激光冲击钒和钛的扩展X射线吸收精细结构测量以及钛中的晶体相变

Extended X-ray absorption fine structure measurements of laser-shocked V and Ti and crystal phase transformation in Ti.

作者信息

Yaakobi B, Meyerhofer D D, Boehly T R, Rehr J J, Remington B A, Allen P G, Pollaine S M, Albers R C

机构信息

Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.

出版信息

Phys Rev Lett. 2004 Mar 5;92(9):095504. doi: 10.1103/PhysRevLett.92.095504.

DOI:10.1103/PhysRevLett.92.095504

PMID:15089486

Abstract

Extended x-ray absorption fine structure (EXAFS), using a laser-imploded target as a source, can yield the properties of laser-shocked metals on a nanosecond time scale. EXAFS measurements of vanadium shocked to approximately 0.4 Mbar yield the compression and temperature in good agreement with hydrodynamic simulations and shock-speed measurements. In laser-shocked titanium at the same pressure, the EXAPS modulation damping is much higher than is warranted by the predicted temperature increase. This is shown to be due to the alpha-Ti to omega-Ti crystal phase transformation, known to occur below approximately 0.1 Mbar for slower shock waves.

摘要

利用激光内爆靶作为源的扩展X射线吸收精细结构（EXAFS），可以在纳秒时间尺度上得出激光冲击金属的特性。对冲击到约0.4兆巴的钒进行EXAFS测量，得出的压缩和温度与流体动力学模拟及冲击速度测量结果吻合良好。在相同压力下对激光冲击的钛进行测量时，EXAPS调制阻尼比预测的温度升高所应有的值高得多。结果表明，这是由于α-Ti到ω-Ti的晶体相变，已知在约0.1兆巴以下，对于较慢的冲击波会发生这种相变。