Abstract A cryogenic pumping device for the creation of very high vacuum, comprising means for collecting gases at very low temperature, said collecting means including adsorption means and condensation means, the condensation means being located upstream of the adsorption means with respect to the travel of the gases, the whole being housed in a casing cooled to a moderately low temperature and formed, on the side of the passage communicating with the chamber to be pumped, by a baffle adapted to form a screen against external radiation. The adsorption means are mounted on an extension of a metal wall which forms the condensation means, each metal wall being adjacent to a segment of a cooling coil through which is circulated a fluid at very low temperature.
A cryopump as claimed in claim 1, in which at least a part of said condensation means is constituted by a plurality of fins disposed substantially radially in a cylindrical annular ring around said adsorption means.
Claim 2
Dependent Claim
35 words
A cryopump as claimed in claim 2, in which said adsorption means comprise an adsorbent carried by a radial extension of said condensation fins, at least in part, towards the interior of said pumping device.
Claim 3
Dependent Claim
22 words
A cryopump as claimed in claim 3, in which said adsorbent is constituted by a sintered metal, and preferably by sintered nickel.
Claim 4
Dependent Claim
51 words
A cryopump as claimed in claim 2, in which said condensation fins form oblique walls with a coupling or folding line parallel to the axis of said cylindrical annular ring of fins, said walls being all identically inclined with respect to an axial plane passing through said coupling or folding line.
Claim 5
Dependent Claim
37 words
A cryopump as claimed in claim 5, in which said fins are brazed at their extremities on two annular end plates, supported externally by two solid plate-discs, said plate-discs being fixed to each other by tie rods.
Claim 6
Dependent Claim
29 words
A cryopump as claimed in claim 6, and further comprising a heating resistance for the regeneration of the adsorbent product, said resistance being incorporated in one of said plate-discs.