Download or read book High dose Neutron Detector Development written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of advanced sustainable nuclear fuel cycles relying on used nuclear fuel is one of the key programs pursued by the DOE Office of Nuclear Energy to minimize waste generation, limit proliferation risk and maximize energy production using nuclear energy. Safeguarding of advanced nuclear fuel cycles is essential to ensure the safety and security of the nuclear material. Current non-destructive assay (NDA) systems typically employ fission chambers or 3He-based tubes for the measurement of used fuel. Fission chambers are capable of withstanding the high gamma-ray backgrounds; however, they provide very low detection efficiency on the order of 0.01%. To benefit from the additional information provided by correlated neutron counting [1] higher detection efficiencies are required. 3He-based designs allow for higher detection efficiencies; however, at the expense of slow signal rise time characteristics and higher sensitivity to the gamma-ray backgrounds. It is therefore desirable to evaluate and develop technologies with potential to exceed performance parameters of standard fission chamber-based or 3He-based detection systems currently used in the NDA instrumentation.
Download or read book Neutron Generators for Analytical Purposes written by International Atomic Energy Agency and published by IAEA Radiation Technology Repo. This book was released on 2012 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication addresses recent developments in neutron generator (NG) technology. It presents information on compact instruments with high neutron yield to be used for neutron activation analysis (NAA) and prompt gamma neutron activation analysis in combination with high count rate spectrometers. Traditional NGs have been shown to be effective for applications including borehole logging, homeland security, nuclear medicine and the on-line analysis of aluminium, coal and cement. Pulsed fast thermal neutron analysis, as well as tagged and timed neutron analysis, are additional techniques which can be applied using NG. Furthermore, NG can effectively be used for elemental analysis and is also effective for analysis of hidden materials by neutron radiography. Useful guidelines for developing NG based research laboratories are also provided in this publication.
Download or read book Development of a Solid State Neutron Detector for SNAP 10A written by A. Chesavage and published by . This book was released on 1966 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Development of the Planar Miniaturized Fast Neutron Detector written by Luke Stegeman and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel fast neutron spectrometer concept called the Miniaturized Fast Neutron Detector has been computationally developed and characterized via a series of radiation transport simulations. The planar version of the Miniaturized Fast Neutron Detector consists of a plastic converter layer situated in front of an arbitrary number of stacked, electrically isolated thin-silicon diode detectors. Ideally, incoming neutrons impinge upon the plastic, produce recoil ions, and those recoil ions deposit energy in one or more of the diode detectors placed behind the plastic. The spectrometer is capable of reconstructing incident neutron energy spectra without a priori information via at least two distinct unfolding algorithms. The ultimate purpose of the device is to act as an advanced personal dosimeter or area monitor with high position resolution to improve the accuracy of local radiation risk estimates due to secondary neutron radiation. In this work, the device's ability to unfold three distinct incident neutron energy spectra, the spectroscopic effectiveness of the device as a function of incident integral neutron fluence, and a set of strategies for optimizing and mathematically generalizing the device geometry are all presented. Radiation transport simulations were conducted to generate absorbed dose response functions for each diode detector and to compute the absorbed dose in each diode detector due to incident 252Cf, AmB, and AmBe neutron energy spectra as a function of integral neutron fluence. These data are used to test the unfolding capability of the device and characterize its spectroscopic effectiveness. Two unfolding algorithms are considered: the matrix inversion unfolding method, which employs a non-negative least-squares algorithm, and the SPUNIT method. Further radiation transport simulations and analyses were conducted to develop a strategy to optimize the dimensions of the plastic conversion layer and the diode detectors for any arbitrary neutron energy range so that individual device iterations can be tailored to various environments. The results of this work demonstrate that the planar Miniaturized Fast Neutron Detector is capable of unfolding a diverse range of incident neutron energy spectra without a priori information. The effectiveness of the device is quantified as a function of integral neutron fluence and this quantity can be used to determine the minimum integral neutron fluence necessary to generate acceptable unfolded neutron energy spectra (and, by extension, dosimetric quantities and risk-related metrics). The results also demonstrate that the efficiency and energy discrimination capabilities of the current iteration of the device (one with 20 stacked diode detectors) can be improved by decreasing the thickness of the plastic conversion block and increasing the number of uniformly sized diode detectors (or gradually increasing the thickness of diode detectors as a function of device depth).
Download or read book Neutron Dosimetry written by John W. Baum and published by . This book was released on 1955 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Attenuation of Gamma Rays and Neutrons in Reactor Shields written by Herbert Goldstein and published by . This book was released on 1957 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High dose Neutron Detector Project Update written by and published by . This book was released on 2016 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: These are the slides for a progress review meeting by the sponsor. This is an update on the high-dose neutron detector project. In summary, improvements in both boron coating and signal amplification have been achieved; improved boron coating materials and procedures have increase efficiency by ~ 30-40% without the corresponding increase in the detector plate area; low dead-time via thin cell design (~ 4 mm gas gaps) and fast amplifiers; prototype PDT 8" pod has been received and testing is in progress; significant improvements in efficiency and stability have been verified; use commercial PDT 10B design and fabrication to obtain a faster path from the research to practical high-dose neutron detector.
Download or read book Neutron Detectors for High temperature Applications written by Edith B. Fehr and published by . This book was released on 1958 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a High count rate Neutron Detector with Position Sensitivity and High Efficiency written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: While the neutron scattering community is bombarded with hints of new technologies that may deliver detectors with high-count-rate capability, high efficiency, gamma-ray insensitivity, and high resolution across large areas, only the time-tested, gas-filled [sup 3]He and scintillation detectors are in widespread use. Future spallation sources with higher fluxes simply must exploit some of the advanced detector schemes that are as yet unproved as production systems. Technologies indicating promise as neutron detectors include pixel arrays of amorphous silicon, silicon microstrips, microstrips with gas, and new scintillation materials. This project sought to study the competing neutron detector technologies and determine which or what combination will lead to a production detector system well suited for use at a high-intensity neutron scattering source.
Download or read book The Development of 3He Neutron Detectors for Applications in High Level Gamma ray Backgrounds written by Howard O. Menlove and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a High Energy Neutron Detector written by and published by . This book was released on 1972 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detector is being developed for the measurement of high energy neutron fluences. A series of neutron energy thresholds are employed to yield spectral information. The method employed is to measure the fluences of elastically scattered recoil nuclei from low Z (4
Download or read book High Precision Thermal Neutron Detectors written by and published by . This book was released on 1994 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional position sensitive detectors are indispensable in neutron diffraction experiments for determination of molecular and crystal structures in biology, solid-state physics and polymer chemistry. Some performance characteristics of these detectors are elementary and obvious, such as the position resolution, number of resolution elements, neutron detection efficiency, counting rate and sensitivity to gamma-ray background. High performance detectors are distinguished by more subtle characteristics such as the stability of the response (efficiency) versus position, stability of the recorded neutron positions, dynamic range, blooming or halo effects. While relatively few of them are needed around the world, these high performance devices are sophisticated and fairly complex; their development requires very specialized efforts. In this context, we describe here a program of detector development, based on 3He filled proportional chambers, which has been underway for some years at Brookhaven. Fundamental approaches and practical considerations are outlined that have resulted in a series of high performance detectors with the best known position resolution, position stability, uniformity of reliability over time of this type.
Download or read book Handbook of Particle Detection and Imaging written by Claus Grupen and published by Springer Science & Business Media. This book was released on 2012-01-08 with total page 1251 pages. Available in PDF, EPUB and Kindle. Book excerpt: The handbook centers on detection techniques in the field of particle physics, medical imaging and related subjects. It is structured into three parts. The first one is dealing with basic ideas of particle detectors, followed by applications of these devices in high energy physics and other fields. In the last part the large field of medical imaging using similar detection techniques is described. The different chapters of the book are written by world experts in their field. Clear instructions on the detection techniques and principles in terms of relevant operation parameters for scientists and graduate students are given.Detailed tables and diagrams will make this a very useful handbook for the application of these techniques in many different fields like physics, medicine, biology and other areas of natural science.
Download or read book Neutron Detectors for Scattering Applications written by Yacouba Diawara and published by Springer Nature. This book was released on 2023-08-04 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the most common neutron detectors used in neutron scattering facilities and all of those in use at Oak Ridge National Lab. It starts describing the facilities, instruments and the critical detector parameters needed by various instruments. Then the key components of the 3He-based linear position-sensitive detectors as well as on their electronics, which require particular attention to signal processing and noise reduction, are introduced. One chapter is dedicated to the 3He alternatives where scintillators play a critical role. It also covers emerging neutron detection technologies including semiconductors, vacuum-based devices and their associated readouts, which will be required in the future for high rate and high-resolution neutron detectors. The authors explain the logic behind the choice of materials as well as the various constraints that neutron detectors must respect to be useful. Some of these constraints, such as efficiency and gamma-ray sensitivity are common to all neutron counters while others, like timing resolution, dynamic range, and peak counting rate, depend on the applications. The book guides experts, the nuclear science community, and young scholars through the physical processes and the required electronics in a way that is accessible for those not professionally involved in designing detector’s components and electronic circuits.
