| 摘要 |
<p>1291730 Solidifying gases INSTITUT FUR PLASMAPHYSIK GmbH 16 Dec 1969 [16 Dec 1968] 61307/69 Heading F4P [Also in Division H1] A thin disc of solid hydrogen, for use as a pulse laser or particle radiation target, is prepared by solidifying hydrogen within an orifice 36 in a metal plate 34. The plate is fixed to a copper black 20 cooled by liquid helium in a cooling coil 22 and is positioned within a vacuum chamber 10 which may be evacuated by a diffusion pump. To form the disc the chamber is first evacuated and a cup-shaped member 46 placed over the plate 34 and block 20, and hydrogen gas is introduced into the space enclosed via a part 44. Liquid helium is then passed through coil 22 and hydrogen condenses on the plate and forms a liquid film in orifice 36 which is slowly solidified. The cup member 46 is then withdrawn, the residual hydrogen gas pumped away, and the disc may be irradiated through lenses 50. The orifice 34 is open at one side to allow measurement of the thickness of the disc. Solidifiable gases other than hydrogen may be used, as well as coolants other than helium.</p> |
