An ultrahigh-pressure apparatus based on high presure produced by constraining thermal expansion and its application

考虑到它的应用，研究了一种通过限制热膨胀产生几百千兆帕斯卡的超高压的方法。在这种方法中，通过将脉冲激光应用于用透明砧压缩的样品来产生高压。用红宝石r线荧光法测量了产生的超高压。为了避免高温区域的直射光影响r线荧光的测量，采用不透明的固体材料作为压力介质，将用于测量的红宝石晶体放置在与脉冲激光照射的砧压面相对的压力面上。提出了一种光学仪器，用于调整被照亮点的位置和直径以适应样品的位置和直径，使人们能够在不损坏砧的情况下将光施加到样品上。结果表明：用能量为1 J的脉冲激光照射经过蓝宝石砧压缩的石墨样品，可观察到红宝石在1 Tpa压力下发出的R_1荧光，该荧光包含红宝石在1 Tpa压力下发出的波长；在辐射光谱测量中，有一部分石墨样品被加热到3200℃以上；根据上述实验结果计算的温度分布表明，石墨样品在4000℃以上存在较大的区域，其中大部分被认为是蒸发的；该装置产生的数百千兆帕的持续时间比所有其他传统的冲击压缩方法长几个数量级。使用蓝宝石砧的超高压设备将成为工业生产的有力工具，因为大型蓝宝石晶体易于制造。

A method of producing ultrahigh pressures to several hundred gigapascals by constraining thermal expansion is investigated taking into account its application. In this method, high pressure is generated by applying pulse laser light to a sample compressed with transparent anvils. The generated ultrahigh pressures are measured by the ruby R-line fluorescence method. In order to avoid direct light radiated from high-temperature region that prevents the measurement of the R-line fluorescence, opaque solid materials are used as pressure medium and a ruby crystal for the pressure measurement is placed on the pressure face of the anvil opposite to that irradiated by pulse laser light. An optical instrument for adjusting the position and the diameter of the illuminated spot to those of the sample is proposed which enable one to apply the light to the sample without giving damage to the anvil. The results are as follows :R_1 fluorescence light of ruby which contains wavelengths emitted from ruby under a pressure of 1 Tpa is observed when a graphite sample compressed with sapphire anvils is irradiated by a pulse laser light with a energy of 1 J ;A part of the graphite sample is shown to be heated up to temperatures above 3200 ℃ in terms of the radiation spectrum measurement;The temperature distribution calculated on the basis of the above experimental results shows that the graphite sample includes a relatively large region beyond 4000 ℃ of which the greater part is considered to be evaporated ; andthe duration of several hundred gigapascals generated in the apparatus is several orders in magnitude longer than those of all other conventional shock compression method. The ultrahigh-pressure apparatus using sapphire anvils will be a powerful tool for industrial production because a large sapphire crystal is easy to make.