectroscopy by hyper pure germanium detectors, one usually needs to know the photopeak efficiency for any specific source detector system. In the seventies high purity germanium detectors hpge or hyperpure ge. The use of hpge gamma rays detector for gross alpha and beta. The spectrometer consists of hyperpure germanium detector, electronic and recording devices. The system consists of five plastic scintillation plates operating in anticoincidence mode with the germanium detector. In this case, however, it is advantageous to choose germanium rather than silicon as the detector material. Evaluation of a detector system for measurement of low.
Hyper pure germanium detector for 36000 seconds 10 hours to acquire spectra data. Improvement of spectral resolution in the presence of periodic noise and microphonics for hyper pure germanium detector gamma ray spectrometry using a new digital filter. Low energy photon emitting radionuclides in the body j e scott abstract. Characterization of naturally occurring radioactive. Pdf fepe calibration of a hpge detector using radioactive. Resolution and efficiency of high purity germanium detector. The slim profile housing enables use in light paths with space const. Energy and efficiency calibrations for high purity germanium gem30195 coaxial detector using k 0. Marinelli, suited for hyper pure germanium hpge 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 semiconductor detectors find broad application for radiation protection, gamma and xray spectrometry, and as particle detectors.
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. Neutrinoless beta decay is expected to be a very rare process if it occurs. Naa laboratories operate one or more hyperpure or intrinsic germanium hpge detectors at. Helmer, gammaand xray spectrometry with semiconductor detectors, pp. Using simple montecarlo integration and constructive solid geometry, we are able to calculate the effective solid angle for a wide range of hpge detector. For photon spectroscopy in the energy region of hundred kev or several mev, much thicker semiconductor. In order to take benefit from their full capacities, one must connect them to state of the art signal processing spectroscopy amplifiers and acquisition boards. Jun 12, 20 the performance of a radiation shielding system for a hyper pure germanium detector has been characterised for terrestrial radiation sources, cosmic muons, xray fluorescence and the compton scattering of source photons. Determination of the volume efficiency of hyper pure germanium. In gammaray spectroscopy by hyper pure germanium detectors, one usually needs to know the photopeak efficiency for any specific sourcedetector system. Gretina is a new type of gammaray detector to study the structure and properties of atomic nuclei. When photons interact with the material within the depleted volume of a detector, charge carriers holes and electrons are produced and are swept by the electric. Hyper pure germanium detectors hpge are outstanding devices for radioactivity spectroscopy.
Measurement of the absolute efficiency of a semiconductor detector. Such detectors are commonly used in highresolution gammaray spectrometry, a technique vastly implemented in any advanced radio analytical laboratory or as part of comprehensive nuclear analytical methods. To determine the activity, the detector fullenergy peak photopeak efficiency is. Determination of the volume efficiency of hyper pure. Both energy resolution and efficiency will be explored as a function of ray energy. High purity germanium hpge radiation detectors products. The conventional coaxial germanium detector is often referred to as pure. The efficiency calibration of hpge detectors for volume source geometry has been discussed by many authors mahmoud, 2001 and 2007. Resolution, efficiency and stability of hpge detector. Several authors 111 have been treated the problem of the photopeak efficiencies determination and have given useful solutions. Determination of radium226 in rock samples by liquid. Measurement of natural radioactivity in aldora refinery. Hyperpure germanium hpge detectors are essential instruments in high. In this work, an ortec hyper pure germanium gamma ray spectrometer was used.
The use of high purity germanium detectors hpge has been planned. Efficiency and resolution of hpge and naitl detectors using. Values from the measured activity concentration can be used to characterise the radiological risk associated with these sample locations. Operation near liquid helium temperature of a gold.
The samples were analyzed by gamma ray spectrometry technique using a hyperpure germanium hpge detector of 40% relative efficiency. Montecarlo based background reduction and shielding. Ortec provides a comprehensive suite of hpge radiation detector solutions covering an extensive range of energies and for a variety of applications. When photons interact with the material within the depleted volume of a. Techniques have been developed to achieve high purity ge crystals in this approach and hyperpure ge hpge detectors are commercially. Otherwise, leakage current induced noise destroys the energy resolution of the detector. Improvement of spectral resolution in the presence of. Hyper pure germanium spectroscopy faster usecase n5 page 3 from 11 jm. Energy and efficiency calibrations for high purity germanium. Measurement of natural radioactivity in aldora refinery by. Canberra makes a wide variety of detector types which are described in this instruction manual. High purity germanium detector calibration at isolde gu. Mar 22, 2018 this video shows a brief demonstration of fulcrum and gegi germanium gammaray detectors manufactured by phds co.
