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Title: Radiation transport in kinetic simulations and the influence of photoemission on electron current in self-sustaining discharges

Abstract

A kinetic description for electronic excitation of helium for principal quantum number n $$\leqslant $$ 4 has been included into a particle-in-cell (PIC) simulation utilizing direct simulation Monte Carlo (DSMC) for electron-neutral interactions. The excited electronic levels radiate state-dependent photons with wavelengths from the extreme ultraviolet (EUV) to visible regimes. Photon wavelengths are chosen according to a Voigt distribution accounting for the natural, pressure, and Doppler broadened linewidths. This method allows for reconstruction of the emission spectrum for a non-thermalized electron energy distribution function (EEDF) and investigation of high energy photon effects on surfaces, specifically photoemission. A parallel plate discharge with a fixed field (i.e. space charge neglected) is used to investigate the effects of including photoemission for a Townsend discharge. When operating at a voltage near the self-sustaining discharge threshold, it is observed that the electron current into the anode is higher when including photoemission from the cathode than without even when accounting for self-absorption from ground state atoms. As a result, the photocurrent has been observed to account for as much as 20% of the total current from the cathode under steady-state conditions.

Authors:
 [1];  [1];  [2];  [1];  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Univ. of Iowa, Iowa City, IA (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1340276
Alternate Identifier(s):
OSTI ID: 1339005
Report Number(s):
SAND-2016-11833J
Journal ID: ISSN 0022-3727; 649379; TRN: US1700998
Grant/Contract Number:
AC04-94AL85000; AC05-06OR23100; SC0001939
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physics. D, Applied Physics
Additional Journal Information:
Journal Volume: 50; Journal Issue: 6; Journal ID: ISSN 0022-3727
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; radiation transport; photons; monte carlo; particle in cell

Citation Formats

Fierro, Andrew S., Moore, Christopher Hudson, Scheiner, Brett, Yee, Benjamin T., and Hopkins, Matthew M.. Radiation transport in kinetic simulations and the influence of photoemission on electron current in self-sustaining discharges. United States: N. p., 2017. Web. doi:10.1088/1361-6463/aa506c.
Fierro, Andrew S., Moore, Christopher Hudson, Scheiner, Brett, Yee, Benjamin T., & Hopkins, Matthew M.. Radiation transport in kinetic simulations and the influence of photoemission on electron current in self-sustaining discharges. United States. doi:10.1088/1361-6463/aa506c.
Fierro, Andrew S., Moore, Christopher Hudson, Scheiner, Brett, Yee, Benjamin T., and Hopkins, Matthew M.. Thu . "Radiation transport in kinetic simulations and the influence of photoemission on electron current in self-sustaining discharges". United States. doi:10.1088/1361-6463/aa506c. https://www.osti.gov/servlets/purl/1340276.
@article{osti_1340276,
title = {Radiation transport in kinetic simulations and the influence of photoemission on electron current in self-sustaining discharges},
author = {Fierro, Andrew S. and Moore, Christopher Hudson and Scheiner, Brett and Yee, Benjamin T. and Hopkins, Matthew M.},
abstractNote = {A kinetic description for electronic excitation of helium for principal quantum number n $\leqslant $ 4 has been included into a particle-in-cell (PIC) simulation utilizing direct simulation Monte Carlo (DSMC) for electron-neutral interactions. The excited electronic levels radiate state-dependent photons with wavelengths from the extreme ultraviolet (EUV) to visible regimes. Photon wavelengths are chosen according to a Voigt distribution accounting for the natural, pressure, and Doppler broadened linewidths. This method allows for reconstruction of the emission spectrum for a non-thermalized electron energy distribution function (EEDF) and investigation of high energy photon effects on surfaces, specifically photoemission. A parallel plate discharge with a fixed field (i.e. space charge neglected) is used to investigate the effects of including photoemission for a Townsend discharge. When operating at a voltage near the self-sustaining discharge threshold, it is observed that the electron current into the anode is higher when including photoemission from the cathode than without even when accounting for self-absorption from ground state atoms. As a result, the photocurrent has been observed to account for as much as 20% of the total current from the cathode under steady-state conditions.},
doi = {10.1088/1361-6463/aa506c},
journal = {Journal of Physics. D, Applied Physics},
number = 6,
volume = 50,
place = {United States},
year = {Thu Jan 12 00:00:00 EST 2017},
month = {Thu Jan 12 00:00:00 EST 2017}
}

Journal Article:
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