Li L, Whitaker M L, Weidner D J
Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100, USA.
Rev Sci Instrum. 2018 Aug;89(8):086105. doi: 10.1063/1.5041802.
We report an experiment protocol for ultrasonic velocity measurements carried out in a synchrotron-based multi-anvil high-pressure apparatus. By adding a second reflector in the cell assembly, ultrasonic signals are significantly stabilized for experiments where samples experience structural changes such as phase transition or partial melting. Features of the elastic wave can be calculated from acoustic impedance allowing us to evaluate the possible interference between the sample reflection and other internal multiple reflections. This new protocol allows various forms of samples including cold-pressed powder samples, for which grain size and porosity can be monitored and controlled during the annealing process.
我们报告了一种在基于同步加速器的多砧高压装置中进行超声速度测量的实验方案。通过在样品池组件中添加第二个反射器，对于样品经历诸如相变或部分熔化等结构变化的实验，超声信号得到了显著稳定。弹性波的特征可以从声阻抗计算得出，这使我们能够评估样品反射与其他内部多次反射之间可能的干扰。这种新方案允许使用各种形式的样品，包括冷压粉末样品，在退火过程中可以监测和控制其粒度和孔隙率。
