Download or read book Absolute Measurement of DT Neutron Yield on the National Ignition Facility written by and published by . This book was released on 2011 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measuring the Absolute DT Neutron Yield Using the Magnetic Recoil Spectrometer at OMEGA and the NIF written by and published by . This book was released on 2012 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

Download or read book An Improved Method for Measuring the Absolute DD Neutron Yield and Calibrating Neutron Time of flight Detectors in Inertial Confinement Fusion Experiments written by Caleb Joseph Waugh and published by . This book was released on 2014 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the establishment of nuclear physics in the early 1900's and the development of the hydrogen bomb in the 1950's, inertial confinement fusion (ICF) has been an important field in physics. Funded largely though the U.S. National Nuclear Security Agency (NNSA), the Laboratory for Laser Energetics (LLE), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratory (LLNL) have advanced ICF as a platform for stockpile stewardship and weapons physics, but also have contributed to basic science in high energy density regimes and for pursuing fusion an energy source. One of the primary goals of the ICF research program is to produce a thermonuclear burn in an ICF capsule where the power balance of the reaction is net positive. This criterion is often referred to as ignition. One of the most common metrics for gauging progress towards ignition in an ICF implosion is the ITFX parameter (similar to the Lawson Criterion) and is primarily a function of the implosion areal density (pR) and fusion yield. An ITFX value greater than one indicates net energy production. In deuterium/tritium fuel mixtures the yield is determined by measuring the reactant 14.0 MeV neutrons. Subsequently, the ability to obtain highly accurate absolute neutron yield measurements is vital to determining the ITFX and hence progress toward ignition. Although ignition implosions all use deuterium/tritium fuel mixes, other capsule fuel mixes such as pure deuterium and deuterium/helium 3 are also used to improve understanding of capsule performance. At the LLE and LLNL, neutron time-of-flight (nTOF) detectors routinely measure the absolute neutron yield from laser-driven ICF implosions. Although originally calibrated through a series of cross-calibrations with indium and copper neutron activation systems, an alternative method has been developed for measuring the DDn yield that provides a more accurate calibration by directly calibrating nTOF in situ to CR-39 range filter (RF) proton detectors. A neutron yield can be inferred from the CR-39 RF proton measurement since the DD proton and DD neutron branching ratio is well characterized and close to unity. By obtaining highly accurate DDp yields from a series of exploding pusher campaigns on OMEGA, an excellent absolute DDn yield measurement was obtained and used to calibrate the 3m nTOF detector. Data obtained suggest the existing OMEGA nTOF calibration coefficient to be low by 9.0 1.5 % based on the inferred CR-39 DD neutron yield. In addition, comparison across multiple exploding pusher campaigns indicate that significant reduction in charged particle flux anisotropies can be achieved on shots where capsule bang time occurs significantly (on the order of 500ps) after the end of the laser pulse. This is important since the main source of error in the RF DDp yield measurement is due to particle flux anisotropies. Results indicate that the CR-39 RF/nTOF in situ calibration method can serve as a valuable platform for measuring the DDn yield from ICF implosions and for calibrating and reducing the uncertainty of calibration coefficients of nTOF detector systems on OMEGA and other larger facilities such as the National Ignition Facility (NIF).

Download or read book The NIF 4 5 m NTOF Detectors written by and published by . This book was released on 2012 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator/photodetector neutron-time-of-flight (nTOF) detectors for measuring DD and DT neutron yields. The detectors provided consistent neutron yield benchmarks from below 1E9 (DD) to nearly 1E15 (DT). The detectors demonstrated DT yield measurement precisions better than 5%, but the absolute accuracy relies on cross calibration with independent measurements of absolute neutron yield. The 4.5-m nTOF data have provided a useful testbed for testing improvements in nTOF data processing, especially with respect to improving the accuracies of the detector impulse response functions. The resulting improvements in data analysis methods have produced more accurate results. In summary, results from the NIF 4.5-m nTOF detectors have provided consistent measurements of DD and DT neutron yields from laser-fusion implosions.

Download or read book On the Absolute Calibration of a DT Fusion Neutron Yield Diagnostic written by and published by . This book was released on 2012 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Magnetic Recoil Spectrometer for Measurements of the Absolute Neutron Spectrum at OMEGA and the NIF written by and published by . This book was released on 2013 with total page 43506 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, iontemperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

Download or read book Experimental Component Characterization Monte Carlo based Image Generation and Source Reconstruction for the Neutron Imaging System of the National Ignition Facility written by Carlos Andres Barrera and published by . This book was released on 2007 with total page 394 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 Absolute Neutron Flux Measurements of a D T Neutron Generator written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Absolute Calibration of the Neutron Yield Measurement on JT 60 Upgrade written by C. W. (and others). Barnes and published by . This book was released on 1991 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Absolute Measurement of Thermal Neutron Density written by H. L. Anderson and published by . This book was released on 1947 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Neutron Spectrum from the T t 2n Reaction with the National Ignition Facility written by and published by . This book was released on 2013 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Issues in Applied Analytical and Imaging Sciences Research 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 2773 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Applied, Analytical, and Imaging Sciences Research. The editors have built Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Applied, Analytical, and Imaging Sciences Research in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book Issues in Applied Analytical and Imaging Sciences Research 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-05-01 with total page 1217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Applied, Analytical, and Imaging Sciences Research: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Applied Analysis. The editors have built Issues in Applied, Analytical, and Imaging Sciences Research: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Applied Analysis in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Applied, Analytical, and Imaging Sciences Research: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book Low Energy Neutron Measurements for Ignition and Capture Cross Section Studies at the National Ignition Facility written by and published by . This book was released on 2013 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Imploded Capsule Fuel Temperature and Density Measurement by Energy Dependent Neutron Imaging written by M. J. Moran and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron imaging systems measure the spatial distribution of neutron emission from burning inertial confinement fusion (ICF) targets. These systems use a traditional pinhole geometry to project an image of the source onto a two-dimensional scintillator array, and a CCD records the resulting scintillation image. The recent history of ICF neutron images has produced images with qualities that have improved as the fusion neutron yields have increased to nearly 10{sup 14} neutrons. Anticipated future neutron yields in excess of 10{sup 16} at the National Ignition Facility and LMJ have raised the prospect of neuron imaging diagnostics which simultaneously probe several different characteristics of burning fusion targets. The new measurements rely on gated-image recording to select images corresponding to specific bands of neutron energies. Gated images of downscattered neutrons with energies from 5 to 8 MeV can emphasize regions of the target which contain DT fuel which is not burning. At the same time, gated images which select different portions of the 14-MeV spectral peak can produce spatial temperature maps of a burning target. Since the neutron production depends on the DT fuel density and temperature, simultaneous images of temperature and neutron emission can be combined to infer the an image of the source density using an Abel inversion method that is analogous to the method that has been used in x-ray imaging. Thus, with higher-yield sources, neutron imaging offers the potential to record simultaneously several critical features that characterize the performance of an ICF target: the neutron emission distribution, the temperature and density distributions, and the distribution of nonburning fuel within the target.

Download or read book Measurements of DT and DD Neutron Yields by Neutron Activation on TFTR written by and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 1012 to over 1018, and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants, and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma) accuracy of the measurements; also agreeing are yields from silicon foils using the ACTL library cross-section, while the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115In(n.n(prime)) {sup 115m}In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments.