Dynamics of the spectral behaviour of an ultrashort laser pulse in an argon-gas-filled capillary discharge-preformed plasma channel

S Sakai,N Yugami,R Kodama,Y Sentoku,T Higashiguchi,N Bobrova,P Mora,K A Tanaka,E Moses

doi:10.1051/epjconf/20135917002

Abstract

We have reported the argon plasma waveguide produced in an alumina (Al2 O3 ) capillary discharge and used to guide ultrashort laser pulses at intensities of the order of 1016 W/cm2 . A one-dimensional magnetohydrodynamic (MHD) code was used to evaluate the average degree of ionization of Ar in the preformed plasma channel. The spectrum of the propagated laser pulse in the Ar plasma waveguide was not modified and was well reproduced by a particle-in-cell (PIC) simulation under initial ion charge state of Ar3+ in the preformed plasma waveguide. The optimum timing for the laser pulse injection was around 150 ns after initiation of a discharge with a peak current of 200 A.

Highlights

Ultrashort-pulse high-intensity lasers are used for high-field plasma physics under extreme conditions, but can yield temporally resolved ultrafast phenomena from a plasma
We have reported the argon plasma waveguide produced in an alumina (Al2O3) capillary discharge and used to guide ultrashort laser pulses at intensities of the order of 1016 W/cm2
We report the behaviour of an argon plasma waveguide produced in the capillary discharge and its use to guide ultrashort laser pulses at laser intensities of the order of 1016 W/cm2

Summary

INTRODUCTION

Ultrashort-pulse high-intensity lasers are used for high-field plasma physics under extreme conditions, but can yield temporally resolved ultrafast phenomena from a plasma. In the case of gas-filled capillary soft x-ray lasers, higher charge state ions (Ar8+−Ar10+) should be produced in order to obtain coherent XUV radiation. We report the behaviour of an argon plasma waveguide produced in the capillary discharge and its use to guide ultrashort laser pulses at laser intensities of the order of 1016 W/cm. In our experiment the spectrum of the propagated laser pulse in the argon plasma waveguide was not modified, and it was well reproduced by a particle-in-cell (PIC) simulations

Experimental setup

Argon preformed plasma channel in a capillary

Laser spectral behaviour

SUMMARY