Development of a high-power capillary discharge for studying ablation at the micron scale

Abstract

Summary form only given. The objective of this work is to develop a capillary discharge for studying (at a very fundamental level) the processes by which materials ablate when exposed to cold (1-3 eV) thermal plasmas. A key requirement is a high degree of control over the composition, power, and energy of the plasma so that small but measureable amounts of damage can be produced and in turn compared to ablation rates predicted by first-principles computation using molecular dynamics (MD) simulations. This paper describes the design and performance of a non-consumable capillary discharge that uses a quartz liner, to produce a 1 eV argon plasma. The argon feed-gas contains 2% hydrogen for permitting additional spectroscopic diagnostics of the plasma. Measurements of plasma temperature, plasma density, and power are provided for various configurations of the power supply and capillary which was operated at 4 kV, and which used a flash lamp type circuit for initiating the discharge.