Compression mechanisms in the plasma focus pinch

S. Lee, S. H. Saw, Jalil Ali

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The compression of the plasma focus pinch is a dynamic process, governed by the electrodynamics of pinch elongation and opposed by the negative rate of change of current dI/dt associated with the current dip. The compressibility of the plasma is influenced by the thermodynamics primarily the specific heat ratio; with greater compressibility as the specific heat ratio γ reduces with increasing degree of freedom f of the plasma ensemble due to ionization energy for the higher Z (atomic number) gases. The most drastic compression occurs when the emitted radiation of a high-Z plasma dominates the dynamics leading in extreme cases to radiative collapse which is terminated only when the compressed density is sufficiently high for the inevitable self-absorption of radiation to occur. We discuss the central pinch equation which contains the basic electrodynamic terms with built-in thermodynamic factors and a dQ/dt term; with Q made up of a Joule heat component and absorption-corrected radiative terms. Deuterium is considered as a thermodynamic reference (fully ionized perfect gas with f = 3) as well as a zero-radiation reference (bremsstrahlung only; with radiation power negligible compared with electrodynamic power). Higher Z gases are then considered and regimes of thermodynamic enhancement of compression are systematically identified as are regimes of radiation-enhancement. The code which incorporates all these effects is used to compute pinch radius ratios in various gases as a measure of compression. Systematic numerical experiments reveal increasing severity in radiation-enhancement of compressions as atomic number increases. The work progresses towards a scaling law for radiative collapse and a generalized specific heat ratio incorporating radiation.

Original languageEnglish
Title of host publicationInternational Conference on Plasma Science and Applications, ICPSA 2016
PublisherAmerican Institute of Physics Inc.
Volume1824
ISBN (Electronic)9780735414921
DOIs
StatePublished - 30 Mar 2017
Event9th International Conference on Plasma Science and Applications, ICPSA 2016 - Langkawi, Malaysia

Other

Other9th International Conference on Plasma Science and Applications, ICPSA 2016
CountryMalaysia
CityLangkawi
Period28/11/1630/11/16

Fingerprint

thermodynamics
electrodynamics
specific heat
augmentation
gases
plasma focus
compressibility
self absorption
ideal gas
ionized gases
bremsstrahlung
scaling laws
elongation
deuterium
degrees of freedom
ionization
heat
radii
energy

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Lee, S., Saw, S. H., & Ali, J. (2017). Compression mechanisms in the plasma focus pinch. In International Conference on Plasma Science and Applications, ICPSA 2016 (Vol. 1824). [4978814] American Institute of Physics Inc.. DOI: 10.1063/1.4978814

Compression mechanisms in the plasma focus pinch. / Lee, S.; Saw, S. H.; Ali, Jalil.

International Conference on Plasma Science and Applications, ICPSA 2016. Vol. 1824 American Institute of Physics Inc., 2017. 4978814.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Lee, S, Saw, SH & Ali, J 2017, Compression mechanisms in the plasma focus pinch. in International Conference on Plasma Science and Applications, ICPSA 2016. vol. 1824, 4978814, American Institute of Physics Inc., 9th International Conference on Plasma Science and Applications, ICPSA 2016, Langkawi, Malaysia, 28-30 November. DOI: 10.1063/1.4978814
Lee S, Saw SH, Ali J. Compression mechanisms in the plasma focus pinch. In International Conference on Plasma Science and Applications, ICPSA 2016. Vol. 1824. American Institute of Physics Inc.2017. 4978814. Available from, DOI: 10.1063/1.4978814

Lee, S.; Saw, S. H.; Ali, Jalil / Compression mechanisms in the plasma focus pinch.

International Conference on Plasma Science and Applications, ICPSA 2016. Vol. 1824 American Institute of Physics Inc., 2017. 4978814.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

