EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Analysis of the Neutron Time of flight Spectra from Inertial Confinement Fusion Experiments

Download or read book Analysis of the Neutron Time of flight Spectra from Inertial Confinement Fusion Experiments written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For a long time, neutron time-of-flight diagnostics been used to characterize the neutron spectrum produced by inertial confinement fusion experiments. The primary diagnostic goals are to extract the d+t→n+[alpha] (DT) and d+d→n+3He (DD) neutron yields and peak widths, and the amount DT scattering relative to its unscattered yield, which is also known as the down-scatter ratio (DSR). These quantities are used to infer yield weighted plasma conditions, such as ion temperature (Tion) and cold fuel areal density. We explain such novel methodologies used to determine neutron yield, apparent Tion and DSR.

Book Characterizing a Neutron Energy Spectrum Using a forward Edge Neutron Time of flight Spectroscopy Technique

Download or read book Characterizing a Neutron Energy Spectrum Using a forward Edge Neutron Time of flight Spectroscopy Technique written by Jeffrey S. Spear and published by . This book was released on 2005 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Neutron and Gamma Time of flight Measurements in Inertial Confinement Fusion Experiments

Download or read book Neutron and Gamma Time of flight Measurements in Inertial Confinement Fusion Experiments written by Zaarah L. Mohamed and published by . This book was released on 2021 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This work includes the study of various nuclear processes relevant to inertial confinement fusion (ICF) plasmas and big bang nucleosynthesis via experiments performed at the OMEGA laser facility. Neutron and gamma time-of-flight detectors were used to determine various quantities of interest in cryogenic and room temperature implosions. In particular, xylene neutron time-of-flight (nTOF) detectors were used to determine areal densities from backscattered neutrons for OMEGA cryogenic experiments using a forward fit analysis. This analysis was extended to a recently deployed second nTOF line of sight (LOS) on OMEGA. The presence of two nTOF LOS enables a comparison of two measurements to study implosion symmetry, however, these two measurements still leave a lack of coverage around the target chamber which makes it difficult to infer the 3D shape of the areal density. This analysis can easily be extended to additional nTOF lines of sight in the future. The original xylene nTOF detector was also used to infer properties of the 5He ground state and first excited state via a simple wave-function amplitude analysis of neutron spectra from warm TT implosions. These quantities are particularly interesting because of their relationship to the gamma spectrum produced by DT fusion and additionally because the TT neutron spectrum is a background observed in the neutron spectra produced on cryogenic implosions. The ground state mass inferred via forward fit agrees with the accepted value [Audi et al., Nucl. Phys. A 729 (2003)], but the lifetime inferred here is about 70% longer than the accepted value [Wong, Anderson, & McClure, Nucl. Phys. 71 (1965)]. The mass and width of the first excited state were also inferred and compared to previously reported values, though there is a wide spread in the previously reported values. Cherenkov detectors were used to study gamma rays from the reactions D(T,5He)[gamma], H(D,3He)[gamma], and H(T,4He)[gamma] at low energies. The measurements detailed in this work result in a DT gamma-to-neutron branching ratio of (8.42 ł 2.84) × 10-5 measured at a center-of-mass (CM) energy of 19 ł 2 keV. This branching ratio is a factor of 2 larger than the branching ratio previously inferred on an ICF platform [Kim et al., Phys. Rev. C 85 (2012)], however, the error bars on the two measurements overlap. Considering a recent measurement of the DT gamma spectrum [Horsfield et al., Phys. Rev. C. 104 (2021)], the branching ratio measurement detailed in this work also appears to be in agreement with accelerator measurements [Cecil & Wilkinson, Phys. Rev. Lett. 53 (1984); Morgan et al., Phys. Rev. C. 33 (1986)] that isolated the ground state DT gamma. S factors for H(D,3He)[gamma] and H(T,4He)[gamma] were determined at low energies (ECM=16-37 keV). The inferred H(D,3He)[gamma] S factor appears to agree with accelerator data. The H(T,4He)[gamma] S factor inferred from one detector with a relatively high gamma energy threshold appears to be 25-70% larger than an evaluated S factor determined by including accelerator data at higher CM energies [Canon et al., Phys. Rev. C 65 (2002)], however, only two accelerator data points currently exist for comparison at these low energies and these two accelerator data points are in reasonable agreement with the S factors inferred using the high threshold detector as detailed in this work. Another detector with a very low minimum gamma energy threshold was also used to study the H(T,4He)[gamma] S factor. This detector inferred significantly higher values for the H(T,4He)[gamma] S factor, but this particular measurement is thought to be contaminated by detection of neutron-induced gammas from remaining shell material. These time-of-flight gamma measurements require some assumptions concerning the gamma spectrum from each reaction in order to infer branching ratios or S factors. This is not ideal, however, traditional pulse height gamma detection cannot be used for detection of fusion gammas in ICF experiments due to the short time scales involved. Two potential designs are discussed for a true gamma spectrometer intended for operation at ICF facilities"--Pages ix-x.

