Soft x-ray shock loading and momentum coupling in meteorite and planetary materials.

Lawrence, R. Jeffery ; Remo, John L. (Harvard University, Cambridge, MA) ; Furnish, Michael David

关键词: IRON METEORITES;    STONE METEORITES;    OLIVINE;    SILICON;    ALUMINIUM;    IRON;    IRRADIATION;    SOFT X RADIATION;    IMPEDANCE;    SHOCK WAVES;    MATERIALS TESTING;   

DOI  :  10.2172/1005079
RP-ID  :  SAND2010-8703
PID  :  OSTI ID: 1005079
Others  :  TRN: US1101243

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

X-ray momentum coupling coefficients, C{sub M}, were determined by measuring stress waveforms in planetary materials subjected to impulsive radiation loading from the Sandia National Laboratories Z-machine. Results from the velocity interferometry (VISAR) diagnostic provided limited equation-of-state data as well. Targets were iron and stone meteorites, magnesium rich olivine (dunite) solid and powder ({approx}5--300 {mu}m), and Si, Al, and Fe calibration targets. All samples were {approx}1 mm thick and, except for Si, backed by LiF single-crystal windows. The x-ray spectrum included a combination of thermal radiation (blackbody 170--237 eV) and line emissions from the pinch material (Cu, Ni, Al, or stainless steel). Target fluences 0.4--1.7 kJ/cm{sup 2} at intensities 43--260 GW/cm{sup 2} produced front surface plasma pressures 2.6--12.4 GPa. Stress waves driven into the samples were attenuating due to the short ({approx}5 ns) duration of the drive pulse. Attenuating wave impulse is constant allowing accurate C{sub M} measurements provided mechanical impedance mismatch between samples and the window are known. Impedance-corrected C{sub M} determined from rear-surface motion was 1.9--3.1 x 10{sup -5} s/m for stony meteorites, 2.7 and 0.5 x 10{sup -5} s/m for solid and powdered dunite, 0.8--1.4 x 10{sup -5}.