Study of Hypervelocity Impact Plasma Expansion

摘要

Hypervelocity impact testing at the Max Planck Institute for Nuclear Physics was undertaken with a suite of RF, optical, and plasma sensors. Iron particles between 10~(10) g and 10~(-15) g were accelerated to speeds of 1 km/s to 50 km/s using a Van de Graaff dust accelerator and were impacted on metallic targets. The retarding potential analyzers (RPAs) designed and constructed to measure impact-generated plasma are described in detail. Several optical signals from a photomultiplier tube were detected and found to be temporally coincident with impact events that also generated measurable plasma. The plasma measurements from the RPAs indicate a dependence on target electrical bias and material. The expansion speed of plasma generated from impacts on unbiased tungsten was found to be approximately 20 km/s.