Investigation of ablation of thin foil aluminum ribbon array at 1.5 MA

Abstract

We present experimental studies of initiation and ablation of a thin foil aluminum ribbon array at the 1.5 MA current level. In contrast to the previous work, we employ ribbon arrays with different ribbon gap parameters to investigate how this affects plasma initiation and foil ablation. Gated narrowband ultraviolet imaging indicated that the current was disorderly distributed at early period of discharge. But later on, it became axially stable and azimuthally symmetrical even for load with a gap as small as 0.1 mm. Using magnetic field probes installed inside and outside the array, we also observed that precursor current at positions with a distance of less than 2.7 mm to the central axis for 4-mm-radius arrays decreased when ribbon gap became small. Results of 0.2 mm gap ribbon array showed an evidence that ribbons can be merged. These observations imply that thin foil ribbon arrays may have potential applications in z-pinch experiments on large scale pulsed power facilities.

Simulations on the multi-shell target ignition driven by radiation pulse in Z-pinch dynamic hohlraum*

“…The initiation of the Z-pinch liner can be a complicated process. If the liner is made of an extremely thin metal shell or a narrow-gap ribbon array, the precursor plasma may be restrained effectively, [30] which leads the liner to be imploded in shell model. If the liner is made of wire array, the liner may implode in a snow-plow way.…”

Numerical simulation on a new cylindrical target for Z-pinch driven inertial confinement fusion

“…Besides, the precursor plasma of wire-array Z-pinch will preheat the target, and this may result in mismatch between the pinch plasma and the preheated target. The solid density outer layer may be from an extremely thin metal shell or a narrow-gap ribbon array, so the precursor plasma can be restrained effectively [22], and the shell density may also reach a high level. The Rayleigh-Taylor instability, which is a challenge to the implosion symmetry, can be partly alleviated by finely fabrication of the initial shell or ribbon array.…”