Quasi-spherical superfast Z-pinch implosion for pellet irradiation

Experiments on the Angara-5-1 (TRINITI, Russia) [9, 13] and Z-machine (SNL, USA) [3, 8] have shown the attractiveness of liners Z-pinches as drivers for an ignition of a thermonuclear target with an indirect irradiation. In the last years developments of pulsed power generators have achieved a level close to the pellet ignition threshold Q > 10. Though the parameters of the planned facilities are close to satisfy the ignition requirements or even surpass it, the search for a more effective use of the kinetic energy of imploding liner pinch has not lost its attractiveness. The transition from a cylindrical liner to a quasi-spherical one is the most natural way to solve this problem. The quasi-spherical compression of liners with direct use of the kinetic energy for an implosion of the target shell was analyzed in a number of studies [4, 5, 10]. The enhanced instability of the quasi-spherical liner implosion is a serious of issues of a direct compression scheme [4]. Therefore, in Ref. [10] a scheme of the quasi-spherical liner with an indirect exposure of the target was proposed. This paper presents the results of recent calculations of quasi-spherical liners with a current of 40 MA, and the first model experiments with a quasi-spherical wire-array installation performed at Angara-5-1 with a current up to 3 MA.