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:

Book Measurements of the Neutron Emission Spectra from Spheres of N O W 235U 238U and 239Pu Pulsed by 14 MeV Neutrons

Download or read book Measurements of the Neutron Emission Spectra from Spheres of N O W 235U 238U and 239Pu Pulsed by 14 MeV Neutrons written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Inspired by new detector instrumentation that is insensitive to gamma-ray background and improved deuteron-beam bunching and sweeping of the ICT accelerator, we have measured the high-energy (2 less than E/sub n/ less than 15 MeV) neutron emission spectra from spherical targets of nitrogen, oxygen, tungsten, 235U, 238U, and 239Pu. The targets were pulsed at the center by a nominal 14-MeV neutron source at the LLL time-of-flight facility. The neutron source was obtained from the T(d, n)4He reaction with a pulsed 400-keV deuteron beam, produced by the LLL ICT accelerator. Collimated scintillation detectors at 26° and 120° with respect to the deutron beam and at flight paths from 7.5-9.8 m recorded the neutron time-of-flight spectra.

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Incident Spectrum Determination for Time of flight Neutron Powder Diffraction Data Analysis

Download or read book Incident Spectrum Determination for Time of flight Neutron Powder Diffraction Data Analysis written by and published by . This book was released on 1998 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate characterization of the incident neutron spectrum is an important requirement for precise Rietveld analysis of time-of-flight powder neutron diffraction data. Without an accurate incident spectrum the calculated model for the measured relative intensities of individual Bragg reflections will possess systematic errors. We describe a method for obtaining an accurate numerical incident spectrum using data from a transmitted beam monitor.

Book Neutron Time Of Flight Spectroscopy Classic Reprint

Download or read book Neutron Time Of Flight Spectroscopy Classic Reprint written by John R. D. Copley and published by Forgotten Books. This book was released on 2018-09-26 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Neutron Time-of-Flight Spectroscopy Fig. 1. Schematic plan view of a simple time-of-flight spectrom eter. The letters R, M, C, S, and D denote the reactor, monochromator, chopper, sample and detectors, respectively. Important distances are indicated. In practice, the slots in the (fermi) chopper are curved in order to optimize its transmission. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Book Neutron Time of flight Methods

Download or read book Neutron Time of flight Methods written by European-American Nuclear Data Committee and published by . This book was released on 1961 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book NEUTRON SPECTRA IN BULK MEDIA BY TIME OF FLIGHT

Download or read book NEUTRON SPECTRA IN BULK MEDIA BY TIME OF FLIGHT written by and published by . This book was released on 1965 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Time of Flight Measurements of Neutron Spectra in a Graphite Uranium Lattice at Different Temperatures

Download or read book Time of Flight Measurements of Neutron Spectra in a Graphite Uranium Lattice at Different Temperatures written by Atomic Energy Research Establishment (Harwell, England). Nuclear Physics Division and published by . This book was released on 1961 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: