Device for building-up high pressure

In a device for building up pressure comprising a pair of identical coaxial dies facing each other, the dies being capable of being drawn together and having faces, outer peripheries and central sections, adapted to receive between the sections a specimen to be studied;

• a solid medium arranged between the central sections and adapted to surround the specimen being studied, the solid medium being capable of transmitting to the specimen the pressure build-up in the solid medium when the dies are being drawn together and means for confining the solid medium in the central sections when the dies are being drawn together;
• the improvement wherein the means for confining the solid medium consists of at least one annular circular groove located identically in each die in the face thereof concentrically outwardly of the central section and inwardly of the outer periphery of each die, said grooves being adapted to be filled with the solid medium and being defined by depressions whose inner and outer sides have annular raised arms, said grooves forming a toroidal space filled with the solid medium upon the closure of the dies, the outer side of the outermost annular circular groove of said at least one groove in each die when closed upon said solid medium being open to atmospheric pressure;
• said solid medium being a unitary body extending from the central section through to the outer side of said outermost circular groove;
• wherein the solid medium is selected from the group consisting of pyrophyllite, catlinite, or their combination.