A method to improve the efficiency of photon collection in thin planar HPGe detectors was investigated. The method involved implementing a second HPGe detector to collect Compton scattered photons from the primary detector and incorporating coincident int...
National Technical Information Service (NTIS)
Interest in reducing the labor-intensive requirements for calibrating HPGe detectors has resulted in various efficiency models. The present study examines a method for predicting the efficiencies over ranges of sample geometries, whereby only a few measur...
Interest in reducing the labor-intensive requirements for calibrating HPGe detectors has resulted in various efficiency models. The present study examines a method for predicting the efficiencies over ranges of sample geometries, whereby only a few measurements are required. The method has been appraised against ...
Energy Citations Database
The concept of a virtual point detector (VPD) has been developed and validated in the past for Ge(Li) and HPGe detectors. In the present research, a new semi-empirical equation involving photon energy and source-virtual point detector distance for the efficiency of point sources by ...
PubMed
Efficiency calibrations of multiple high-purity germanium (HPGe) detectors are being maintained at the National Institute of Standards and Technology (NIST). Four generally available software packages for HPGe detector gamma-ray spectrum analysis, including the one currently used at NIST, were ...
The absolute efficiency of a high purity germanium (HPGe) detector was determined with a point-like calibrated sup 1 sup 5 sup 2 Eu source at two distances from the detector and three pure metallic thorium foils of different thicknesses. The experimental values are compared with the ones determined with the ...
E-print Network
Interest in reducing the labor-intensive requirements for calibrating high-purity germanium (HPGe) detectors has resulted in various efficiency models. This study examines a method for predicting the efficiencies over ranges of sample geometries, whereby only a few measurements are required. The method has been ...
A new method is proposed for the problem of solving chi-square minimization with a positive solution. This method is embodied in an evolution of the popular NNLS algorithm. Its efficiency with respect to residue minimization is illustrated by the improvement it permits on the location of gamma-interactions inside an AGATA HPGe ...
NASA Astrophysics Data System (ADS)
Aim of this work is to study the effect of various simulation parameters on the calculation of the full energy peak efficiency of HPGe detectors with the Monte Carlo simulation code PENELOPE. PMID:19954990
Measurements in prompt gamma neutron activation analysis (PGNAA) typically have errors of the order of {+-}2 to 3%. A method is described that can yield a lower limit on the uncertainty in relative efficiencies applied to PGNAA of about {+-}0.1%.
A new generation of high-resolution hypernuclear ?-spectroscopy experiments with high-purity germanium detectors (HPGe) are presently designed at the FINUDA spectrometer at DA?NE, the Frascati ?-factory, and at P�ANDA, the p�p hadron spectrometer at the future FAIR facility. Both, the FINUDA and P�ANDA spectrometers are built around the target region ...
Numerical expressions to compute gamma-gamma and gamma-X(K) coincidence summing corrections were deduced by using a suitable computer program and a matrix representation of a decay scheme. For point sources only full-energy peak and total efficiencies are needed. Alternatively, values of peak-to-total ratio can be introduced. For extended sources, the same expressions can be ...
Gamma spectroscopists often must analyze samples with geometries for which their detectors are not calibrated. The effort to experimentally recalibrate a detector for a new geometry can be quite time consuming, causing delay in reporting useful results. Such concerns have motivated development of a method for extrapolating high-purity germanium ...
Abstract: The Multi-sensor Airborne Radiation Survey (MARS) project has developed a new single cryostat detector array design for high purity germanium (HPGe) gamma ray spectrometers that achieves the high detection efficiency required for stand-off detection and actionable characterization of radiological threats. This approach is ...
Isomer decays, {beta}-{gamma} and electron-{gamma} spectroscopy, {alpha}-{gamma} fine structure studies, and Coulomb excitation are cases of nuclear structure experiments where the ideal detector is a compact, highly segmented, very efficient germanium (Ge) detector box. In order to develop such a structure, we are working on the ...
DOE Information Bridge
Equations to compute ??? and ??XK coincidence-summing corrections in gamma-ray spectrometry with p-type HPGe detectors are reported. For point sources only full-energy-peak and total efficiencies are needed.
The Monte Carlo method was used to calculate the efficiency, escape and Compton curves of a planar high-purity germanium detector (HPGe) in the 20-150 keV energy. These curves were used for the determination of photons spectra produced by an X-ray machine in order to allow a precise characterization of photon beams applied to medical ...
We present the use of a low background counting facility, equipped with a p-type 80% relative efficiency HPGe detector, protected by active and passive shielding, and large enough to count a 10 in photo-multiplier tube (PMT). A GEANT4 Monte-Carlo of this detector was developed and tuned to 3% accuracy. We report ...
The Kimballton Underground Research Facility (KURF) is home to several experiments. One consists to two HPGe detectors designed to screen candidate materials to be used in low-background experiments for radioactivity. Analysis techniques, including our efficiency calculations will be presented. We have also deployed a customized BEGe ...
Quantitative Anger-camera tomography requires correction for Compton scattering. The Anger camera spectral-fitting technique can measure scatter fractions at designated positions in an image allowing for correction. To permit verification of those measurements for {sup 131}I, the authors have determined scatter fractions with a high-purity germanium (HPGe) ...
We have successfully developed and fielded an electromechanically cooled germanium radiation detector (EMC-HPGe) at Lawrence Livermore National Laboratory (LLNL). This detector system was designed to provide optimum energy resolution, long lifetime, and extremely reliable operation for unattended and portable applications. For most ...
The knowledge of the full-energy peak efficiency for a specific source-detector arrangement is often required in various fields of research and applications, such as the analysis of nuclear waste or environmental samples, where both require modeling because it is not practical to prepare a standard that matches the physical and nuclear properties of every ...
The relative efficiency up to 9.7 MeV was calibrated for two coaxial detectors, one Ge(Li) and one high purity Ge. The efficiency curves were determined by using a combination of standard radioactive sources and (n,..gamma..) reactions. Based on the result of this work, the general slope of the two detector ...
The code PENELOPE is applied here to the efficiency calibration exercise described in the EUROMET project 428 [L�py et al., 2001. Appl. Radiat. Isot. 55, 493]. We evaluated the peak efficiencies for a coaxial HPGe detector in the range 60-2000 keV, for point sources located at various distances from the ...
Instead of conventional human counter using NaI(Tl) scintillator in scanning bed geometry, integrated whole body counter was developed. This is constituted by 10 detectors that are located just above the objective organs in order to improve the identification of nuclides. Two sets of p-type arrayed planar HPGe detectors composed of two ...
Previously we used relative and absolute efficiency measurements combined with Monte Carlo calculations to define the efficiency of an HPGe gamma-ray detector with 0.2% accuracy from 50 to 1400 keV. This work has been extended to 4.8 MeV with measurements of relative efficiencies from 24Na, ...