@inbook{902950ce43dc49f48b05342c81e1621f,
title = "Compression mechanisms in the plasma focus pinch",
abstract = "The compression of the plasma focus pinch is a dynamic process, governed by the electrodynamics of pinch elongation and opposed by the negative rate of change of current dI/dt associated with the current dip. The compressibility of the plasma is influenced by the thermodynamics primarily the specific heat ratio; with greater compressibility as the specific heat ratio γ reduces with increasing degree of freedom f of the plasma ensemble due to ionization energy for the higher Z (atomic number) gases. The most drastic compression occurs when the emitted radiation of a high-Z plasma dominates the dynamics leading in extreme cases to radiative collapse which is terminated only when the compressed density is sufficiently high for the inevitable self-absorption of radiation to occur. We discuss the central pinch equation which contains the basic electrodynamic terms with built-in thermodynamic factors and a dQ/dt term; with Q made up of a Joule heat component and absorption-corrected radiative terms. Deuterium is considered as a thermodynamic reference (fully ionized perfect gas with f = 3) as well as a zero-radiation reference (bremsstrahlung only; with radiation power negligible compared with electrodynamic power). Higher Z gases are then considered and regimes of thermodynamic enhancement of compression are systematically identified as are regimes of radiation-enhancement. The code which incorporates all these effects is used to compute pinch radius ratios in various gases as a measure of compression. Systematic numerical experiments reveal increasing severity in radiation-enhancement of compressions as atomic number increases. The work progresses towards a scaling law for radiative collapse and a generalized specific heat ratio incorporating radiation.",
author = "S. Lee and Saw, {S. H.} and Jalil Ali",
year = "2017",
month = "3",
doi = "10.1063/1.4978814",
volume = "1824",
booktitle = "International Conference on Plasma Science and Applications, ICPSA 2016",
publisher = "American Institute of Physics Inc.",

}

TY - CHAP

T1 - Compression mechanisms in the plasma focus pinch

AU - Lee,S.

AU - Saw,S. H.

AU - Ali,Jalil

PY - 2017/3/30

Y1 - 2017/3/30

N2 - The compression of the plasma focus pinch is a dynamic process, governed by the electrodynamics of pinch elongation and opposed by the negative rate of change of current dI/dt associated with the current dip. The compressibility of the plasma is influenced by the thermodynamics primarily the specific heat ratio; with greater compressibility as the specific heat ratio γ reduces with increasing degree of freedom f of the plasma ensemble due to ionization energy for the higher Z (atomic number) gases. The most drastic compression occurs when the emitted radiation of a high-Z plasma dominates the dynamics leading in extreme cases to radiative collapse which is terminated only when the compressed density is sufficiently high for the inevitable self-absorption of radiation to occur. We discuss the central pinch equation which contains the basic electrodynamic terms with built-in thermodynamic factors and a dQ/dt term; with Q made up of a Joule heat component and absorption-corrected radiative terms. Deuterium is considered as a thermodynamic reference (fully ionized perfect gas with f = 3) as well as a zero-radiation reference (bremsstrahlung only; with radiation power negligible compared with electrodynamic power). Higher Z gases are then considered and regimes of thermodynamic enhancement of compression are systematically identified as are regimes of radiation-enhancement. The code which incorporates all these effects is used to compute pinch radius ratios in various gases as a measure of compression. Systematic numerical experiments reveal increasing severity in radiation-enhancement of compressions as atomic number increases. The work progresses towards a scaling law for radiative collapse and a generalized specific heat ratio incorporating radiation.

AB - The compression of the plasma focus pinch is a dynamic process, governed by the electrodynamics of pinch elongation and opposed by the negative rate of change of current dI/dt associated with the current dip. The compressibility of the plasma is influenced by the thermodynamics primarily the specific heat ratio; with greater compressibility as the specific heat ratio γ reduces with increasing degree of freedom f of the plasma ensemble due to ionization energy for the higher Z (atomic number) gases. The most drastic compression occurs when the emitted radiation of a high-Z plasma dominates the dynamics leading in extreme cases to radiative collapse which is terminated only when the compressed density is sufficiently high for the inevitable self-absorption of radiation to occur. We discuss the central pinch equation which contains the basic electrodynamic terms with built-in thermodynamic factors and a dQ/dt term; with Q made up of a Joule heat component and absorption-corrected radiative terms. Deuterium is considered as a thermodynamic reference (fully ionized perfect gas with f = 3) as well as a zero-radiation reference (bremsstrahlung only; with radiation power negligible compared with electrodynamic power). Higher Z gases are then considered and regimes of thermodynamic enhancement of compression are systematically identified as are regimes of radiation-enhancement. The code which incorporates all these effects is used to compute pinch radius ratios in various gases as a measure of compression. Systematic numerical experiments reveal increasing severity in radiation-enhancement of compressions as atomic number increases. The work progresses towards a scaling law for radiative collapse and a generalized specific heat ratio incorporating radiation.

UR - http://www.scopus.com/inward/record.url?scp=85018520364&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85018520364&partnerID=8YFLogxK

U2 - 10.1063/1.4978814

DO - 10.1063/1.4978814

M3 - Conference contribution

VL - 1824

BT - International Conference on Plasma Science and Applications, ICPSA 2016

PB - American Institute of Physics Inc.

ER -