Münster 1997 – scientific programme
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TT: Tiefe Temperaturen
TT 6: Postersitzung I: Mesoskopie(1-21), amorphe Metalle und Defektsysteme(22-29), Kryotechnik, Kernmagnetismus(30-37), festes N2(38), Quantenflüssigkeiten und -kristalle(39-48), dünne supraleitende Filme(49-68), schwere Fermionen und Kondosysteme(69-92), Fullerene(93-94)
TT 6.32: Poster
Tuesday, March 18, 1997, 09:30–13:00, Z1
A small sized Cold-Valve for Operation in Superfluid Helium — •K. Taubenreuther1, V. Chagovets2, P. Schmidt1, M. Huebner1, J. Leib1, and G. Eska1 — 1Physikalisches Institut, Universität Bayreuth, D-95440 Bayreuth — 2Verkin Institute, Ukrainian Academy of Sciences, Karkov 310164, Ukraine
Cold valves are a necessity for many experiments with normal and superfluid Helium. In the most common designs Helium itself is used as the hydraulic fluid which operates the valve by moving a needle. The positioning of this needle is sometimes not very reproducible because flexible metallic balgs are used in the design. We describe several designs of small size which are using membranes instead of balgs to operate the needle with a pressure difference of about 1 bar. Depending on the needle- and membrane-material such devices can be built superleak tight with a leak-rate less 10−10mbar l/sec. Even many cool-down- and open/close-cycles have not deteriorated this value. Difficulties and performances of different types of such valves are discussed.