Traditional ways of determining the absolute full-energy peak efficiencies of high-purity germanium (HPGe) detectors are often time consuming, cost prohibitive, or not feasible. A software package, KMESS (Kevin's Mesh Efficiency Simulator Software), was developed to assist in predicting these ...
High-purity germanium (HPGe) detectors used in space for gamma-ray spectroscopy in astrophysics and planetary exploration are known to be damaged by energetic particles. For interplanetary missions close to the Sun such as Messenger or BepiColombo to explore planet Mercury, solar protons represent an important source of damage. In this work, irradiation ...
In this work several mathematical functions are compared in order to perform the full-energy peak efficiency calibration of HPGe detectors using a 126cm HPGe coaxial detector and gamma-ray energies ranging from 36 to 1460 keV. Statistical tests and Monte Carlo simulations were used to study the ...
We report on the first experimental demonstration of Compton imaging of gamma rays with a single coaxial high-purity germanium (HPGe) detector. This imaging capability is realized by two-dimensional segmentation of the outside contact in combination with digital pulse-shape analysis, which enables to image gamma rays in 4{pi} without employing a ...
A HPGe detector incorporated into a Compton suppression and pair spectrometer yields a continuum suppression factor of over 30. Cryostat housing requirements to obtain such suppression are discussed, sample spectra are presented, and several experiments making use of the HPGe dual system are discussed.
The detector system is based on a HpGe detector with an efficiency of 27%, surrounded by a NaI(Tl) crystal of 11.03 cm sup 3 and the electronic chain with a coincidence unit. The peak to Compton edge ratio is about 550, and the maximum Compton continuum s...
Most high-efficiency interactions for neutron detection are with thermal neutrons, and the detection of the prompt gamma radiation emitted as a result of thermal neutron absorption in specific materials was sometimes used. These materials are named converters, the most widespread being 10B, 113Cd or 73Ge (the last two materials are detector materials ...
Underwater NAI(Tl) and HPGe detectors are used in the environmental measurements programs at the Savannah River Site (SRS). A 22.9 cm {times} 10.2 cm NAI(Tl) detector on the Savannah River continuously monitors effluent releases from both SRS (DOE) and Plant Vogtle (Georgia Power). Correlations with known releases indicate a ...
A large set of data on long term performance of n-type HPGe detectors used in GASP, EUROBALL and CLARA ? spectrometers, as well as environmental measurements have been collected over two decades. In this paper a detailed statistical analysis of this data is given and detector long term behaviour is provided to the scientific community. ...
A method is presented whereby the intrinsic efficiency of Ge is utilized to calculate the expected peak efficiency of detectors having a wide range of sizes. The intrinsic efficiency of Ge, which is the probability for total absorption, was measured at 122 and 136 keV in Ge(Li) coaxial ...
We describe the use of the Los Alamos FRAM isotopic analysis software to make the first reported measurements on thick-walled UF{sub 6} cylinders using small planar HPGe detectors of the type in common use at the IAEA. Heretofore, planar detector isotopic analysis measurements on uranium have used the 100-keV region and can be defeated ...
The optimum condition of three commonly used functions in the Genie 2000 ? spectra analysis software have been studied in the 121-1408 keV energy range. The three functions are applied for fitting the full-energy peak efficiency of the HPGe gamma-ray detector. A detailed procedure to obtain the optimum condition is described. The ...
A personal-computer-based program SWELL has been developed for well-type HPGe detector effective-solid-angle calculation. This program is very useful in constructing the absolute-peak efficiency (?p) versus ?-ray energy (E?) curves for different sample geometries based on a pre-determined ?p under a reference counting geometry. The ...
By comparing the pulse shapes, using pulse shape analysis (PSA), the interaction positions within a position sensitive HPGe crystal can be accurately located. Compton Image Reconstruction can be used to create an image testing the accuracy of the ability to locate the positions of scatter and absorption events, through PSA. The more accurately the points of interaction are ...
Precise beta-branching-ratio measurements are required in order to determine ft-values as a part of our program to test the Electroweak Standard Model via unitarity of the Cabibbo-Kobayashi-Moskawa matrix. For the measurements to be useful in this test, their precision must be close to 0.1 %. In a branching-ratio measurement, we position the radioactive sample between a thin plastic scintillator ...
This work deals with most significant sources of uncertainty in determination of radionuclides massic activity in 200 L drums with radioactive waste (RAW) from decommissioning of nuclear power plant (NPP) A1 and operational air cleaning filters coming from different parts of NPP's ventilation system. It turned out that the most significant source of uncertainty is determination of photo peak ...
Measurement of the enrichment of solid state UF6 stored within large metal cylinders is a task commonly performed by plant operators and inspectors. The measurement technologies typically used range from low-resolution, high-efficiency sodium iodide detectors to high-resolution, moderate-efficiency high-purity germanium ...
We present position sensitivity measurements obtained with one of the 32-fold segmented HPGe detectors from Michigan State University. These measurements were performed with a collimated beam of 137Cs gamma rays scattered by 90 degrees. This deposits 374 ...
Savannah River Site (SRS) effluent gamma emitting radionuclides in Par Pond sediment were examined in situ with an underwater HPGe detector prior to and following a 19 ft drawdown of the pond in 1991 to address dam repairs. These measurements provide a ma...
The SRNL UCF is capable of detecting extremely small amounts of radioactivity in samples, providing applications in forensics, environmental analyses, and nonproliferation. Past customers of the UCF have included NASA, (Long Duration Exposure Facility) the IAEA, (Iraq), and nonproliferation concerns. The SRNL UCF was designed to conduct ultra-low level gamma-ray analyses for radioisotopes at trace ...
... were to Compton scatter in the primary detector and be captured in the shield, the coincidence of the two events would cause the event in the HPGe ...
DTIC Science & Technology
All low-level laboratories require HPGe detectors to meet certain technical specifications, some of which are not available from manufacturers prior to purchase. Ensuring an HPGe detector is fit for purpose requires the purchase and installation of a detector in the laboratory, incurring both ...
Non-linearities in the energy response of gas detectors in the regions of the absorption edges of the detection medium are well documented. Monte Carlo calculations show that the non-linearity results from differences in efficiencies for converting absorbed radiation into ionisation for different atomic sub-shells. Energy non-linearity in germanium-based ...
We have developed a pulser that is able to generate a simulated signal from a high-purity germanium (HPGe) detector for various plutonium isotopes. In this paper we describe the development of an ''isotopics'' pulser for the simulation of signals that are produced by an HPGe ...
An efficiency calibration method has been developed to measure radioactivity of volume samples with HPGe detectors. The method has two main procedures. One is a point-source calibration at a representative point near the detector. The position of the representative point is determined by Monte Carlo simulations. ...
A Lawrence Livermore National Laboratory-developed pulse shape analysis (PSA) technique which performs real-time Compton suppression in High Purity Germanium (HPGe) detectors without the use of anti-coincidence detectors is described. Some preliminary measurements of a variety of sources with a standard HPGe ...
