Laser heating of a dense plasma pinch

Abstract

A single fluid, two−temperature, one−dimensional magnetohydrodynamic model has been developed to describe the properties of a linear pinch plasma heated by an axially directed laser beam. The coupling of the laser light energy with the pinch dynamics is studied in detail. The laser light absorption occurs primarily through the inverse bremsstrahlung process, but the effect of enhanced absorption for sufficiently intense lasers has also been studied. Results of the calculations show a strong interaction between the heating by radial compression (pinching) and heating by the laser beam. It was found that the most important considerations in obtaining efficient heating of the plasma are the time profiles of the laser pulse and the electric current. The results of the anomalous absorption studies indicate that the increased absorption can cause the electron and ion temperatures to decouple and may actually be detrimental to the efficient laser heating of dense pinch type plasmas.