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

doi:10.1002/2016JD024970

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 »« less

Authors:

Pusateri, Elise N. ^[1]; Morris, Heidi E. ^[2]; Nelson, Eric ^[2];

^[3]

Rensselaer Polytechnic Inst., Troy, NY (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Rensselaer Polytechnic Inst., Troy, NY (United States)

Publication Date:: 2016-10-17

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.

Copy to clipboard


                    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.

Copy to clipboard


                    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.

Copy to clipboard


                    
@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}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

DOI: 10.1002/2016JD024970

Other availability

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

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

Karzas, W. J.; Latter, Richard
Physical Review, Vol. 137, Issue 5B
DOI: 10.1103/PhysRev.137.B1369

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

Similar records in OSTI.GOV collections:

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

Journal Article Pusateri, Elise N. ; Morris, Heidi E. ; Nelson, Eric M. ; ... - Journal of Geophysical Research: Atmospheres

Electromagnetic pulse (EMP) events produce low-energy conduction electrons from Compton electron or photoelectron ionizations with air. It is important to understand how conduction electrons interact with air in order to accurately predict EMP evolution and propagation. An electron swarm model can be used to monitor the time evolution of conduction electrons in an environment characterized by electric field and pressure. Here a swarm model is developed that is based on the coupled ordinary differential equations (ODEs) described by Higgins et al. (1973), hereinafter HLO. The ODEs characterize the swarm electric field, electron temperature, electron number density, and drift velocity. Importantmore »« less
Cited by 2
DOI: 10.1002/2015JD023100

Full Text Available
The development of the time dependence of the nuclear EMP electric field

Technical Report Eng, C

The nuclear electromagnetic pulse (EMP) electric field calculated with the legacy code CHAP is compared with the field given by an integral solution of Maxwell's equations, also known as the Jefimenko equation, to aid our current understanding on the factors that affect the time dependence of the EMP. For a fair comparison the CHAP current density is used as a source in the Jefimenko equation. At first, the comparison is simplified by neglecting the conduction current and replacing the standard atmosphere with a constant density air slab. The simplicity of the resultant current density aids in determining the factors thatmore »« less
DOI: 10.2172/970161

Full Text Available
3-D simulation codes for EMP E1 formation and propagation

Journal Article Friedman, A. ; Cohen, B. I. ; Eng, C. D. ; ... - Journal of Radiation Effects, Research & Engineering, vol. 36, no. 1, April 1, 2018, pp. 94-105

LLNL is developing a suite of modern tools for simulating the generation and propagation of the prompt (E1) electromagnetic pulse (EMP). These include the 3-D EMPulse code, based on particle-in-cell methods and a Cartesian grid in the laboratory frame, and a fast-running companion 3-D code, SHEMP, which employs a vector spherical harmonic decomposition. EMPulse is a comprehensive, first-principles code with full generality and requiring significant computing resources. It tracks Compton electrons directly in the laboratory frame, and includes Ohmic and swarm models for the evolving local conductivity. SHEMP builds on the methods used in Longmire's fast-running CHAP code and inmore »« less
Full Text Available
Development of a new high altitude electromagnetic pulse (HEMP) environment and resulting over head line responses

Conference Tesche, F.M. ; Barnes, P.R.

Being able to accurately determine the response of an electrical system which is excited by a high altitude nuclear electromagnetic pulse (EMP) requires a knowledge of the time history of the incident EMP field strength, as well as its angle of incidence and polarization. A commonly used, unclassified, description of this environment is provided by the ''Bell Laboratory waveform.'' Recent studies have shown, however, that this EMP waveform tends to overestimate the response of an above-ground transmission line by more than an order of magnitude. As a result, other unclassified high altitude EMP environments have been developed. This presentation discussesmore »« less
Theoretical Model for the EM Effects Induced by High-Energy Photons (Gamma, X-ray) in Dielectric Materials and Electronic Systems

Technical Report Yee, J H ; Mayhall, D J ; Bland, M F

During last twenty years, a number of models have been used to calculate the change of conductivity and dielectric strength in materials caused by the passage of high-energy photons, such as Gamma-rays and X-rays. In these models, the electromagnetic fields generated in the electronic system created by the high-energy photons have not been investigated. That is, the solution of Maxwell's equations has not been obtained for these kinds of problems. We constructed a theoretical model, described by a set of equations to solve such a problem. The model includes the equations that describe the physics of the recombination and generationmore »« less
DOI: 10.2172/15004648

Full Text Available

Similar Records

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

Abstract

Citation Formats

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

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

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

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

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

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

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

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

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

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