A theory is proposed for the process of irradiation of finite solid targets of light atoms (H2, D2, Li) by giant laser pulses. The properties of the plasma produced are studied and the conditions to be satisfied in order to obtain an isotropic plasma are given.

Some properties of the plasmas produced by irradiating light solids by laser pulses

Plasma production by laser

The output beam of a Ruby Giant Pulse Laser (30 nsec halfwidth, up to 100 MW peak power) was focussed onto the surface of aluminium and copper-targets, which were cleaned by heating them to 500 degrees C at 10-7 torr. The evaporated ions and electrons were detected at a distance of 170cm away from the target, after having passed some retarding grids. By a combination of time of flight- and retarding potential measurements the different charged ions could be separated and their energy distribution and intensity ratios were measured. his yields information simultaneously about the kinetic ion energies and the plasma electron temperature. It turns out, that the mean kinetic energy of the ions is proportional to their charge and about 100 times larger than their thermal energy. The experimental results and their interpretation in connection with the mechanisms of plasma generation and heating by laser light are discussed and compared with theoretical and experimental investigations of other authors.

https://iopscience.iop.org/article/10.1088/0032-1028/12/9/004/pdf

Investigation of laser-produced plasmas from metal-surfaces

This paper provides a review of papers published on laser interaction with solids, from the point of view of plasma production. The material is divided into one section dealing with theoretical work and one dealing with experiments. In addition, an extensive bibliography of papers published on the subject up to the end of 1968 is presented.

Laser interaction with solids - A bibliographical review

The condition that nτ, the product of density and containment time, is sufficiently high to strip ions almost to their `steady-state' degree of ionization can be achieved in certain high-density pulsed devices of thermonuclear interest. One such plasma, that produced when a solid pellet is irradiated by a Q-spoiled laser beam, looks promising as a source of highly stripped ions. Present calculations show that the ions could be extracted for acceleration experiments with a mean charge exceeding ten.

https://iopscience.iop.org/article/10.1088/0022-3727/2/12/311/pdf

P.A.H. Saunders

Papers

Laser produced plasmas from isolated solid hydrogen pellets

Laser produced plasmas from solid hydrogen targets