Plasma production by irradiating freely falling deuterium pellets with a high-power laser

Abstract

A high-power Nd : glass laser beam was focused on freely falling deuterium ice pellets. It was demonstrated that this method allows reliable and reproducible production of an isolated deuterium plasma cloud suitable for filling a plasma machine. The plasma with a total ion number of (1–2) ×1017 expands quite uniformly at a velocity of (1–3) ×107 cm/s. However, the pellet is not completely ionized, which is in accordance with theoretical predictions. The greater portion of the pellet disintegrates after the laser shot and expands with a velocity of approximately 1×106 cm/s.