Advanced Cryogenic System Capabilities for Precision Shock Physics Measurements on Z

We have developed a general purpose cryogenic target system for precision EOS studies with the Sandia Z accelerator short‐circuit current drive. Condensation of large‐area cryogenic liquid samples is accomplished using a cryostat evaporation refrigerator, shielded for survivability in the Z blast environment and connected by a thermal link to an expendable sample holder with active temperature control. Accurate shock physics measurements are performed using multiple, thermally isolated, fiber‐optic‐coupled VISAR interferometry, active shock breakout, and time‐resolved optical spectroscopy diagnostics. We describe variations of this cryogenic system currently under development for three EOS measurement applications: (1) liquid D2 shock Hugoniot experiments using magnetically driven flyer plates; (2) liquid N2 isentropic compression experiments; and (3) EOS measurements on liquid 4He at 1.5 K.