Download or read book Compendium of Neutron Spectra and Detector Responses for Radiation Protection Purposes written by International Atomic Energy Agency and published by . This book was released on 2001 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication is an update of Technical Report Series No. 318, Compendium of Neutron Spectra and Detector Responses for Radiation Protection Purposes (1990), that takes into account the major changes in the recommended energy dependence of risk related quantities, the increased importance of high neutron energies, the increased use of boron neutron capture therapy, promising new developments in detector design, new measured workplace spectra and improved calibration facilities. It includes the fluence to dose equivalent conversion coefficients for the recently recommended radiation protection quantities and a large number of fluence response functions for recently developed or improved detectors, as well as over 200 new spectra.
Download or read book Development of a Semirad Detection System for High intensity Neutron Radiation written by F. C. Riggin and published by . This book was released on 1967 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design, fabrication and testing of a detection system to measure pulses of high intensity neutron radiation is discussed. The system includes a neutron detecting component operating on the SEMIRAD principle and a 'stretcher' amplifier component capable of accepting the output pulse from the detector, shaping and amplifying the pulse so that the time-integral of the pulse waveform is proportional to the neutron dose. The system was made to operate over the temperature range of -28C to +65C by modification of the detector design to permit constant vac-ion pumping even during burst time. This was considered necessary because of the hydrogenous liner outgassing as a result of elevated operating temperatures as well as the high intensity neutron pulses. The design goal of a unity gamma to neutron response ratio was achieved for fission spectrum neutrons. The amplifier itself generates a noise signal which is proportional to the incident burst yield and should be operated remotely from the detector (20 to 40 ft. cable lengths) and shielded if possible. Sufficient radiation hardness was demonstrated in the selection of amplifier components from exposure of one 'stretcher' amplifier to a total dose of 26,600 rads with no detectable change in operability. (Author).
Download or read book 14 MeV Neutron Generator Used as a Thermal Neutron Source written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most important applications of the general purpose Monte Carlo N-Particle (MCNPS and MCNPX) codes is neutron shielding design. We employed this method to simulate the shield of a 14-MeV neutron generator used as a thermal neutron source providing an external thermal neutron beam for testing large area neutron detectors developed for diffraction studies in biology and also useful for national security applications. Nuclear reactors have been the main sources of neutrons used for scientific applications. In the past decade, however, a large number of reactors have been shut down, and the importance of other, smaller devices capable of providing neutrons for research has increased. At Brookhaven National Laboratory a moderated Am-Be neutron source with shielding is used for neutron detector testing. This source is relatively weak, but provides a constant flux of neutrons, even when not in use. The use of a 14 MeV energized neutron generator, with an order of magnitude higher neutron flux has been considered to replace the Am-Be source, but the higher fast neutron yield requires a more careful design of moderator and shielding. In the present paper we describe a proposed shielding configuration based on Monte Carlo calculations, and provide calculated neutron flux and dose distributions. We simulated the neutron flux distribution of our existing Am-Be source surrounded by a paraffin thermalizer cylinder (radius of 17.8 cm), 0.8 mm cadmium, and borated polyethylene as biological shield. The thermal neutrons are available through a large opening through the polyethylene and cadmium. The geometrical model for the MCNPS and MCNPX2 simulations is shown in Fig. 1. We simulated the Am-Be source neutron energy distribution as a point source having an energy distribution of four discrete lines at 3.0 (37%), 5.0 (35%), 8.0 (20%) and 11.0 (8%) MeV energies. The estimated source strength based on the original specifications is 6.6 · 106 neutrons/sec. The simulation accurately predicts the measured thermal neutron flux at the collimator (Figure 2), thus providing validation for this method. Using MCNPX we simulated the neutron and photon dose distribution and also obtained a good agreement with the measured values. Having established a validated framework for the shield calculation we then scaled up the Am-Be arrangement to simulate the shielding required for the higher neutron energy and flux of the neutron generator ( -108 neutrodsec at 14 MeV). Given the physical dimensions of the generator we have chosen a cylindrical geometry, where the generator tube is placed vertically into a cylindrical thermalizer (25 cm paraffin) from above. The thermalizer is surrounded by 0.8 mm cadmium, and a cylindrical borated polyethylene shield. A cylindrical opening (radius of 7.6 cm) serves to direct the neutrons out towards the experimental area (on the right side). The initial model is shown in figure 3. The first goal of the calculations was to establish the minimal required radius of the biological shield. For this purpose we performed MCNPX neutron and photon dose distribution calculations by tallying the absorbed dose on a 200 x 200 cm mesh in the vertical center plane superimposed over the geometry. Figure 4. displays the neutron dose distribution along the central horizontal (X) axis. As observed from the figure, a shielding radius of -80 cm is sufficient to obtain a dose level of
