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Title: Modeling of a square pulsed capillary discharge waveguide for interferometry measurements

Abstract

Slow pulsed capillary discharges in round capillaries are currently under investigation for use as plasma channel laser waveguides in laser-wakefield acceleration, x-ray lasers, and higher-harmonic generation. In this study, a capillary discharge with a square cross section is presented. The electron density, which determines the laser guiding properties, can be measured by means of transverse interferometry in this device. Using a numerical model of the plasma and the capillary wall, an analysis of the discharge is made. The results predict that the square channel is capable of guiding circular laser pulses. The guiding properties are quite similar to those of a round channel with nearly the same diameter as the channel width. This suggests the results obtained by measuring the square capillary discharge are applicable for round channels as well. It was found that the wall heating was inhomogeneous, which makes the wall more susceptible to ablation. The heating of the wall changes the transverse optical pathlength in the interferometry experiments.

Authors:
; ; ; ; ;  [1];  [2]
  1. Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MD Eindhoven (Netherlands)
  2. (United Kingdom)
Publication Date:
OSTI Identifier:
20974848
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 2; Other Information: DOI: 10.1063/1.2432053; (c) 2007 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; ABLATION; ACCELERATION; ELECTRIC DISCHARGES; ELECTRON DENSITY; HARMONIC GENERATION; HEATING; INTERFEROMETRY; PLASMA; SIMULATION; WAVEGUIDES; X-RAY LASERS

Citation Formats

Broks, B. H. P., Dijk, W. van, Mullen, J. J. A. W. van der, Gonsalves, A. J., Rowlands-Rees, T. P., Hooker, S. M., and Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU. Modeling of a square pulsed capillary discharge waveguide for interferometry measurements. United States: N. p., 2007. Web. doi:10.1063/1.2432053.
Broks, B. H. P., Dijk, W. van, Mullen, J. J. A. W. van der, Gonsalves, A. J., Rowlands-Rees, T. P., Hooker, S. M., & Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU. Modeling of a square pulsed capillary discharge waveguide for interferometry measurements. United States. doi:10.1063/1.2432053.
Broks, B. H. P., Dijk, W. van, Mullen, J. J. A. W. van der, Gonsalves, A. J., Rowlands-Rees, T. P., Hooker, S. M., and Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU. Thu . "Modeling of a square pulsed capillary discharge waveguide for interferometry measurements". United States. doi:10.1063/1.2432053.
@article{osti_20974848,
title = {Modeling of a square pulsed capillary discharge waveguide for interferometry measurements},
author = {Broks, B. H. P. and Dijk, W. van and Mullen, J. J. A. W. van der and Gonsalves, A. J. and Rowlands-Rees, T. P. and Hooker, S. M. and Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU},
abstractNote = {Slow pulsed capillary discharges in round capillaries are currently under investigation for use as plasma channel laser waveguides in laser-wakefield acceleration, x-ray lasers, and higher-harmonic generation. In this study, a capillary discharge with a square cross section is presented. The electron density, which determines the laser guiding properties, can be measured by means of transverse interferometry in this device. Using a numerical model of the plasma and the capillary wall, an analysis of the discharge is made. The results predict that the square channel is capable of guiding circular laser pulses. The guiding properties are quite similar to those of a round channel with nearly the same diameter as the channel width. This suggests the results obtained by measuring the square capillary discharge are applicable for round channels as well. It was found that the wall heating was inhomogeneous, which makes the wall more susceptible to ablation. The heating of the wall changes the transverse optical pathlength in the interferometry experiments.},
doi = {10.1063/1.2432053},
journal = {Physics of Plasmas},
number = 2,
volume = 14,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
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  • Slow pulsed capillary discharges are under investigation for use as plasma channel waveguides in laser-wakefield acceleration. In this study, we present a non-local thermal equilibrium (non-LTE) plasma model with a model for the wall temperature coupled to it. This model is used to describe an example of a slow pulsed capillary discharge, and the results are compared with experimental results. The agreement is satisfactory, indicating suitability of our model. Significant deviations from LTE are found during the formation of the plasma channel. The model is also used to study the influence of the discharge current on the guiding properties. Itmore » was found that this influence is small over most of the current range that was investigated.« less
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