Download or read book A High energy Neutron Flux Spectra Measurement Method for the Spallation Neutron Source written by Nicholas Patrick Luciano and published by . This book was released on 2012 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this work was to develop a foil activation method to measure high-energy (1--120 MeV) neutron flux spectra at the Spallation Neutron Source by researching the scientific literature, assembling an experimental apparatus, performing experiments, analyzing the results, and refining the technique based on experience. The primary motivation for this work is to provide a benchmark for the neutron source term used in target station and shielding simulations Two sets of foil irradiations were performed, one at the ARCS beamline and one at the POWGEN beamline. The gamma radiation of the foil activation products was measured with a high purity germanium gamma-ray spectrometer, and the product reaction rates during irradiation were quantified. Corrections, such as self-shielding factors, were applied to the measurements to account for particular effects. The corrected measurement data, along with calculated response functions and an initial guess spectrum, were input to the MAXED neutron spectrum unfolding computer code. MAXED uses the maximum entropy method to unfold an output spectrum that is the minimally modied guess spectrum consistent with the measurement data. The foil irradiation and subsequent analysis from the ARCS spectrum produced a reasonable neutron spectrum, which noticeably differed from the initial guess spectrum. This measurement is regarded as consistent, but yet unverified. The gamma-ray spectrum of the foil irradiation at the POWGEN beamline showed no high-energy activation. This is regarded as an experimental error, and no conclusions can be drawn about the high-energy neutron spectrum. Future foil irradiations are planned to verify and expand the neutron spectrum measurements.
Download or read book Measurement of Neutron Flux and Spectra for Physical and Biological Applications written by National Committee on Radiation Protection and Measurements (U.S.) and published by . This book was released on 1960 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Neutron Flux and Spectra for Physical and Biological Applications written by National Committee on Radiation Protection and Measurements (U.S.) and published by . This book was released on 1960 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Neutron Flux and Spectra for Physical and Biological Applications written by United States. National Committee on Radiation Protection and Measurements and published by . This book was released on 1960 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Neutron Flux and Spectra for Physical and Biological Applications written by National Committee on Radiation Protection and Measurements (U.S.) and published by . This book was released on 1960 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Two plate Method of Measuring Fast Neutron Energy Spectra when the Direction of the Incident Neutrons Cannot be Determined written by John E. Evans and published by . This book was released on 1952 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monitoring Method for Neutron Flux for a Spallation Target in an Accelerator Driven Sub critical System Supported by Strategic Priority Research Program of Chinese Academy of Sciences XDA03010000 and XDA03030000 and the National Natural Science Foundation of China 91426301 written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this paper, we study a monitoring method for neutron flux for the spallation target used in an accelerator driven sub-critical (ADS) system, where a spallation target located vertically at the centre of a sub-critical core is bombarded vertically by high-energy protons from an accelerator. First, by considering the characteristics in the spatial variation of neutron flux from the spallation target, we propose a multi-point measurement technique, i.e. the spallation neutron flux should be measured at multiple vertical locations. To explain why the flux should be measured at multiple locations, we have studied neutron production from a tungsten target bombarded by a 250 MeV-proton beam with Geant4-based Monte Carlo simulations. The simulation results indicate that the neutron flux at the central location is up to three orders of magnitude higher than the flux at lower locations. Secondly, we have developed an effective technique in order to measure the spallation neutron flux with a fission chamber (FC), by establishing the relation between the fission rate measured by FC and the spallation neutron flux. Since this relation is linear for a FC, a constant calibration factor is used to derive the neutron flux from the measured fission rate. This calibration factor can be extracted from the energy spectra of spallation neutrons. Finally, we have evaluated the proposed calibration method for a FC in the environment of an ADS system. The results indicate that the proposed method functions very well.
Download or read book A Method for Intercalibrating of Neutron Sources with Different Spectra written by A. Wattenberg and published by . This book was released on 1950 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Neutron Flux Spectra in a Tungsten Benchmark by Neutron Foil Activation Method written by Cezar Ciprian Negoita and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elements of Slow Neutron Scattering written by J. M. Carpenter and published by Cambridge University Press. This book was released on 2015-09-24 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive and up-to-date introduction to the fundamental theory and applications of slow-neutron scattering.
Download or read book A New Technique for the Measurement of Neutron Energy Spectra written by George Robert Keepin and published by . This book was released on 1949 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoneutron Sources written by B. W. Sargent and published by . This book was released on 1946 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Accelerator Driven System at Kyoto University Critical Assembly written by Cheol Ho Pyeon and published by Springer. This book was released on 2021-03-20 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book is a unique compilation of experimental benchmark analyses of the accelerator-driven system (ADS) at the Kyoto University Critical Assembly (KUCA) on the most recent advances in the development of computational methods. It is devoted especially to nuclear engineers and scientists. Readers will find a detailed description of advanced measurement techniques and calculation methodologies for the ADS with 14 MeV neutrons and high-energy neutrons (with combined use of 100 MeV protons and Pb-Bi target) at KUCA. Additionally, experimental results of nuclear transmutation of minor actinides by ADS and at a critical state are included. Readers also have access to benchmarks of specific ADS experiments with raw data in the Appendix. The book is a valuable resource for the ADS experiments at KUCA which are globally recognized as both static and kinetic studies from the point of view of fundamental research.
Download or read book Status of the Dosimetry for the Radiation Effects Research Foundation DS86 written by National Research Council and published by National Academies Press. This book was released on 2001-10-04 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Committee on Dosimetry for the Radiation Effects Research Foundation (RERF) was set up more than a decade ago at the request of the U.S. Department of Energy. It was charged with monitoring work and experimental results related to the Dosimetry System 1986 (DS86) used by RERF to reconstruct the radiation doses to the survivors in Hiroshima and Nagasaki. At the time it was established, DS86 was believed to be the best available dosimetric system for RERF, but questions have persisted about some features, especially the estimates of neutrons resulting from the Hiroshima bomb. This book describes the current situation, the gamma-ray dosimetry, and such dosimetry issues as thermal-neutron discrepancies between measurement and calculation at various distances in Hiroshima and Nagasaki. It recommends approaches to bring those issues to closure and sets the stage for the recently convened U.S. and Japan Working Groups that will develop a new dosimetry for RERF. The book outlines the changes relating to DS86 in the past 15 years, such as improved numbers that go into, and are part of, more sophisticated calculations for determining the radiations from bombs that reach certain distances in air, and encourages incorporation of the changes into a revised dosimetry system.
Download or read book Neutron Spectrum Measurements for Radiation Protection Purposes written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy spectra of low-intensity neutron sources used for calibrating personnel neutron dose-rate meters and dosimeters and for characterizing the neutron fields to which personnel are exposed were measured. Several detector-analyzer systems that will measure in the energy range 50 keV to 20 MeV at intensities from 10−1 to 105 n/cm2-s are described. The systems include NE213 and stilbene organic scintillators as well as H2, 3He, and CH4 proportional counters. Also described are pulse-height analysis and pulse-shape discrimination systems. An unfolding code, NUTSPEC, reduces the pulse-height data to an absolute differential neutron flux phi(E) for the above detectors. The code uses a derivative unfolding method for the scintillation detectors, and for the proportional counters it calculates a response matrix and uses an iterative unfolding method to determine phi(E). The unfolded flux distribution combined with published conversion factors produces differential neutron dose-equivalent and kerma rates. Spectral segments obtained with different detectors from several measurements merge into a single differential flux spectrum over the range 50 keV to 20 MeV, together with the corresponding differential kerma and neutron dose-equivalent distributions. Also reported are spectrum measurements near 252Cf and 238PuBe sources with various moderators.
Download or read book Neutron Spectrum Determinations at Low Flux Levels written by Paul Kruger and published by . This book was released on 1960 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron flux measurements have been made (1)2 of low-level neutron sources present in several types of neutron-producing facilities. The flux levels or distribution of thermal, epithermal, and fast neutrons have been measured in radioisotope sources, spent fuel element gamma irradiation facilities, and electron linear accelerators. Sensitivities greater than 1 neutron per sq cm per sec have been achieved for thermal neutrons. Neutron flux measurements may be made by several methods (2). Foil activation (3) is a convenient and simple technique. The foils containing materials of known cross-section are exposed to the neutrons, and the flux determinations are made by measurement of the induced activities in the irradiated foils. This technique is widely used for measuring neutron fluxes and spectra in nuclear reactors and critical facilities where the neutron fluxes are large (106 to 1014 neutrons per sq cm per sec). To measure neutron fluxes of smaller magnitude, such as those found in isotope sources, gamma irradiation facilities, or outside reactor shielding (1⁄4106 neutrons per sq cm per sec), special foil dosimetry techniques or counting methods are required to obtain sufficient sensitivity for the radioactivity measurements. The theoretical and experimental considerations for neutron detectors of high sensitivity and several programs in which these detectors were used are discussed.