The Gamma-Ray multi-group analysis code MGA developed at Lawrence Livermore National Laboratory has been widely used in the area of gamma-ray non-destructive plutonium assay. This plutonium isotopic analysis code de-convolutes the complicated, 100-keV x-ray and gamma-ray region to obtain the ratio of Pu isotopes. Calibration of the detector efficiency is ...
The representative point method for the efficiency calibration of volume samples has been previously proposed. For smoothly implementing the method, a calculation code named CREPT-MCNP has been developed. The code estimates the position of a representative point which is intrinsic to each shape of volume sample. The self-absorption correction factors are also given to make ...
Characteristics of a new ring Compton scatter camera are described. This camera is designed to image medium energy (0.5 to 3 MeV) gamma-ray fields. It consists of two position sensitive detector arrays: a 4X4 planar array of high purity germanium (HPGe) crystals and a ring array of up to 64 NaI(TI) crystals. Past evaluations of Compton cameras have ...
The partial-body counter currently installed at KIT is under redesign to add whole-body counting capabilities and replace the current phoswich detectors with HPGe ones, capable of detecting low energy photons ((210)Pb, (241)Am). Different configurations for the positioning of the subject have been tested with the aid of Monte Carlo simulations and the ...
Plutonium gamma-ray data analysis using MGA in the two-detector mode can provide information more refined than the gamma-ray analysis using MGA in the one-detector mode. Prior to the introduction of the new type of ORTEC coaxial detector, which has good resolution at 100-keV region and good efficiency at 1 MeV, the ...
A HPGe detector incorporated into a Compton suppression and pair spectrometer yields a continuum suppression factor of over 30. Cryostat housing requirements to obtain such suppression are discussed, sample spectra are presented, and several experiments m...
Planar HPGe detectors designed for detection of charged particles in low-temperature nuclear orientation experiments were tested in the temperature range between 2 and 77 K. Various detector characteristics were studied. The detectors gave good and stable results for registration of both charged particles and ...
The Smithsonian Astrophysical Observatory is performing the calibration of the AXAF High Resolution Mirror Assembly (HRMA) at the Marshall Space Flight Center. In order to determine the absolute incoming photon flux at the calibration facility a high purity germanium (HPGe) detector and an identical spare detector have been chosen as ...
A gamma spectrum of a Pu-C source is measured using a p-type HPGe detector, whose three peaks (full energy, single-escape and double-escape peak) can be used as a calibration source for the beam energy measurement system of BEPCII. The effect of fast neutron damage on the energy resolution of the HPGe detector is ...
We describe an improvement of the neutron activation system in operation on the Frascati Tokamak Upgrade (FTU) tokamak for the measurement of the total neutron yield. A HPGe well-type detector (200 cm{sup 3} active volume) is used to detect the photoemission from neutron activated samples ({sup 115m}In336.2 keV {gamma} rays from DD neutrons on indium for ...
In double-sided strip high-purity germanium (HPGe) detectors, improved position resolution can be obtained through axial and lateral strip interpolation by means of pulse shape analysis. Yet, only a small fraction of events can be interpolated in both the axial and lateral dimensions, meaning that the best possible imaging performance is delivered at the ...
A novel technique for measuring the HPGe detector pulse shape as a function of the ?-ray interaction position inside the detector volume is presented. This technique is based on a specific pulse shape comparison procedure. Its main feature is that it allows to characterize the 3D position response of a HPGe ...
A high-resolution gamma ray spectroscopy (HRGS) system has been installed at the Advanced Material Accountancy Glovebox Assay (AMAGB) System so that neutron and gamma ray measurements can occur simultaneously on material transfer containers. This equipment was installed in August 2000 at the Plutonium Fucl Production Facility (PFPF) in Japan. It is anticipated that placing the HRG6 system at the ...
The Safeguards Science and Technology Group at the Los Alamos National Laboratory has accumualted a large quantity of high-purity germanium (HPGe) detector gamma-ray spectra in support of the development of the FRAM (Fixed Energy, Response Function Analysis with Multiple Efficiencies) gamma-ray isotopic analysis software. These data, ...
The next generation of experiments in particle astrophysics will require extremely low and well-known backgrounds. This requires performing experiments with low activity materials and going underground to escape the ubiquitous cosmic-ray background. Current radiometric assays using low background HPGe detectors at the recently established Kimballton ...
Cylindrical concrete and stainless steel blocks were irradiated one week by the cyclotron of Institute for Nuclear Study of University of Tokyo. Their gamma-ray activities were measured by a high-purity Ge( HPGe ) detector and simultaneously the residual exposure rates were measured by the GM survey-meter. Radionuclides and their gamma-ray activities were ...
ABSTRACT Physics experiments, environmental surveillance, and treaty verification techniques continue to require increased sensitivity for detecting and quantifying radionuclides of interest. This can be done by detecting a greater fraction of gamma emissions from a sample (higher detection efficiency) and reducing instrument backgrounds. A current effort for increased ...
A high-efficiency Compton background suppressed gamma-ray spectrometer by anti-coincidence counting with a NaI(Tl)-shield around a central HPGe-detector for in-beam prompt gamma-ray neutron activation analysis (AC-PGNAA) using a Cf-252 neutron source has ...
A low-level gamma-ray spectrometry system, based on an HPGe-detector with 92% relative efficiency recently installed in the underground laboratory Felsenkeller at 110 m water equivalent (w.e.) depth, is described. The integral background count rate normalised to the Ge-crystal mass in the energy range from 40 keV until 2.7 MeV of 0.034 s(-1)kg(-1) has been ...
A fast-timing method to determine lifetimes of nuclear states in the sub-nanosecond domain is presented. It is based on in-beam measurements of triple-gamma coincidences in heavy-ion fusion-evaporation reactions, performed with an array of HPGe and LaBr3:Ce detectors. The high-energy resolution HPGe detectors are ...
The ASEDRA algorithm (Advanced Synthetically Enhanced Detector Resolution Algorithm) is a tool developed at the University of Florida to synthetically enhance the resolved photopeaks derived from a characteristically poor resolution spectra collected at room temperature from scintillator crystal-photomultiplier detector, such as a NaI(Tl) system. This work ...
An analytical expression for the so-called full-energy peak efficiency epsilon(E) for cylindrical source with perpendicular axis to an HPGe detector is derived, using point-source measurements. The formula covers different measuring distances, matrix compositions, densities and gamma-ray energies; the only assumption is that the ...
The DESPEC HPGe array is a part of the NuSTAR project at FAIR, Germany. It is aimed at the spectroscopy of the stopped decaying exotic nuclei. Segmented ?-ray tracking detectors are proposed for this array in order to maximize detection efficiency and background suppression when searching for very rare events. Two types of ...
Jun 16, 2011... with the MESSENGER XRS and GRS high-purity germanium (HpGe) detectors. ... Date Presented: June 16, 2011, at a NASA press conference ...
