Isentropic Compression of Condensed Hydrogen Up to Megabar Pressure

Abstract

The paper describes a device for isentropic compression of frozen gases by pressure of the ultra-high magnetic field generated by the cascade magnetocumulative generator MC-1 (MC-1 EMG). The paper provides test data on isentropic compression of solid hydrogen up to ∼ 3 Mbar. Brief description of a technique for the test data analysis is provided as well as the comparison between this data and the computation. The interest to a hydrogen equation of state within the megabar pressure range is caused by wide hydrogen spread in the universe and its presence in stars and giant planets. Also many applied problems as well as metal hydrogen manufacture can be solved by solving the problem of thermonuclear fusion. Though hydrogen has a primitive single-electron structure that in principle allows direct calculations of high-density states to be performed, the difficulties of the correct consideration for strong interparticle interaction result in construction of differing theoretical models. In these conditions it becomes important to get experimental data on hydrogen compression within the wide range of parameters. The hydrogen “cool” equation of state within the megabar pressure range is possible only with the help of anvil static technique and isentropic compression technique using the ultra-high magnetic field that has been developed at our institute. The goal of this work is plotting a “cool” hydrogen equation of state within the pressure range 1 – 4 Mbar, when thermal pressure component is negligibly small as compared to an elastic one, and full pressure in the substance practically matches the elastic pressure. This goal can be reached using the technique of condensed hydrogen isentropic compression by ultra-high magnetic filed generated by MC-1 generator. A principal schematic of the device is provided in Fig. 1.