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Title: Ehrenfest Dynamics for Stopping Power Calculations.

Abstract

Abstract not provided.

Authors:
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1406854
Report Number(s):
SAND2016-10713C
648551
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: Proposed for presentation at the Charged Particle Transport Code Comparison Workshop 2016 held October 24-26, 2016 in Albuquerque, NM.
Country of Publication:
United States
Language:
English

Citation Formats

Baczewski, Andrew David. Ehrenfest Dynamics for Stopping Power Calculations.. United States: N. p., 2016. Web.
Baczewski, Andrew David. Ehrenfest Dynamics for Stopping Power Calculations.. United States.
Baczewski, Andrew David. Sat . "Ehrenfest Dynamics for Stopping Power Calculations.". United States. doi:. https://www.osti.gov/servlets/purl/1406854.
@article{osti_1406854,
title = {Ehrenfest Dynamics for Stopping Power Calculations.},
author = {Baczewski, Andrew David},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Oct 01 00:00:00 EDT 2016},
month = {Sat Oct 01 00:00:00 EDT 2016}
}

Conference:
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  • Abstract not provided.
  • More precise stopping power models for use in ICF target design need to be developed. The light ion beam ICF program is now moving into a phase where ad hoc scaling of certain key physics parameters in the stopping power models is no longer sufficient. Our goal is to predict ion ranges in ICF targets to within about 10 to 20%. A verified stopping power model is also essential in diagnosing target irradiation intensities; such data can only be inferred by target response. Presently, our area of primary concern involves calculating the stopping power of the bound electrons of partiallymore » ionized atoms. One bound electron stopping power model that we are investigating uses the local oscillator model along with Hartree-Fock-Slater atomic charge density profiles to calculate I(Z,q,E), a generalized average ionization potential for the target electrons. This method is being studied systematically to look for deficiencies in the underlying physics model, especially at low projectile velocities. Another procedure uses the Generalized Oscillator Strength model to calculate the bound electron stopping. Experimental measurements of enhanced stopping power in ICF plasmas at the 0.3-TW/cm/sup 2/ level have been reported by the Naval Research Laboratory. Further experiments at Sandia are aimed at extending this data base both to higher ionization states and to higher-Z targets using a 1.2-TW/cm/sup 2/ proton beam on the PROTO-I accelerator.« less
  • The kinetic approach to stopping power calculations is explored within the framework of the binary encounter approximation by comparing two different stopping power definitions which take into account the kinetic motion of target particles. The definitions are {sigma}{sub max} {l_angle}{Delta}E{r_angle} and {sigma}{sub max} {l_angle}(u/v{sub 1}) {Delta}E{r_angle} where {sigma}{sub max}, is the cross-sectional area for non-adiabatic encounters, {Delta}E is the energy lost by the projectile per encounter, u is the relative projectile/target-particle speed, and v{sub 1} is the speed of the projectile. The average is taken over the velocity distribution of the target particles and over the encounter cross section. Amore » comparison of calculations using the two definitions with experimental data will be reported for simple targets.« less
  • More-precise stopping-power models for use in ICF target design need to be developed. The ion-driven ICF program is now moving into a phase where ad hoc scaling of certain key physics parameters in the stopping-power models is no longer sufficient. Our goal is to predict ion ranges in ICF targets to within about 10%. A verified stopping-power model is also essential in diagnosing target-irradiation intensities; such data can only be inferred by target response. Presently, our area of primary concern involves calculating the stopping power of the bound electrons of partially ionized atoms. One bound-electron stopping-power model that we aremore » investigating uses the free-electron-gas model along with Hartree-Fock-Slater atomic charge-density profiles to calculate I(Z,q,E), a generalized average ionization potential for the target electrons. This method is being systematically studied to look for deficiencies in the underlying physics model, especially at low projectile velocities. Another procedure uses the Generalized Oscillator Strength model to calculate the bound-electron stopping. Experimental measurements of enhanced stopping power in ICF plasmas at the .3 TW/cm/sup 2/ level have been reported by the Naval Research Laboratories. Further experiments at Sandia are aimed at extending this data base both to higher ionization states and to higher-Z targets using a 1.2 TW/cm/sup 2/ proton beam on the PROTO-I accelerator.« less
  • The prospects for obtaining better theoretical calculations of experimentally interesting electron interaction effects, over a wide range of electron energies, are now considerably improved through the development of models for valence electron excitation in simple insulators and through the availability of theoretical atomic generalized oscillator strengths for inner shell electron excitation in several low-Z atomic systems. The way in which this information may be used to calculate mean free paths, stopping powers, and electron slowing-down spectra in Al metal and the insulator Al$sub 2$O$sub 3$ is briefly described. (auth)