The conventional coaxial germanium detector is often referred to as pure ge, hpge. Diode characteristics and spectral response to 7cs. Semiconductor detectors find broad application for radiation protection, gamma and xray spectrometry, and as particle detectors. Request pdf measuring radioactivity level in various types of rice using hyper pure germanium hpge detector the radioisotopes and nuclear explosions in. A hyper pure germanium hpge system is tailored for measuring low activity samples. Several methods to reduce the background seen are quantified, including increasing the inner radius of the pb cave, and increasing the thickness of the shielding. 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.
The samples were analyzed by gamma ray spectrometry technique using a hyper pure germanium hpge detector of 40% relative efficiency. Semi conductor detectors medusa wiki the medusa institute. Preset counting time of 30,000s was used for each sample to avoid statistical errors. For applications where temperature stability of response is important near the cutoff, thermoelectrically cooled detectors are available. Sources of noise examined include microphonics and simulated lowfrequency noise via input sinusoidal wave forms. The search for double beta decay with germanium detectors. A cosmic muon veto system cmvs has been developed at ctbto headquarter to suppress muons induced background for a broad energy hyperpure germanium detector. The gedetector operated at near the temperature of liquid nitrogen to decrease the leakage current and hence the noise of the system. Results showed the activities varied from one site to another. It is built from large crystals of hyper pure germanium and will be the first detector to use the recently developed concept of gammaray energy tracking.
Standard electrode coaxial ge detectors sege gammadata. A new hyper pure germanium hpge detector system for invivo measurements has been installed in the low background laboratory at the centre for radiation, chemical and environmental hazards of public health england, based at chilton. A new digital filter has been investigated for removing lowfrequency periodic noise from the output signal of hyper pure germanium detectors hpge. Each sample was identified for the radionuclide that is. It is built from large crystals of hyperpure germanium and will be the first detector to use the recently developed concept of gammaray energy tracking. The dependence of the energy resolution on the shaping parameter will be investigated. The performance of a radiation shielding system for a hyperpure germanium detector has been characterised for terrestrial radiation sources, cosmic muons, xray fluorescence and the compton scattering of source photons. Therefore, the count rate from background sources as building materials and cosmic rays is reduced by a castle of old lead placed around the detector. Hyperpure germanium hpge is the most common solid state detector for high resolution gamma ray spectroscopy. Moreover, normal soil and natural surface water samples from the suitable areas adjacent to the factories were also collected for the comparison purpose. Abstract we present and evaluate a program for the semiempirical calculation of the fullenergy peak efficiency of a hyper pure germanium detector, by using the efficiency transfer method. Under reverse bias, an electric field extends across the intrinsic or depleted region. Water sampling calibration in energy kev calibration in concentration ppm.
Precise determination of uranium isotopes in suez canal sediment. Improvement of spectral resolution in the presence of periodic noise and microphonics for hyper pure germanium detector gammaray spectrometry using a new digital filter. Measuring radioactivity level in various types of rice. It consists of a cylindershaped n type germanium crystal, touching on the outside and kind of touching on the surface of the p axis. Learn more about ortecs high purity germanium radiation detectors hpge today. The sediment samples from the locations under this investigation were analyzed by alpha spectrometry for the precise determination of uranium and the isotopic ratios between 234u. The activity concentrations of the uraniumseries were determined using. High purity germanium detector calibration at isolde.
Operation near liquid helium temperature of a goldbarrier hyperpure germanium detector for gammarays. For applications where temperature stability of response is important near. The spectrometer consists of hyper pure germanium detector, electronic and recording devices. Hyper pure germanium detectors semiconductor crystal detectors are used without any added impurity. Samples were put in a closed plastic container for one month to fulfil the radioactive equilibrium. The activities of 226 ra and 232 th are much higher than the recommended average limit given. For the two radionuclides of interest 85kr and 3xe, the main contributions to the total uncertainty in the activity measurements are the. Experimental measurement of fullenergy peak efficiency and. The ptype hpge detector supplied by ortec modelgem2070. This book covers the topics essential to gamma and xray spectrometry as it is. Liquid scintillation counter the quantulus 1220 scintillation counter manufactured by wallac, supported. Semiconductor detectors also can be used in gammaray spectroscopy. The correct energy resolution of hpge detector is 1.
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