NASA Website
were detected by 8 HPGe detectors, arranged at backward (145) and forward (35) angles, as depicted is visible, surrounded by 8 HPGe detectors. Five of the germanium detectors were set at 145 and 3 at 37Vol. 42 (2011) ACTA PHYSICA POLONICA B No 3�4 LIFETIME MEASUREMENT IN THE N = Z NUCLEUS 44 ...
The development results of the high resolution N-type HPGe coaxial detectors are reported. The dependence of the reverse V-I(sub L) characteristic on the implantation dose of detector outside P(sup +)N junction was investigated under the condition of the ...
The (n,p) reaction cross sections of {sup 16}O in the neutron energy range from 13.6 to 14.9 MeV were measured by the activation method. The gamma-ray counting technique was applied, and the cross sections were determined relative to the {sup 27}Al(n,p){sup 27}Mg reaction cross sections. The neutrons were produced via the {sup 3}H(d,n){sup 4}He reaction on a SAMES T-400 neutron generator, and the ...
This paper presents new results obtained using the US national gamma-ray facility Gammasphere, which has been operating at the ATLAS accelerator at Argonne National Laboratory since January 1998. Gammasphere was built at Lawrence Berkeley Laboratory and used primarily as a powerful spectrometer for studying nuclei at the highest spins. For pioneering research in the high-spin regime, it was ...
The availability of burnup data is an important requirement in any systematic approach to the enhancement of safety, economics and performance of a nuclear research reactor. This work presents the theory and experimental techniques applied to determine, by means of nondestructive gamma-ray spectroscopy, the burnup of Material Testing Reactor (MTR) fuel elements irradiated in the IEA-R1 research ...
The Analytical Development Section of SRTC was requested by the Facilities Disposition Division (FDD) to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. The 321-M facility was used to fabricate enriched uranium fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the ...
An empirical equation describing the photopeak efficiency of Ge(Li) and high purity germanium (HPGe) photon detectors in the energy range from 60 keV to the onset of escape peak losses is presented. The functional parameters are fitted to calibration points obtained from long-lived commercially available standards (241Am, 109Cd, 57Co, ...
Two methods for measuring 222Rn exhalation and effective 226Ra in soil samples were studied. In the first determination, the method employed was based on the adsorption of radon onto activated charcoal and subsequent measurement of the activity of its daughters with an HPGe (high-purity germanium) detector. In the second, vials containing an aqueous ...
The space charge distribution inside highly segmented large volume HPGe detectors determined from capacitance�voltage (CV) measurements is investigated. A computer code was developed to understand the impact of impurity concentrations on the resulting capacitances between core contact and outer contact for HPGe ...
This paper reports on the performance and use of a low background HPGe detector, which was operated in the Holborn Underground laboratory from May 1990 to July 1993, and on some of the results obtained from it. The analysis includes sections on measuring the efficiency of the system and a discussion of the contributions to the ...
Gamma-ray spectroscopic systems with high efficiency and energy resolution have become important in many fields. Conventional systems with analog shaping are being replaced by digital systems that can provide higher throughput, better energy resolution and better stability. Therefore, we present the development of our new versatile real time Multi-Channel Analyzer with digital ...
The next generation of low background detectors will explore the frontiers of low energy neutrino physics, neutrinoless double beta decay, and direct dark matter searches. These experiments all require materials with minimal and tightly controlled radioactive contaminants. The KURF (Kimballton Underground Research Facility) is now home to a gamma counting facility, consisting ...
The 232Th(n,?)233Th thermal neutron-capture reaction cross section was measured using targets of ~ 1.5 mg of high-purity metallic thorium irradiated in the IPEN IEA-R1m 5 MW pool research reactor. The 197Au(n,?)198Au reaction was used to monitor the thermal and epithermal neutron fluxes in the irradiation position, which was found using the Westcott formalism. The residual gamma-ray activity was ...
The paper describes a detector model which is used by the Neutron Activation Analysis PRognosis and Optimization (NAAPRO) code for modeling ?-ray spectra of the activation products generated by neutron irradiation of hypothetical multielement samples with user-specified composition. Distinctive features of the model are its sufficiently high productivity, flexibility and ...
The project aimed at modelling an HPGe well detector in view to predict its photon-counting efficiency by means of the Monte Carlo simulation code GEANT4. Although a qualitative and quantitative description of the crystal and housing was available, uncertainties were associated to parameters controlling the ...
Gamma spectroscopists often must analyze samples with geometries for which their detectors are not calibrated. The effort to experimentally recalibrate a detector for a new geometry can be quite time consuming, causing delay in reporting useful results. Such concerns have motivated development of a method for extrapolating HPGe ...
In reference 1 the authors described {gamma}-ray holdup assay of a Mossbauer spectroscopy instrument where they utilized two axial symmetric cylindrical shell acquisitions and two disk source acquisitions to determine Am-241 and Np-237 contamination. The measured contents of the two species were determined using a general detector efficiency calibration ...
calculation relying only on changes in energy resolution. GammaTracker is competitive with the HPGe system data was artificially modified to match the energy resolution of the CdZnTe detectors used in Gamma, detector areas, and energy resolutions, the GammaTracker system outperforms the HPGe system at energies
fraction of events. TrueScatter Other #12;ProSPECTus: What is new? ProSPECTus is a Compton Imager � Radical � Scatter detector: high Compton scattering cross-section at 141keV: Si(Li) and HPGe � Absorber detector Intensity Compton Imaging with HPGe � 30mm & 50mm separation between scatterer & ...
high-purity germanium (HPGe) gamma detectors provide superior resolution, they need cryogenic cooling The MIP Monitor used an HPGe detector to perform gamma-ray spectroscopy on BWR fuel elements dissolved AJ Casella EA Jordan RN Christensen JW Hines AM Lines SM Peper TG Levitskaia CG Fraga January 2011
The amount of 137Cs was measured in the PAR pond on the Savannah River Site. An underwater HPGe detector was used to inventory the gamma-emitting radionuclides in the sediment of the pond. The description and process of the equipment was given in this report. From the analysis of the compiled data, the drawdown can proceed in radiological guide lines.
At the Savannah River Site during the past year, an underwater high-purity germanium (HPGe) detector was used to inventory [sup 137]Cs in sediment of a reactor cooling pond. Dam maintenance required lowering the water level of the pond by 6 m, and the gamma-emitting radionuclides in the exposed sediment needed preevaluation. Although earlier [sup 137]Cs ...
The 1001 keV gamma line of (234m)Pa became important in gamma spectrometric measurements of samples with (238)U content with the advent of development of HpGe detectors of great dimension and high efficiency. In this study the emission probability of the 1001 keV (Y(gamma)) peak of (234m)Pa, was determined by gamma-ray spectrometric ...
