Method of Isentropically Compressing Materials to Several Megabars

Abstract

This paper describes a new method of compressing materials up to pressures of several megabars. A high-intensity magnetic field, obtained by magnetic flux compression, is used to compress a sample contained in a metallic tube. The compression of the sample is slow enough to avoid the generation of shock waves which allows the process to be isentropic. This paper describes the apparatus and several experiments with Lucite samples. Evidence that Lucite was isentropically compressed to a specific volume of about 0.25 is included. The pressure reached is estimated to be ~4 Mbar.

Use of Pulsed Radiography for Investigation of Equations of State of Substances at Megabar Pressures

“…A compression of an aluminum sample, located on the MC-1 generator axis, was studied using the radiography in a paper [5]. This allowed determining a range of characteristic pressures (1)(2)(3)(4)(5) reached in the MC-1 based compression device. The paper [6] is devoted to an analysis of compression symmetry of a cylindrical copper tube located on an MC-1 generator axis.…”

“…The pulsed x-ray radiography method is applied especially to researches that use the MC-1 generator of super-high magnetic field as a source of pressure [2,[5][6][7]. A compression of an aluminum sample, located on the MC-1 generator axis, was studied using the radiography in a paper [5].…”

“…The method of pulsed radiography was used by different groups [1][2][3][4] to study equations of state (EOS) of hydrogen (protium) and deuterium. The pulsed x-ray radiography method is applied especially to researches that use the MC-1 generator of super-high magnetic field as a source of pressure [2,[5][6][7].…”

Design and Analysis of Isentropic Compression Experiments

“…Most of the results of more than thirty experiments have been published [3-7J together with most of the details of the field generation [4], diagnostics [4,6], and some of the design criteria [4], This paper summarizes the technique and discusses details on the compression dynamics, data reduction of the flash radiographs, and sample-containment design.…”

“…Flux compression is ideally suited for compressing matter without forming Shockwaves while effectively utilizing the energy of explosives [3,4].…”