Table-top generation and spectroscopic study of ~10 TPa high-energy density materials with C_(60)~+ hypervelocity (~100 km/s) impact

摘要

The use of nanoparticles as flyers to create shock pressures exceeding 10 TPa and to investigate the matters in planetary or stellar interiors has been pursued by the author for two decades. Previous studies led by the author at Brookhaven National Lab (BNL) in 1994 proved that such ultra-strong shocks can be generated with charged bio and water nanoparticles by accelerating them with an electrostatic accelerator and impacting them on solids at ~ 100 km/s. The author in 2008 showed that the BNL nanoplasmas produced intense bursts of soft x-rays (hν ~ 100 eV) from optical decay of excimer-like Metastable Innershell Molecular State, MIMS, formed by inner-shell electron excitation. The conversion efficiency from the nanoflyer kinetic energy to the radiation energy was unexpectedly high, ~38%, which was attributed to high efficiency pressure ionization conversion of impact energy to MIMS excitation energy and MIMS collective optical decay in tens of fs via Dicke Superradiance. Now, this paper reports an experimental study performed with C_(60) as a nano-flyer that permitted reduction of the size and complexity of the apparatus by orders of magnitude compared with the BNL one. The present results confirm the BNL results unambiguously, demonstrate a pathway to scaling up of soft x-ray intensity, and open doors to a wide range of applications from lithography to inertial fusion.