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Title: Using multiple neutron time of flight detectors to determine the hot spot velocity

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.5039372· OSTI ID:1545515

An important diagnostic value of a shot at the National Ignition Facility is the resultant center-of-mass motion of the imploding capsule. This residual velocity reduces the efficiency of converting laser energy into plasma temperature. A new analysis method extracts the effective hot spot motion by using information from multiple neutron time-of-flight (nToF) lines-of-sight (LoSs). This technique fits a near Gaussian spectrum to the nToF scope traces and overcomes reliance on models to relate the plasma temperature to the mean energy of the emitted neutrons. This method requires having at least four nToF LoSs. The results of this analysis will be compared to an approach where each LoS is analyzed separately and a model is employed to infer the mean energy of the emitted neutrons

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
AC52-07NA27344
OSTI ID:
1545515
Alternate ID(s):
OSTI ID: 1477910
Journal Information:
Review of Scientific Instruments, Vol. 89, Issue 10; Conference: 22. Topical Conference on High-Temperature Plasma Diagnostics, San Diego, CA (United States), Apr. 2018; ISSN 0034-6748
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 28 works
Citation information provided by
Web of Science

References (12)

Progress towards ignition on the National Ignition Facility journal August 2011
Progress towards ignition on the National Ignition Facility journal July 2013
Metrics for long wavelength asymmetries in inertial confinement fusion implosions on the National Ignition Facility journal April 2014
Neutron spectrometry—An essential tool for diagnosing implosions at the National Ignition Facility (invited) journal October 2012
Relativistic calculation of fusion product spectra for thermonuclear plasmas journal November 1998
Engineering architecture of the neutron Time-of-Flight (nToF) diagnostic suite at the National Ignition Facility conference September 2014
A fused silica Cherenkov radiator for high precision time-of-flight measurement of DT γ and neutron spectra (invited) journal October 2018
Uncertainty analysis of response functions and γ-backgrounds on T ion and t 0 measurements from Cherenkov neutron detectors at the National Ignition Facility (NIF) journal October 2018
Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments journal November 2015
The effect of turbulent kinetic energy on inferred ion temperature from neutron spectra journal July 2014
Diagnosing inertial confinement fusion gamma ray physics (invited) journal October 2010
Interpreting inertial fusion neutron spectra journal February 2016

Cited By (3)

Velocity correction for neutron activation diagnostics at the NIF journal October 2018
A fused silica Cherenkov radiator for high precision time-of-flight measurement of DT γ and neutron spectra (invited) journal October 2018
Neutron backscatter edge: A measure of the hydrodynamic properties of the dense DT fuel at stagnation in ICF experiments journal January 2020

Figures / Tables (6)