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Book Measurement of Neutron Flux and Spectra for Physical and Biological Applications

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:

Book Study of Scattered Background Neutron in NIF and Time of Flight TOF to Measure Neutron

Download or read book Study of Scattered Background Neutron in NIF and Time of Flight TOF to Measure Neutron written by M. Moran and published by . This book was released on 2005 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Some of the planned core diagnostics for National Ignition Facility (NIF) will use neutron time-of-flight (TOF) spectroscopy techniques to gather information for primary neutron yield measurement or neutron imaging. This technique has been widely and routinely used at other laser facilities including Nova and Omega. TOF methods will also be used to observe target fuel areal density {rho}R (radial integral of density) via measuring the number of primary 14.1 MeV neutrons that are down-scattered to lower energies by nuclear collisions inside the compressed target core. The substantially larger target chamber size and higher neutron yield for NIF raises issues related to the large number of scattered neutrons produced by high yield deuterium-tritium (D-T) shots at NIF. The effect of primary neutrons scattered by the walls of the massive target chamber and structures both inside and outside the chamber will contribute a significant scattered background signal when trying to determine the number of neutrons down-scattered from the target core. The optimum detector locations outside the target chamber or target bay wall will be proposed. Appropriate collimators at the chamber port and the bay wall (between the neutron source at target chamber center (TCC) and detector) that maximize detection of signal neutrons while minimizing the background from scattered neutrons and neutron induced gamma rays will also be presented.

Book National Ignition Facility NIF Neutron Time of flight nTOF Measurements

Download or read book National Ignition Facility NIF Neutron Time of flight nTOF Measurements written by and published by . This book was released on 2010 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first three of eighteen neutron time-of-flight (nTOF) channels have been installed at the National Ignition Facility (NIF). The role of these detectors includes yield, temperature, and bang time measurements. This article focuses on nTOF data analysis and quality of results obtained for the first set of experiments to use all 192 NIF beams. Targets produced up to 2 x 101° 2.45-MeV neutrons for initial testing of the nTOF detectors. Differences in neutron scattering at the OMEGA laser facility where the detectors were calibrated and at NIF result in different response functions at the two facilities. Monte Carlo modeling shows this difference. The nTOF performance on these early experiments indicates the nTOF system with its full complement of detectors should perform well in future measurements of yield, temperature, and bang time.

Book A Novel Method for Modeling the Neutron Time of Flight nTOF Detector Response in Current Mode to Inertial Confinement Fusion Experiments

Download or read book A Novel Method for Modeling the Neutron Time of Flight nTOF Detector Response in Current Mode to Inertial Confinement Fusion Experiments written by and published by . This book was released on 2013 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are several machines in this country that produce short bursts of neutrons for various applications. A few examples are the ZU+2010machine, operated by Sandia National Laboratories in Albuquerque, NMU+2020; the OMEGA Laser Facility at the University of Rochester in Rochester, NYU+00A7; and the National Ignition Facility (NIF) operated by the Department of Energy at Lawrence Livermore National Laboratory in Livermore, CaliforniaU+2021. They all incorporate neutron time of flight (nTOF) detectors which measure neutron yield, and the shapes of the waveforms from these detectors contain germane information about the plasma conditions that produce the neutrons. However, the signals can also be %E2%80%9Cclouded%E2%80%9D by a certain fraction of neutrons that scatter off structural components and also arrive at the detectors, thereby making analysis of the plasma conditions more difficult. These detectors operate in current mode - i.e., they have no discrimination, and all the photomultiplier anode charges are integrated rather than counted individually as they are in single event counting. Up to now, there has not been a method for modeling an nTOF detector operating in current mode. MCNPU+2010PoliMiU+F0D1was developed in 2002 to simulate neutron and gammaU+2010ray detection in a plastic scintillator, which produces a collision data output table about each neutron and photon interaction occurring within the scintillator; however, the postU+2010processing code which accompanies MCNPU+2010PoliMi assumes a detector operating in singleU+2010event counting mode and not current mode. Therefore, the idea for this work had been born: could a new postU+2010processing code be written to simulate an nTOF detector operating in current mode? And if so, could this process be used to address such issues as the impact of neutron scattering on the primary signal? Also, could it possibly even identify sources of scattering (i.e., structural materials) that could be removed or modified to produce %E2%80%9Ccleaner%E2%80%9D neutron signals? This process was first developed and then applied to the axial neutron time of flight detectors at the ZU+2010Facility mentioned above. First, MCNPU+2010PoliMi was used to model relevant portions of the facility between the source and the detector locations. To obtain useful statistics, variance reduction was utilized. Then, the resulting collision output table produced by MCNPU+2010PoliMi was further analyzed by a MATLAB postprocessing code. This converted the energy deposited by neutron and photon interactions in the plastic scintillator (i.e., nTOF detector) into light output, in units of MeVee%D1%84 (electron equivalent) vs time. The time response of the detector was then folded into the signal via another MATLAB code. The simulated response was then compared with experimental data and shown to be in good agreement. To address the issue of neutron scattering, an %E2%80%9CIdeal Case, %E2%80%9D (i.e., a plastic scintillator was placed at the same distance from the source for each detector location) with no structural components in the problem. This was done to produce as %E2%80%9Cpure%E2%80%9D a neutron signal as possible. The simulated waveform from this %E2%80%9CIdeal Case%E2%80%9D was then compared with the simulated data from the %E2%80%9CFull Scale%E2%80%9D geometry (i.e., the detector at the same location, but with all the structural materials now included). The %E2%80%9CIdeal Case%E2%80%9D was subtracted from the %E2%80%9CFull Scale%E2%80%9D geometry case, and this was determined to be the contribution due to scattering. The time response was deconvolved out of the empirical data, and the contribution due to scattering was then subtracted out of it. A transformation was then made from dN/dt to dN/dE to obtain neutron spectra at two different detector locations.

Book Summary of Neutron Measurement Methods

Download or read book Summary of Neutron Measurement Methods written by Herman Lunden Miller and published by . This book was released on 1962 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Tests and Calibration of the NIF Neutron Time of Flight Detectors

Download or read book Tests and Calibration of the NIF Neutron Time of Flight Detectors written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The National Ignition Facility (NIF) Neutron Time of Flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD* implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 109 to 2 x 1019. The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 m and 20 m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE). Operational tests of the NTOF detectors were performed on several facilities including the OMEGA laser at LLE and the Titan laser at Lawrence Livermore National Laboratory (LLNL). Neutron calibrations were carried out on the OMEGA laser. Results of the NTOF detectors tests and calibration will be presented. *(D = deuterium, T = tritium, H = hydrogen).

Book Measurement of Neutron Flux and Spectra for Physical and Biological Applications

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:

Book Use of an On line Computer in Neutron Time of flight Measurements

Download or read book Use of an On line Computer in Neutron Time of flight Measurements written by H. T. Heaton and published by . This book was released on 1970 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper describes the on-line data handling system at the NBS Electron Linear Accelerator facility as it is used for measuring neutron total cross sections by time-of-flight techniques.(Author).

Book Neutron Time of flight Spectrometer for Laser fusion Experiments

Download or read book Neutron Time of flight Spectrometer for Laser fusion Experiments written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The basic concept of a time-of-flight spectrometer is illustrated. The spectrometer described can measure 14.1-MeV neutrons coming directly from the D-T plasma and also neutrons scattered by the air or ground or other structures within the vicinity of the flight path. (MOW).

Book The Time of Flight Method Applied to 2 37 MeV Neutrons

Download or read book The Time of Flight Method Applied to 2 37 MeV Neutrons written by Tung-Hong Hsu and published by . This book was released on 1964 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Neutron Generators for Analytical Purposes

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.

Book Compilation of Resolutions and Intensities of Slow Neutron Inelastic Scattering Time of flight Instruments

Download or read book Compilation of Resolutions and Intensities of Slow Neutron Inelastic Scattering Time of flight Instruments written by Robert M. Brugger and published by . This book was released on 1966 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book p n and d n Time of flight Experiments

Download or read book p n and d n Time of flight Experiments written by and published by . This book was released on 1967 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: