skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Comparison of equilibrium ohmic and nonequilibrium swarm models for monitoring conduction electron evolution in high-altitude EMP calculations

Abstract

Here, atmospheric electromagnetic pulse (EMP) events are important physical phenomena that occur through both man-made and natural processes. Radiation-induced currents and voltages in EMP can couple with electrical systems, such as those found in satellites, and cause significant damage. Due to the disruptive nature of EMP, it is important to accurately predict EMP evolution and propagation with computational models. CHAP-LA (Compton High Altitude Pulse-Los Alamos) is a state-of-the-art EMP code that solves Maxwell inline images equations for gamma source-induced electromagnetic fields in the atmosphere. In EMP, low-energy, conduction electrons constitute a conduction current that limits the EMP by opposing the Compton current. CHAP-LA calculates the conduction current using an equilibrium ohmic model. The equilibrium model works well at low altitudes, where the electron energy equilibration time is short compared to the rise time or duration of the EMP. At high altitudes, the equilibration time increases beyond the EMP rise time and the predicted equilibrium ionization rate becomes very large. The ohmic model predicts an unphysically large production of conduction electrons which prematurely and abruptly shorts the EMP in the simulation code. An electron swarm model, which implicitly accounts for the time evolution of the conduction electron energy distribution, can bemore » used to overcome the limitations exhibited by the equilibrium ohmic model. We have developed and validated an electron swarm model previously in Pusateri et al. (2015). Here we demonstrate EMP damping behavior caused by the ohmic model at high altitudes and show improvements on high-altitude, upward EMP modeling obtained by integrating a swarm model into CHAP-LA.« less

Authors:
 [1];  [2];  [2]; ORCiD logo [3]
  1. Rensselaer Polytechnic Inst., Troy, NY (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Rensselaer Polytechnic Inst., Troy, NY (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1329596
Alternate Identifier(s):
OSTI ID: 1402162
Report Number(s):
LA-UR-16-20896
Journal ID: ISSN 2169-897X
Grant/Contract Number:  
AC52-06NA25396
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research: Atmospheres
Additional Journal Information:
Journal Name: Journal of Geophysical Research: Atmospheres; Journal ID: ISSN 2169-897X
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; EMP, Electron Swarm

Citation Formats

Pusateri, Elise N., Morris, Heidi E., Nelson, Eric, and Ji, Wei. Comparison of equilibrium ohmic and nonequilibrium swarm models for monitoring conduction electron evolution in high-altitude EMP calculations. United States: N. p., 2016. Web. doi:10.1002/2016JD024970.
Pusateri, Elise N., Morris, Heidi E., Nelson, Eric, & Ji, Wei. Comparison of equilibrium ohmic and nonequilibrium swarm models for monitoring conduction electron evolution in high-altitude EMP calculations. United States. doi:10.1002/2016JD024970.
Pusateri, Elise N., Morris, Heidi E., Nelson, Eric, and Ji, Wei. Mon . "Comparison of equilibrium ohmic and nonequilibrium swarm models for monitoring conduction electron evolution in high-altitude EMP calculations". United States. doi:10.1002/2016JD024970. https://www.osti.gov/servlets/purl/1329596.
@article{osti_1329596,
title = {Comparison of equilibrium ohmic and nonequilibrium swarm models for monitoring conduction electron evolution in high-altitude EMP calculations},
author = {Pusateri, Elise N. and Morris, Heidi E. and Nelson, Eric and Ji, Wei},
abstractNote = {Here, atmospheric electromagnetic pulse (EMP) events are important physical phenomena that occur through both man-made and natural processes. Radiation-induced currents and voltages in EMP can couple with electrical systems, such as those found in satellites, and cause significant damage. Due to the disruptive nature of EMP, it is important to accurately predict EMP evolution and propagation with computational models. CHAP-LA (Compton High Altitude Pulse-Los Alamos) is a state-of-the-art EMP code that solves Maxwell inline images equations for gamma source-induced electromagnetic fields in the atmosphere. In EMP, low-energy, conduction electrons constitute a conduction current that limits the EMP by opposing the Compton current. CHAP-LA calculates the conduction current using an equilibrium ohmic model. The equilibrium model works well at low altitudes, where the electron energy equilibration time is short compared to the rise time or duration of the EMP. At high altitudes, the equilibration time increases beyond the EMP rise time and the predicted equilibrium ionization rate becomes very large. The ohmic model predicts an unphysically large production of conduction electrons which prematurely and abruptly shorts the EMP in the simulation code. An electron swarm model, which implicitly accounts for the time evolution of the conduction electron energy distribution, can be used to overcome the limitations exhibited by the equilibrium ohmic model. We have developed and validated an electron swarm model previously in Pusateri et al. (2015). Here we demonstrate EMP damping behavior caused by the ohmic model at high altitudes and show improvements on high-altitude, upward EMP modeling obtained by integrating a swarm model into CHAP-LA.},
doi = {10.1002/2016JD024970},
journal = {Journal of Geophysical Research: Atmospheres},
number = ,
volume = ,
place = {United States},
year = {2016},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Determination of equilibrium electron temperature and times using an electron swarm model with BOLSIG+ calculated collision frequencies and rate coefficients
journal, August 2015

  • Pusateri, Elise N.; Morris, Heidi E.; Nelson, Eric M.
  • Journal of Geophysical Research: Atmospheres, Vol. 120, Issue 15
  • DOI: 10.1002/2015JD023100

Femtosecond ultraviolet laser pulse induced lightning discharges in gases
journal, March 1995

  • Xin Miao Zhao, ; Diels, J. -C.
  • IEEE Journal of Quantum Electronics, Vol. 31, Issue 3
  • DOI: 10.1109/3.364418

Detection of the Electromagnetic Radiation from Nuclear Explosions in Space
journal, March 1965


On the Electromagnetic Pulse Produced by Nuclear Explosions
journal, February 1978

  • Longmire, Conrad
  • IEEE Transactions on Electromagnetic Compatibility, Vol. EMC-20, Issue 1
  • DOI: 10.1109/TEMC.1978.303688

Prompt Nuclear EMP and Synchrotron Radiation: A Resolution of Two Approaches
journal, August 2005

  • Roussel-Dupre, R. A.
  • IEEE Transactions on Electromagnetic Compatibility, Vol. 47, Issue 3
  • DOI: 10.1109/TEMC.2005.851724