The Advanced GAmma Tracking Array (AGATA) is a European project that is aiming to construct a complete 4? High Purity Germanium (HPGe) gamma-ray spectrometer for nuclear structure studies at future Radioactive Ion Beam (RIB) Facilities. The proposed array will utilise digital electronics, Pulse Shape Analysis (PSA) and Gamma-Ray Tracking (GRT) algorithms, to overcome the ...
High purity germanium (HPGe) detectors used in radionuclide assay systems such as Radionuclide Aerosol Sampler/Analyzer (RASA) systems must operate unattended for long periods of time. Currently, the performance and reliability of commercially available l...
Ytterbium-169 is being considered as a new radiation source for brachytherapy applications. This radioisotope emits photons with energies ranging from 50 to 308 keV (average energy 93 keV) and decays with a half life of 32 days. For these reasons, it is believed to offer radiological and radiobiological advantages over some other isotopes currently in use. One impediment to widespread clinical use ...
The GRABGAM code has been developed for analysis of ultra-low-level HPGe gamma spectra. The code employs three different size filters for the peak search, where the largest filter provides best sensitivity for identifying low-level peaks and the smallest filter has the best resolution for distinguishing peaks within a multiplet. GRABGAM basically generates an integral ...
In paper based on a model of coaxial detetor with one-open face (spherical coaxial detector - SC - detector) E(r)-dependenceis shown experimentally to be stronger than in coaxial detectors with two open faces (right coaxial detector - RC - detector). The ...
A prompt gamma-ray neutron activation analysis (PGNAA) system was evaluated for the quantification of chlorinated compounds in soil. The system evaluation was divided into two phases. In phase one, the response of an n-type HPGe detector (20 percent relative efficiency) to point sources of 60Co and 152Eu was determined experimentally ...
The goal of this demonstration was to show that it is possible to generate electronic signals that can accurately mimic the signals that are produced by a high-purity germanium (HPGe) gamma-ray detector. As an example of this fidelity, we decided to show that it was possible to perform a complex, multiplet-resolution analysis of a portion of the spectrum ...
The authors examined the accuracy and sensitivity levels for three variations on the TGS method: the original TGS method using a high-purity germanium (HPGe) detector to measure net areas of full-energy gamma-ray peaks; a modified HPGe-detector method that uses net areas for the transmission analysis and the gross count TGS (GC-TGS) ...
Many measurements for environmental levels of the radioactive content require that the gamma-ray detector be low background, that is, free of any radioactive content. This is, of course, not possible, but the radioactivity in the detector must be reduced to as low a value as possible. The description or specification of the background spectrum necessary to ...
A two-dimensional analysis of three coincident gamma-rays in (108)Ag(m) decay, detected by two NaI(Tl) scintillation detectors, allows a direct measurement of the source activity. A modification of the Eldridge-Crowther formulas derived originally for (125)I was done recently for the case of two coincident gamma-rays in (60)Co decay (Volkovitsky and Naudus, 2009). A similar ...
The current chest wall thickness prediction equation is not applicable to use in routine lung counting measurements for detection of low energy photons (17-60 keV) within the lungs of male and female subjects. The current chest wall thickness prediction equation was derived for the NaI-CsI {open_quotes}phoswich{close_quotes} detection system, which is not the routine detection system in use; the ...
The current chest wall thickness prediction equation is not applicable to use in routine lung counting measurements for detection of low energy photons (17--60 keV) within the lungs of male and female subjects. The current chest wall thickness prediction equation was derived for the NaI-CsI "phoswich" detection system, which is not the routine detection system in use; the subject position was ...
A low-background ?-ray spectrometer for environmental surveillance, emergency response, and environmental health research has been constructed. It consists of a 132% efficient HPGe detector, graded lead shielding, and muon-rejection shielding, as well as external steel and building shielding. Detailed operation of the ? spectrometer ...
Precise relative gamma-ray intensities of 56Mn and 72Ga produced by neutron irradiation of natural Mn3O4 and enriched 71Ga2O3 (99.8%) were measured by an HPGe detector with highly-precisely calibrated detection efficiencies. As both nuclides exhibit no beta branch to the ground state, the absolute emission probabilities of the 846.8 ...
The ? decay of 11 Li has been investigated at TRIUMF-ISAC using a high-efficiency array of Compton suppressed HPGe detectors. From a line-shape analysis of the Doppler-broadened peaks observed in the 10 Be ? spectrum, both the half-lives of states in 10 Be and the energies of the ? -delayed neutrons feeding those states ...
The Czech Metrology Institute performs calibration and verification of noble gases stack monitors in nuclear power plants and nuclear research facilities. Together with Kr-85 and Xe-133, the radionuclide Ar-41 is measured using HPGe detectors and its activity is determined using a gamma-ray peak at 1293keV. The counting efficiency used ...
A total of 31 samples from Long Duration Exposure Facility (LDEF), including materials of Al, V, and steel trunnions were analyzed by ultralow level gamma spectrometry. The study quantified particle induced activations of Na-22, Sc-46, Cr-51, Mn-54, Co-56, Co-57, Co-58, and Co-60. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing ...
A study of the coincidence summing of X- and gamma-rays of 133Ba has been presented. The detailed computation of the 133Ba spectra was performed by application of the previously published theory by Novkovic et al. The theory is based on tracking all decay paths and their outcomes, i.e., deposited energies in the detector and probabilities for those events. The method enables ...
A deterministic code was developed for the calculation of true coincidence summing correction factors and has been incorporated into the EFFTRAN tool. The approach is aimed at the analysis of extended samples measured on p-type HPGe detectors in environmental gamma-ray spectrometry and was verified against the results of a state-of-the-art full Monte Carlo ...
A solution of 169Yb was absolutely standardized by the 4pi(EC,X)-gamma coincidence counting method and the result was used to obtain direct measurements of gamma-ray emission probabilities with a coaxial HPGe detector. The empirical relation proposed by (Va�o, F., Gonzalez, L., Gaeta R., Gonzalez, J.A., 1975. An empirical function which relates the slope ...
Detection efficiency of a gamma-ray spectrometry system is dependent upon among others, energy, sample and detector geometry, volume and density of the samples. In the present study the efficiency calibration curves of newly acquired (August 2008) HPGe gamma-ray spectrometry system was carried out for four sample ...
Understanding the radiation background at the north crossing point (NCP) in the tunnel of BEPCII is crucial for the performance safety of the High Purity Germanium (HPGe) detector, and in turn of great significance for long-term stable running of the energy measurement system. Therefore, as the first step, a NaI(Tl) detector is ...
A simulation programme based on the Geant4 toolkit has been developed to simulate the coincident responses of a plastic scintillator and an HPGe detector to the cosmic-ray muons. The detectors are situated in a low-level underground laboratory (25 m.w.e). Primary positions, momentum directions and energies of the muons are sampled from ...
An HPGe gamma probe designed to monitor radioactive nuclides in environmental water in situ is described. The probe is equipped with a 15% HPGe detector and an associated spectrum analyzer. Laboratory tests were performed to evaluate its operating depth, detecting sensitivity, detecting volume and the detection limits of radionuclides. ...
We present current results on the theoretical and experimental studies of optimal cryogenic cooling of gamma-ray spectrometers based on high-purity germanium (HPGe) detectors. We show that the technology of cryogenic heat pipe diodes (HPDs) usually allows one to meet cooling requirements with minimal weight, power consumption and cost. Results of computer ...
The Multi-sensor Airborne Radiation Survey Flight Engineering project (MARS FE) has designed a high purity germanium (HPGe) crystal array for conducting a wide range of field measurements. In addition to the HPGe detector system, a platform-specific shock and vibration isolation system and environmental housing have been designed to ...
Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe to Majorana and other double-beta decay experiments could come from decays of alpha-emitting isotopes-neutrino double-beta decay. 0: Short-hand for double-beta decay with a majoran () emission. DAQ: Data
The neutron activation analysis group within the Analytical Sciences Laboratory analyzes 3000-5000 samples annually for a wide variety of analytes. Due to the high sample load, it is imperative that the gamma spectroscopy counting system be automated to maximize the efficiency of the system while ensuring the accuracy of the analyses. Using a Zymark robotic system, Compumotor ...
We have evaluated a collimator-less gamma-ray imaging system, which is based on thin layers of double-sided strip HPGe detectors. The positions of individual gamma-ray interactions will be deduced by the strip addresses and the Ge layers which fired. Therefore, high bandwidth pulse processing is not required as in thick Ge detectors. ...
We have evaluated a collimator-less gamma-ray imaging system, which is based on thin layers of double-sided strip HPGe detectors. The position of individual gamma-ray interactions will be deduced by the strip addresses and the Ge layers which fired. Therefore, high bandwidth pulse processing is not required as in thick Ge detectors. ...
This work addresses the energy spectrum correction due to increased charge carrier collection times in larger HPGe spectrometers. The energy of the radiation interaction is expected to be proportional to the total collected charge. This is increasingly not true with larger HPGe spectrometers. Some charge is lost as the total charge travels from the ...
The new International Electrotechnical Commission (IEC) standard for describing the background makes the specification of the background in a high-purity germanium (HPGe) detector simple, unambiguous, and related to how the detector will be used. Users and manufacturers will finally be speaking the same language on this subject. ...
A total absorption detector, which is composed of a through-hole type HPGe detector coupled with a surrounding annular anti-Compton BGO detector, has been developed for ??-decay energy (Q?) measurements of nuclei far off from the ?-stability line. This detector can measure radiations with an ...
High-purity germanium (HPGe) detectors will be used in future space missions for gamma-ray measurements and will be subject to interactions with energetic particles. To simulate this process several large-volume n-type HPGe detectors were incrementally exposed to a particle fluence of up to 10{sub 8} protons cm{sup ...
The low-noise and pulse-shape discrimination characteristics of point-contact High-Purity Germanium (HPGe) detectors have made them a promising detector technology for neutrinoless double-beta (0???) decay experiments and direct dark matter searches. In 0??? searches, substantial background rejection can be achieved if one can identify ...
Voxel phantoms and Monte Carlo methods are of considerable interest in calibrating in vivo counting applications for radioactive body burden such as whole-body counters. At the Japan Atomic Energy Research Institute (JAERI), a calculation code--UCWBC code--for whole-body counter calibrations using voxel phantoms has been developed as an EGS4 Monte Carlo user code. To validate the UCWBC code for ...
In June-August 2006 an expedition with the aim to look for low-radioactive archaeological lead at the bottom of the Black Sea, near the Crimean peninsula (Ukraine) was organised by a Korean-Ukrainian collaboration. The first samples with {approx}0.2 tons of total mass were found at a depth of 28 m among the relics of an ancient Greek ship. Their age has been dated to the first century B.C. This ...
Many tasks in different sectors of dosimetry are very complex and highly sensitive to changes in the radiation field. Often, only the simulation of radiation transport is capable of describing the radiation field completely. Down to sub-cellular dimensions the energy deposition by cascades of secondary electrons is the main pathway for damage induction in matter. A large number of interactions ...
A prototype electronics package of amplifier, ADC, pulser, data-bus interface, bias supply and low voltage supply has been developed to process high resolution data from rugged intrinsic germanium detectors with high reliability in a harsh environment. This sturdy modular package attachable to the dewar of a rugged detector oriented horizontally or ...
We discuss the possible use of a progressive detection technique based on pixel detectors for the study of double beta decay (??) processes. A series of background measurements in various environments (surface laboratory, underground laboratory, with and without Pb shielding) was performed using the TimePix silicon hybrid pixel device. The pixel detector ...
This paper compares the performance of the Active Well Coincidence Counter (AWCC) with the performance of high resolution gamma spectrometry using an HPGe detector to nondestructively assay highly enriched (HEU) oxide. Traditionally the AWCC was considered to be the more appropriate instrument for this measurement. Although the AWCC had a high degree of ...
A mobile NDA system was composed and qualified for Safeguards measurements of multiple standard waste boxes (SWB) generated as a result of clean-out activities at Hanford�s Plutonium Finishing Plant (PFP). The system included a neutron slab counter and high purity germanium (HPGe) detector. PC/FRAM software was used to determine the isotopic composition ...
A highly segmented coaxial HPGe detector was operated in a low background counting facility for over 1 year to experimentally evaluate possible segmentation strategies for the proposed Majorana neutrino-less double-beta decay experiment. Segmentation schemes were evaluated on their ability to reject multi-segment events while retaining single-segment ...
The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in 76Ge. Initially, Majorana aims to construct a prototype module to demonstrate the potential of a future 1-tonne experiment. The design and potential reach of this prototype Demonstrator module are presented.
We made a search for hadronic axions, which could be emitted from the Sun in the axiobremsstrahlung process and absorbed in the HPGe detector by axioelectric effect. An upper limit on hadronic axion mass of 100 eV is obtained at the 95% confidence level.
A detailed description of the method is presented. The range of application is shown. The calibration of the in-situ gamma ray spectrometer with a HPGe semiconductor detector and the evaluation of the spectra are described. A measuring time of about 15-30...
The goal of this demonstration was to show that it is possible to generate electronic signals that can accurately mimic the signals that are produced by a high-purity germanium (HPGe) gamma-ray detector. As an example of this fidelity, we decided to show ...
resolution g-spectroscopy at 478 keV and 46.5 keV respectively with HPGe detectors at the Laboratory of Environmental Radiochemistry of the Bologna University. ... Responsible NASA Official: Lola Olsen. Last Updated: August 2011 .
We present position sensitivity measurements obtained with one of the 32-fold segmented HPGe detectors from Michigan State University. These measurements were performed with a collimated beam of {sup 137}Cs gamma rays scattered by 90 degrees. This deposits 374 keV at a given location inside the crystal. A position resolution can be determined over many ...
