Laser compression of matter: optical power and energy requirements

Abstract

The optical power PL required to achieve a given measure of inertial confinement ρR of a laser-compressed DT pellet is found to be approximately proportional to (ρR)2. This result is based on a model of self-regulating pellet ablation by hot electrons of the pellet corona that is relatively insensitive to the details of the pellet ablation process. To achieve values of ρR believed necessary in the application of laser fusion to commercial power production, 3 × 1015 W of optical power is found to be required, implying a total laser output aperture of 30 m2. (The same power requirement would appear to apply to pellet compression by charged-particle beams.) An estimate of the required laser-pulse energy WL, assuming corona-core decoupling to be the controlling limitation, is also given. In the application to commercial power production the required pulse energy is found to range from 70 kJ at 0.265 μm to 3 MJ at 10.6 μm.