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Title: Effects of an axial magnetic field on Z-pinch plasmas for extreme ultraviolet sources

Abstract

This paper describes the effect of an axial magnetic field (B{sub z}) on plasma pinch dynamics and on the extreme ultraviolet (EUV) emission property of a compact Z-pinch device for EUV sources. The Z-pinch xenon plasma was driven by a pulse current with an amplitude of 27 kA and duration of 150 ns in an alumina tube with a diameter of 5 mm. A quasistatic magnetic field of up to 360 G is applied to the plasma. The EUV emission was evaluated for spectra, spatial distribution of the emission, and light energy at 13.5 nm with 2% bandwidth. A time-resolved interferogram provides the electron line density and pinch dynamics of the plasma. When a magnetic field of 160 G was applied to the plasma, the emission energy was approximately double that without the magnetic field. The spectroscopic measurement shows that the EUV spectrum drastically varies with magnetic-field strength. The time-resolved interferogram indicates that the axial magnetic field contributes by making the plasma compression smooth and by sustaining certain plasma conditions longer. From these experimental results, it was concluded that applying an axial magnetic field can be an effective method to improve EUV emission.

Authors:
; ; ; ; ; ;  [1]
  1. Department of Electrical and Computer Engineering, Kumamoto University, 39-1, Kurokami 2-Chome, Kumamoto 860-8555 (Japan)
Publication Date:
OSTI Identifier:
20787779
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 99; Journal Issue: 1; Other Information: DOI: 10.1063/1.2158132; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALUMINIUM OXIDES; ELECTRON DENSITY; EXTREME ULTRAVIOLET RADIATION; LINEAR Z PINCH DEVICES; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; PHOTON EMISSION; PLASMA; PLASMA DENSITY; PLASMA DIAGNOSTICS; PULSES; SPATIAL DISTRIBUTION; TIME RESOLUTION; XENON

Citation Formats

Katsuki, Sunao, Kimura, Akihiro, Kondo, Yoshihiro, Horita, Hiroyuki, Namihira, Takao, Sakugawa, Takashi, and Akiyama, Hidenori. Effects of an axial magnetic field on Z-pinch plasmas for extreme ultraviolet sources. United States: N. p., 2006. Web. doi:10.1063/1.2158132.
Katsuki, Sunao, Kimura, Akihiro, Kondo, Yoshihiro, Horita, Hiroyuki, Namihira, Takao, Sakugawa, Takashi, & Akiyama, Hidenori. Effects of an axial magnetic field on Z-pinch plasmas for extreme ultraviolet sources. United States. doi:10.1063/1.2158132.
Katsuki, Sunao, Kimura, Akihiro, Kondo, Yoshihiro, Horita, Hiroyuki, Namihira, Takao, Sakugawa, Takashi, and Akiyama, Hidenori. Sun . "Effects of an axial magnetic field on Z-pinch plasmas for extreme ultraviolet sources". United States. doi:10.1063/1.2158132.
@article{osti_20787779,
title = {Effects of an axial magnetic field on Z-pinch plasmas for extreme ultraviolet sources},
author = {Katsuki, Sunao and Kimura, Akihiro and Kondo, Yoshihiro and Horita, Hiroyuki and Namihira, Takao and Sakugawa, Takashi and Akiyama, Hidenori},
abstractNote = {This paper describes the effect of an axial magnetic field (B{sub z}) on plasma pinch dynamics and on the extreme ultraviolet (EUV) emission property of a compact Z-pinch device for EUV sources. The Z-pinch xenon plasma was driven by a pulse current with an amplitude of 27 kA and duration of 150 ns in an alumina tube with a diameter of 5 mm. A quasistatic magnetic field of up to 360 G is applied to the plasma. The EUV emission was evaluated for spectra, spatial distribution of the emission, and light energy at 13.5 nm with 2% bandwidth. A time-resolved interferogram provides the electron line density and pinch dynamics of the plasma. When a magnetic field of 160 G was applied to the plasma, the emission energy was approximately double that without the magnetic field. The spectroscopic measurement shows that the EUV spectrum drastically varies with magnetic-field strength. The time-resolved interferogram indicates that the axial magnetic field contributes by making the plasma compression smooth and by sustaining certain plasma conditions longer. From these experimental results, it was concluded that applying an axial magnetic field can be an effective method to improve EUV emission.},
doi = {10.1063/1.2158132},
journal = {Journal of Applied Physics},
number = 1,
volume = 99,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • A low-current and low-compression z-pinch nitrogen plasma is heated up by means of a short laser pulse. Spectra are taken in the extreme ultraviolet spectral range from 11 to 18 nm to estimate the heating effect. Without additional laser heating the initial plasma conditions are n{sub e}{approx_equal}10{sup 17} cm{sup -3} and T{sub e}{approx_equal}11 eV. The additional laser heating causes an increase in the electron temperature of about a factor of 5 to T{sub e}{approx_equal}57 eV, whereas the electron density nearly remains at the initial value. The experimentally determined values are compared to the results obtained by means of simulations andmore » are in fairly good agreement.« less
  • The development and use of a single-fluid two-temperature approximated 2-D Magneto-Hydrodynamics code is reported. Z-pinch dynamics and the evolution of Magneto-Rayleigh-Taylor (MRT) instabilities in a gas jet type Extreme Ultraviolet (EUV) source are investigated with this code. The implosion and stagnation processes of the Z-pinch dynamics and the influence of initial perturbations (single mode, multi- mode, and random seeds) on MRT instability are discussed in detail. In the case of single mode seeds, the simulation shows that the growth rates for mm-scale wavelengths up to 4 mm are between 0.05 and 0.065 ns{sup −1}. For multi-mode seeds, the mode couplingmore » effect leads to a series of other harmonics, and complicates MRT instability evolution. For perturbation by random seeds, the modes evolve to longer wavelengths and finally converge to a mm-scale wavelength approximately 1 mm. MRT instabilities can also alter the pinch stagnation state and lead to temperature and density fluctuations along the Z axis, which eventually affects the homogeneity of the EUV radiation output. Finally, the simulation results are related to experimental results to discuss the mitigations of MRT instability.« less
  • Cited by 1
  • The effect of an externally-applied 70-100 kG axial magnetic field in the temporal evolution of the extreme ultraviolet emission from a 500 {mu}m diameter highly-ionized LiH capillary discharge has been studied. In the absence of external magnetic confinement, strong emission from ionic transitions excited by collisional recombination is observed at the end of the current pulse. The externally-applied magnetic field is observed to reduce the intensity of the recombination lines by decreasing the rate of plasma cooling by electron heat conduction to the capillary walls. In contrast, the self-generated magnetic field of the discharge aids to the generation of anmore » initially hot plasma, and allows rapid conduction cooling at the end of the current pulse. The results are discussed in relation to a proposed capillary-discharge-exited extreme ultraviolet recombination laser scheme.« less
  • Abstract not provided.