The Ortec trans-SPEC is a portable gamma ray spectrometer which is approximately 10.4 kg in total weight and 37 cm � 16 cm � 32 cm in overall size It utilizes a P-type 50 mm diameter and 30 mm height coaxial HPGe detector and has more than 3 hours of battery life when fully charged. This paper details the experimental agreement found for one of these ...
The space charge distribution of a large volume highly segmented HPGe detector was determined by a non-destructive capacitance�voltage measurement. The capacitances between the 36 segments and the core were measured simultaneously with a precision pulser which was implemented in the core preamplifier. The pulser measurement was compared to and validated ...
In the new sub-micron beamline at the Lund Nuclear Microprobe facility a special large area HPGe X-ray detector has been installed. It consists of eight 100-mm2-size detector elements arranged in an annular formation around the beam entrance hole. Different parameters like FWHM, FWTM, peak-to-background ratio and peak-to-valley ratio ...
High-resolution, gamma- and x-ray spectrometry are used routinely in nuclear safeguards verification measurements of plutonium and uranium in the field. These measurements are now performed with high-purity germanium (HPGe) detectors that require cooling liquid-nitrogen temperatures, thus limiting their utility in field and unattended safeguards ...
Three synthetic multielement standards (SMELS I, II and III) and two reference materials (RMs), SL-3 and Soil-7 of IAEA were analyzed for validation of the k0-based internal monostandard neutron activation analysis (IM-NAA) method utilizing in-situ relative detection efficiency. The internal monostandards used in SMELS and RMs were Au and Sc, respectively. The samples were ...
In October 1996, the Department of Energy (DOE) and MINATOM agreed to use portable non-destructive assay (NDA) equipment to measure the {sup 235}U enrichment of material subject to the HEU Transparency agreement. A system based on the ''enrichment meter'' method and high-purity germanium (HPGe) detectors had been ...
In this work the Pulse Shape Analysis has been used to improve the time resolution of High Purity Germanium (HPGe) detectors. A set of time aligned signals was acquired in a coincidence measurement using a coaxial HPGe and a cerium-doped lanthanum chloride (LaCl3:Ce) scintillation detector. The analysis using a ...
Suppression systems reduce Compton backscattering counts in a gamma ray spectrum. Every system has particular calibration nuances due to differences in electronics, detectors and environment. This study examines several Compton suppression systems at the NIST Center for Neutron Research in an effort to produce a general guide to their setup and use rather than determine ...
The radon activity concentration in ground water from drilled and dug wells on the horst S�der�sen in Southern Sweden has been determined with two different methods, gamma activity measurements with a germanium HPGe detector and alpha activity measurements with plastic track detectors. The results are consistent. High activity ...
We have determined the ?-ray branching ratios in the ?^+ decay of ^32Cl using a high-purity Germanium (HPGe) detector at the Texas A&M University Cyclotron. Our experiment was motivated by a recent measurement of isospin symmetry breaking correction (?c) in ^32Ar which has implications for the extraction of Vud from other superallowed decays. The ...
A determination of the ? - ? angular correlation from ^22Na beta decay with the GAMMASPHERE array has been used to extract induced-tensor-currents contributions to the weak interaction. The result, together with other available experimental data yielded an unexpectedly large induced tensor (second class) component to the hadronic current, which is at variance with the Standard Model. A weak link ...
The radioactive beam facility at the University of Notre Dame nuclear structure laboratory has been used to produce a beam of ^6He at an energy of 28 MeV and with an intensity of 5� 10^5 pps. This radioactive beam was produced by 1-p transfer from a 30 MeV ^7Li primary beam on a ^4He gas cooled ^9Be target. The secondary beam was separated from non-reacting primary beam using the `Twinsol' dual ...
PGNAA is a very widely applicable technique for determining the presence and amount of many elements simultaneously in samples ranging in size from micrograms to many grams. PGNAA is characterized by its capability for nondestructive multi-elemental analysis and its ability to analyse elements that cannot be determined by INAA. By means of this PGNAA method we are able to increase the performance ...
PGNAA is a very widely applicable technique for determining the presence and amount of many elements simultaneously in samples ranging in size from micrograms to many grams. PGNAA is characterized by its capability for nondestructive multi-elemental analysis and its ability to analyse elements that cannot be determined by INAA. By means of this PGNAA method we are able to increase the performace ...
Position sensitive, high-purity germanium (HPGe) planar orthogonal strip detectors are currently being used for an increasing number of gamma imaging applications where high efficiency is required. Larger volume crystals are being employed to improve detection efficiency, and therefore, electrode signals show ...
Relative intensities of X- and gamma rays emitted in the decays of 131I, 166Ho, 198Au and 199Au have been measured precisely using a set of five detectors: 96.0 cm3 and 57.1 cm3 coaxial HPGe detectors, a 28.27 mm2 � 5.0 mm vertical planar HPGe detector and two 28.27 mm2 � 5.5 mm Si(Li) ...
Coincident ? rays from a 252Cf source were measured using an array of six segmented high-purity germanium (HPGe) Clover detectors each enclosed by 16 bismuth-germanate (BGO) detectors. The detectors were arranged in a cubic pattern around a 1?Ci252Cf source to cover a large solid angle for ?-ray measurement with a ...
The AMS fixed-wing and rotary-wing systems are critical National Nuclear Security Administration (NNSA) Emergency Response assets. This project is principally focused on the characterization of the sensors utilized with these systems via radiation transport calculations. The Monte Carlo N-Particle code (MCNP) which has been developed at Los Alamos National Laboratory was used to model the ...
The ability to detect contaminants at very low-levels in environmental samples promises early identification and correction of harmful industrial practices. To achieve this capability, the Savannah River Laboratory Underground Counting Facility (SRLUCF) was developed. This paper appraises resulting improvements in detection sensitivity, and discusses recent applications. SRLUCF utilizes hardware ...
During the last two years, a triple-to-double coincidence ratio (TDCR) system was assembled and adjusted at the CNEA-LMR, Argentina. The new counting system will add complementary capabilities to the absolute measurements section of the CNEA-LMR. This work describes its implementation and validation. Several checks and a set of beta-emitting standard solutions were used in order to perform the ...
A study on absorption of radon by different edible oils of plant origins produced and used in India was conducted in order to identify efficient radon-absorbing oils. A comparative study of radon absorption by edible oils of India with that of olive oil, which is known as a good absorber of radon, was also carried out. The study was performed by bubbling known concentrations ...
In this paper, the authors present results of a simulation of gamma-ray interactions in a high purity germanium detector (HPGe). Gamma-ray interactions have been divided into Compton events which leave only part of their energy in the detector and full energy events which leave all their energy in the detector. The ...
The interpretation of prompt gamma-ray spectra and the prediction of the detection limits and run times for samples require the knowledge of the detector response function. The detector system used at the Budapest Prompt-Gamma Activation Analysis facility consists of an HPGe detector and a Bismuth Germanate Compton ...
