Laser plasma interactions and thermonuclear fusion

Abstract

The physical processes involved in the absorption of laser energy and heating of a pellet plasma are reviewed. It is shown that induced parametric temporal instabilities, in which large amplitude collective plasma waves and sound waves are created by the laser beam of frequency w near the plasma frequency w_p(r), play the dominant role in heating the pellet. With presently attainable laser-beam energies, in order to satisfy the Lawson breakeven condition, and to produce thermonuclear energy, it is necessary to precompress solid deuterium tritium pellets by a factor 10³-10⁴. The gain factor for the new laser-driven impiosion and self-heating scheme in which the generated a-particles are absorbed in the pellet itself has been calculated. Theoretically, it is shown that a fusion reactor based on this scheme is feasible, but practical difficulties still remain to be tackled.