Quantifying Preheat in High-Pressure Equation of State Experiments with an Interferometric Laser Probe
Abstract
We present results of an experimental campaign at the Nova Laser Facility using an active interferometric laser probe beam to precisely quantify preheat and shock velocities. High-intensity lasers can achieve high-pressure (> 10Mbar) conditions, but preheat from x-rays and hot electrons displaces the principle Hugoniot locus complicating EOS measurements. Sensitive discrimination between various theoretical models demands EOS Hugoniot experiments with a precision ~1% in measured preheat and shock velocities. Our interferometric probe is sensitive to target expansion ~40nm which corresponds to a material-dependent preheat temperature of < 500^circC. The shock breakout region is imaged onto a streak camera slit with an f/4, 20X imaging system allowing streak camera limited spatial resolution of the shock breakout region for impedance-matching EOS experiments between a standard material with well-known EOS and other materials.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 1997
- Bibcode:
- 1997APS..DPPpTO202G