Abstract: A heat absorber structure comprises a first wall of a good heat conducting material which has a surface with a plurality of spaced apart web portions with coolant channels defined between the web portions and a second wall of a good conducting material overlying the first wall and secured to at least portions of the web portions of the first wall. A second wall has a plurality of bulge portions formed therein in locations overlying the coolant channels. With the method of the invention the coolant channels are filled with an electrically conductive wax which is heated while the second wall is constrained in certain areas so as to form bulge portions on the second wall overlying the channels.

Abstract: An accelerating grid particularly for an ion beam, consisting of at least e orifice plate which is fastened along an elastic outer rim thereof to a support. The orifice plate or plates includes a plurality of through-holes with mutually oriented central axes, preferably directed towards a common focusing point. A plurality of slots in the elastic outer rim maintain the alignment of the orifice plate center relative to the focus point during heat-induced expansion of the plate.

Abstract: A heat absorber structure comprises a first wall of a good heat conducting material which has a surface with a plurality of spaced apart web portions with coolant channels defined between the web portions and a second wall of a good conducting material overlying the first wall and secured to at least portions of the web portions of the first wall. A second wall has a plurality of bulge portions formed therein in locations overlying the coolant channels. With the method of the invention the coolant channels are filled with an electrically conductive wax which is heated while the second wall is constrained in certain areas so as to form bulge portions on the second wall overlying the channels.

Abstract: A cold surface for cryogenic pumps in the form of a (filled/through-streamed) double wall which is acted upon by a liquid refrigeration medium, as well as to a process for the production of such a cold surface. The double wall is formed by a series of thin-walled narrow tubes which are interconnected with each other, to which there are presently attached thin axially parallel, good heat conductive metal lamellas, wherein the tube diameter, tube spacing and wall thickness, as well as the lamella thickness, with consideration being given to a minimization of the total mass of the surface, are so correlated and dimensioned with respect to each other that the temperature differences within the lamellas of the surface which is acted upon with liquid refrigeration medium at a maximum occuring heat loading will remain below 0.1.degree. K.

Abstract: A cold surface, (e.g. for use in a so-called cryopump, i.e. a cryogenic vacuum vapor pump), is formed by a reservoir for liquid hydrogen surrounded by a double-wall vessel over an intervening evacuated insulating space. The lowest points of the compartment formed between the walls of the double-wall vessel and the interior of the liquid helium reservoir are connected by a conduit provided with a valve.

Abstract: A method and apparatus which uses sputter cathode material in an ion sputter pump to discriminate between hydrogen or its isotopes and the pumped impurities by virtue of their different permeability or diffusion rates through and solubility in a film of sputtered cathode material. Iron and specific hydride-forming cathode materials are examples.

Abstract: A thermal radiation shield for cryogenic devices, especially cryogenic pu (cryopumps) comprises a stack of spaced apart plates formed preferably with a V-section configuration and lugs or openings enabling the plates to be stacked with appropriate spacers upon tubes through which a coolant is passed. The plates have an annular configuration, i.e. the V-section is closed along an annulus. The plates are so stacked as to overlap in the stacking direction, i.e. the vertex of the V of one plate is coplanar with the rim of the next plate or the vertex lies within the V of the next plate.