Possibility of rapidly cooling a multiply charged laser plasma and using it as an active medium for generating short-wavelength radiation

In order to increase the rate of cooling of a laser-produced plasma, formed by the breakdown of a gas in a focused light beam, it is proposed to surround it with a plasma shell of substantially lower temperature, produced by means of an additional picosecond pulse. Electron heat conduction in the colder outer region causes the temperature at the center of the plasma to drop. The recombination flux in the central region can thereby be increased considerably at the expense of a relatively small reduction in the plasma density. Estimates show that under such conditions one can expect an appreciable inversion of short-wavelength transitions and lasing in the far vacuum ultraviolet.