Realization of quasi-spherical implosion using pre-shaped prolate wire arrays with a compression foam target inside

Abstract

Quasi-spherical (QS) implosion of wire arrays and its impact on the foam target have been studied on the 100 ns 1.5 MA Qiangguang-I facility, which suggests that a high quality impact between the QS implosion and foam target can be achieved by adjusting load's initial shape carefully to match the external magnetic pressure. Implosions of loads with H/d ∼ 1.2 were studied with a self-emission x-ray pinhole image system and a dark field schlieren system. The radially developed spike-like instabilities indicate the spherical convergence of plasma. The observed radiation on the foam target surface suggests satisfying implosion symmetry and wire-foam impact simultaneity. An average implosion speed of 10.5 × 106 cm/s was obtained with an optical streak image system. The derived peak kinetic energy density ∼2.1 kJ/cm is remarkably higher than cylindrical cases, which agree with the expectations.

Investigation of asymmetry of wire-array Z pinches at stagnation using a 4-channel laser diagnostic

“…Different types of wire arrays have been used in Z pinches experiments including different kinds of cylindrical wire arrays [23,24], conical arrays [25], planar arrays [11], star wire arrays [18], and wire arrays for the spherical implosion [26]. Implosions in these wire arrays occur in different ways and produce Z pinches with different configurations of trailing plasma and pinch.…”

Theoretical and numerical research of wire array Z-pinch and dynamic hohlraum at IAPCM

“…Agree with our expectation, experimental results with prolate ellipsoidal foam targets show more uniform compression, and the calculated implosion velocity and its impact on the foam target agree well with the measurement. More experimental results and detail analysis can be found in [95]. …”