A new technique for the pulse-shape characterization of ?-ray position sensitive germanium detectors is presented. This method combines the pulse shape comparison scan (PSCS) principle with a ?-ray imaging technique. The latter is provided by a supplementary, high performance, position sensitive ?-ray scintillator detector. We describe the basic aspects of ...
This study at Savannah River was done to assist decisions on the future of L Lake, an artificial reservoir made in 1983-5 for additional cooling for L Reactor discharges. EG&G overflight NaI mappings prior to filling indicated that most of the man-made radionuclides were {sup 60}Co and (predominantly) {sup 137}Cs in the earlier stream beds lying beneath the lake. An underwater ...
The reaction ^16O(n, ?)^17O acts a neutron poison in the weak s-process by reducing the number of available neutrons in the stellar burning environment. The captured neutrons can be re-emitted into the stellar environment via the reaction ^17O(n, n)^20Ne, weakening the poisoning effect of ^16O. This channel competes with the reaction ^17O(,)^21Ne, so that in order to determine the strength of ^16O ...
The SmartPET project is the development of a prototype small-animal imaging system based on the use of Hyperpure Germanium (HPGe) detectors. The use of digital electronics and application of Pulse Shape Analysis (PSA) techniques provide fine spatial resolution, while the excellent intrinsic energy resolution of HPGe ...
The triple- and quadruple-escape peaks of 6.128 MeV photons from the F(p,??)19O16 nuclear reaction were observed in an HPGe detector. The experimental peak areas, measured in spectra projected with a restriction function that allows quantitative comparison of data from different multiplicities, are in reasonably good agreement with those predicted by Monte ...
In this work, a novel imaging technique for the spatial calibration of a gamma camera is presented. The latter is aimed for the characterisation of the charge signals of 3D-position sensitive HPGe detectors. The characterisation method itself is based on pulse shape comparison (PSC) technique. The performance of the device is improved by implementing a ...
The design of instrumentation for remote sensing presents special requirements in the areas of power consumption, long-term stability, and compactness. At the same time, the high sensitivity and resolution of the devices needs to be preserved. This paper will describe several instruments suitable for remote sensing developed under the sponsorship of the Defense Threat Reduction Agency (DTRA). The ...
The ORNL Whole Body Counter is one of the few in the country that is capable of assessment of body burdens of low-energy photon and x-ray emitters. This requires detectors and electronics specific for the task. Isotope identification and quantification capabilities are crucial at the facilities which deal with quantities of many radionuclides. The standard procedure for whole ...
To study the time properties of wide-aperture detectors of high-purity germanium (HPGe), the authors built a coincidence spectrometer; one channel used a scintillation detector while the other used a semiconductor detector. An XP-2020 photomultiplier with an NE-104 scintillator waa used to register Co 60 beta ...
This article presents experimental results obtained by the investigation of the efficiency of radioactive decontamination of a metal surface with alkyd and epoxy-urethane coating systems, which are used for the painting of military equipment. During the evaluation of the efficiency of decontamination, the impact of contaminants on the coating was not ...
The Safeguards Technology Program at the Lawrence Livermore National Laboratory is developing systems based on a compact electro-mechanically cooled high-purity germanium (HPGe) detector. This detector system broadens the practicality of performing high- ...
Radium was radiochemically separated from natural thorium. Thin {sup 228}Ra{yields}{beta}{sup -228}Ac sources were prepared and exposed to mica fission track detectors, and measured by an HPGe {gamma}-ray detector. The {beta}-delayed fission events of {sup 228}Ac were observed and its {beta}-delayed fission probability was found to be ...
Obtaining high-resolution gamma-ray measurements using high-purity germanium (HPGe) detectors in the field has been of limited practicality due to the need to use and maintain a supply of liquid nitrogen (LN(sub 2)). This same constraint limits high-resol...
The report described a system built around the Computing Gamma Spectrometer (PSA) LEA 74-008. The software primarily supports high-resolution gamma-ray spectroscopy using either a high-purity intrinsic germanium detector (HPGe) or a lithium-drifted germanium detector (Ge(Li)).
The accumulation of scales in production pipes is a common problem in the oil industry, reducing fluid flow and also leading to costly remedies and disposal issues. Typical materials found in such scale are sulphates and carbonates of calcium and barium, or iron sulphide. Radium arising from the uranium/thorium present in oil-bearing rock formations may replace the barium or calcium in these salts ...
This work presents the measures of the nuclear reaction rates along the radial direction of the fuel pellet by irradiation and posterior gamma spectrometry of a thin slice of fuel pellet of UO2 at 4.3% enrichment. From its irradiation, the rate of radioactive capture and fission had been measured as a function of the radius of the pellet disk using a Ortec GMX HPGe ...
Coded-aperture gamma-ray imaging is a mature technology that is capable of providing accurate and quantitative images of nuclear materials. Although it is potentially of high value to the safeguards and arms-control communities, it has yet to be fully embraced by those communities. One reason for this is the limited choice, high-cost, and low efficiency of commercial ...
In this paper we discuss the Smart Positron Emission Tomography (PET) imaging system being developed by the University of Liverpool in conjunction with CCLRC Daresbury Laboratory. We describe the motivation for the development of a semiconductor-based PET system and the advantages it will offer over current tomographs. Details of the detectors and associated electronics are ...
In the context of the n{sub T}OF Collaboration, the measurement of the cross section of the reaction {sup 241}Am(n,2n){sup 240}Am, has been performed, for the first time at neutron energies from 8.8 to 11.4 MeV, by the activation method, relative to the {sup 27}Al(n,a){sup 24}Na reaction reference cross section. The monoenergetic neutron beam was produced at the 5.5 MV TANDEM accelerator of NCSR ...
Studies on radon monitoring are essential for countries actively involved in mining activities. Since large-scale mining activities have the potential to enhance the background radiation levels, a detailed study on indoor and outdoor radon levels, its diurnal variation with temperature, pressure and humidity for Botswana is initiated. The study is important because such studies for Botswana are ...
The ability to conduct automated trace radionuclide analysis at or near the sample collection point would provide a valuable tool for emergency response, nuclear forensics and environmental monitoring. Pacific Northwest National Laboratory is developing systems for this purpose based on dual gamma-ray spectrometers, e.g. NaI(TI) or HPGe, combined with thin organic scintillator ...
gamma-Spectrometry is a basic and widely applied method in nuclear security and nuclear safeguards areas. For addressing the growing needs in education and training, in research and development as well as in practical gamma-spectrometry in these areas, Monte Carlo based web-accessible gamma-spectrum modelling tools have been developed for the European Commission's Nucleonica portal at ...
The procedure followed by the Laborat�rio de Metrologia Nuclear at the IPEN-CNEN/SP, in S�o Paulo, for the standardization of 152Eu is described. The disintegration rate of 152Eu has been measured using the 4pi beta-gamma coincidence technique, using a 4pi proportional counter, filled with P-10 gas and operated at 0.1 MPa, coupled to one HPGe detector ...
