Download or read book The Development of a High Count Rate Neutron Flux Monitoring Channel Using Silicon Carbide Semiconductor Radiation Detectors written by Mehdi Reisi Fard and published by . This book was released on 2006 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this dissertation, a fast neutron flux monitoring channel, which is based on the use of SiC semiconductor detectors is designed, modeled and experimentally evaluated as a power monitor for the Gas Turbine Modular Helium Reactors. A detailed mathematical model of the SiC diode detector and the electronic processing channel is developed using TRIM, MATLAB and PSpice simulation codes. The flux monitoring channel is tested at the OSU Research Reactor. The response of the SiC neutron-monitoring channel to neutrons is in close agreement to simulation results. Linearity of the channel response to thermal and fast neutron fluxes, pulse height spectrum of the channel, energy calibration of the channel and the detector degradation in a fast neutron flux are presented. Along with the model of the neutron monitoring channel, a Simulink model of the GT-MHR core has been developed to evaluate the power monitoring requirements for the GT-MHR that are most demanding for the SiC diode power monitoring system. The Simulink model is validated against a RELAP5 model of the GT-MHR. This dyanamic model is used to simulate reactor transients at the full power and at the start up, in order to identify the response time requirements of the GT-MHR. Based on the response time requirements that have been identified by the Simulink model and properties of the monitoring channel, several locations in the central reflector and the reactor cavity are identified to place the detector. The detector lifetime and dynamic range of the monitoring channel at the detector locations are calculated. The channel dynamic range in the GT-MHR central reflector covers four decades of the reactor power. However, the detector does not survive for a reactor refueling cycle in the central reflector. In the reactor cavity, the detector operates sufficiently long; however, the dynamic range of the channel is smaller than the dynamic range of the channel in the central reflector.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Damage in SiC Semiconductor Radiation Detectors in the GT MHR written by D. W. Miller and published by . This book was released on 2006 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a part of a U.S. Department of Energy Nuclear Engineering Research Initiative (NERI) project, we are evaluating the potential for using silicon carbide (SiC) semiconductor radiation detectors, operating in the pulse mode, as power monitors for gas turbine modular helium reactor (GT-MHR) [1]. Locations for the power monitors will be selected considering acceptable detector count rates and lifetimes. We have characterized the radiation environment at various locations in the GT-MHR, where detectors may be placed, in terms of the 1 MeV equivalent neutron flux in SiC (?eq, 1 MeV SiCTotal). Also, we have characterized the radiation field in beam part 1 (BP1) of the Ohio State University Research Reactor (OSURR) in these same terms, with the intent of correlating observed degradation of the SiC detectors in the OSURR to the degradation that can be expected for various detector locations in the GT-MHR. Comparing ?eq, 1 MeV, SiCTotal for the GT-MHR and for the OSURR, we conclude that SiC devices cannot be adequately tested in the characterization vessel in OSURR BP1 for the radiation damage that would be incurred over a refueling cycle for detectors placed in-core. Also, we note that the radiation environment in the OSURR BP1 is harder than the radiation environment in the GT-MHR.

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 Nuclear Science Abstracts written by and published by . This book was released on 1975-03 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book LCRE Neutron Sensor Development Program written by R. C. Harrison and published by . This book was released on 1964 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Effects of Mixed Neutron gamma Irradiation of Sic Neutron Power Monitors on Their Recorded Pulse Height Distribution and I V Curves written by Vijayalakshmi Krishnan and published by . This book was released on 2007 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: SiC radiation detectors are being developed for neutron detection in high radiation environment. The wide band gap and high radiation resistance compared to the other conventional semiconductors make it suitable for high radiation environment. In this thesis, the degradation of SiC diode neutron detectors in a mixed neutronlgamma ray radiation field has been evaluated. The degradation of the performance of the SiC detectors has been evaluated using a standard pulse height analysis counting chain with a charge sensitive preamplifier in the thermal neutron irradiation field. Experiments that are performed with different types of SiC detector packages in the thermal neutron field of the OSU Research Reactor (OSURR) are described. Based on the experiments, the response of the detectors to the thermal neutron is presented. Degradation of the detectors in the thermal neutron environment is evaluated in terms of dose and dose rate effect. A theoretical model of SiC diode detector is developed using MATLAB and TRIM software. The experimental and theoretical count rates for SiC diode detectors placed in a thermalized neutron environment are compared. Finally, the I-V characteristics of the diode are measured to confirm the degradation of the detectors.

Download or read book Transactions of the American Nuclear Society written by American Nuclear Society and published by . This book was released on 1965 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spent Fuel Monitoring with Silicon Carbide Semiconductor Neutron Gamma Detectors written by J. G. Seidel and published by . This book was released on 2006 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon carbide semiconductor radiation detectors have been demonstrated for neutron and gamma-ray monitoring of spent nuclear fuel. Neutrons and gamma rays were monitored simultaneously over a 2050-h period, resulting in a gamma dose of over 6000 Gy to the SiC detector. No changes in the neutron and gamma-ray sensitivity were observed as a result of the gamma-ray exposure. After the spent-fuel measurements, the absolute neutron sensitivity was determined in a standard neutron field, and the degree of gamma-ray and neutron spectrum overlap were determined through exposures in intense gamma ray fields. No overlap was observed for gamma-ray dose rates up to 100 G/h.

Download or read book Technical Impediments to a More Effective Utilization of Neutron Transmutation Doped Silicon for High power Device Fabrication written by D. R. Meyers and published by . This book was released on 1980 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a High Flux Neutron Radiation Detection System for In core Temperature Monitoring written by Thifhelimbilu Daphney Singo and published by . This book was released on 2012 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Level Neutron Flux Monitor for Reactor Use written by Robert V. Studley and published by . This book was released on 1962 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1971 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Application of Semiconductor Radiation Detectors to the Observation of Fast Neutrons written by E. L. Zimmerman and published by . This book was released on 1962 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several methods of utilizing a semiconductor radiation detector for neutron observations have been investigated. Techniques for the application of neutron-sensitive materials to detector surfaces have been developed and the resulting coated detectors have been evaluated as both thermal and threshold detectors. A "good geometry" proton-recoil spectrometer utilizing a semiconductor detector has been built and used to observe fast neutrons. An analytical study of this device resulted in a method which can accurately predict its response as a function of incident neutron energy., hydrogenous radiator thickness, and systm geometry. Good qualitative agreement was observed between the predicted and experimental response

Download or read book Nuclear Applications written by and published by . This book was released on 1967 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of a Fast Neutron Monitoring System Using Semiconductor Detectors written by Lawrence M. Epstein and published by . This book was released on 1966 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recommendations have been made for a solid state neutron monitor of maximum radiation endurance based on the use of low resistivity silicon counting diodes. Shallow diffused diodes of 10-20 ohm-cm p base silicon were used to obtain fission fragment spectra in-core after exposure to 4.6 x 10 to the 15th power nvt (greater than power 10 kev). Bias levels were 25 v maximum initially and 45 v maximum finally. Features of the radiation degradation were (a) a large increase in leakage current to greater than 100 microamperes, (b) a large decrease in a charge collection efficiency (about a factor of ten), (c) an improvement in ability to sustain bias without breakdown noise, and (d) a decrease in capacity. A voltage sensitive preamplifier based on an integrated circuit amplifier was used. It was designed also for radiation endurance and was virtually unaffected by exposure to 3 x 10 to the 13 power nvt. A number of preliminary measurements are reported using electron-irradiated low resistivity silicon solar cells as counters and californium 252 as a source of fission fragments. These experiments served to confirm the expected nature of the damage, and showed the lack of sensitivity to gamma background and to temperature changes. One diode each of GaAs and SiC were included in the first reactor tests but the good silicon results preempted any further work with other diodes.