Bakeable cryopump

Claim 2

A bakeable cryopump comprising in combination: a flange suitable for mounting said cryopump to a vacuum chamber; a generally cylindrical refrigerator housing fixed to said flange, said refrigerator housing adapted and arranged to receive a two-stage displacer-expander refrigerator head whereby a coldest stage of said refrigerator head can be brought in thermal contact with a closed end of said refrigerator housing, said refrigerator housing further adapted and arranged in combination with a thermal transfer media contained in said housing at approximately 1 atmosphere pressure to thermally contact a warmer stage of said refrigerator; at least one cryopanel fixed to said closed end of the refrigerator housing whereby said refrigerator head can be readily removed from said refrigerator housing and said cryopump housing heated to temperatures above 200°C under vacuum conditions to remove adsorbed gases from said cryopanel.

Claim 3

A cryopump according to Claim 1 wherein said thermal transfer media is helium.

Claim 4

A cryopump according to Claim 1 wherein there is included two cryopanels on said closed end of said refrigerator housing one of said panels having disposed thereon an adsorbent.

Claim 5

A cryopump according to Claim 1 or 3 wherein said cryopanels are fabricated from a highly conductive metal, said panels plated with a radiation reflective metal on the outside surface and having a radiation absorbing coating on the inside surface.

Claim 6

A cryopump according to Claim 1 wherein said refrigerator housing is fabricated from stainless steel with copper heat station.

Claim 7

A cryopump according to Claim 1 wherein a cryopanel is fixed to the portion of said refrigerator housing in thermal contact with the warmer stage of said refrigerator and is of a generally cylindrical shape extending beyond the first end of said refrigerator housing with an inwardly turned flange shaped portion on said terminating end.

Claim 8

A cryopump according to Claim 1 wherein the materials of construction are selected to minimize outgassing at ultra high vacuum levels.

Claim 9

A bakeable cryopump comprising in combination: a generally cylindrical cryopump housing having a first end containing a flange suitable for mounting said cryopump housing to a vacuum chamber and a second end having thereon a closure; said closure having a generally cylindrical refrigerator housing extending longitudinally inside said housing from said second end toward said first end, said refrigerator housing adapted and arranged to receive a two-stage displacer-expander refrigerator head whereby a first or cold stage of said refrigerator head can be brought in contact with a closed end of said refrigerator housing, said refrigerator housing further adapted and arranged to contact a second stage of said refrigerator in a slip fit manner; at least one cryopanel fixed to said closed end and a second cryopanel fixed to the portion of the refrigerator housing where said refrigerator head engages said refrigerator housing in the slip fit manner; whereby said refrigerator head can be readily removed from said refrigerator housing and said cryopump housing heated to temperatures above 200°C under vacuum conditions to remove pumped gases from said cryopanels.

Claim 10

A bakeable cryopump comprising in combination: a generally cylindrical cryopump housing having a first end containing a flange suitable for mounting said cryopump housing to a vacuum chamber and a second end having thereon a closure; said closure having a generally cylindrical refrigerator housing extending longitudinally inside said housing from said second end toward said first end, said refrigerator housing adapted and arranged to receive a two-stage displacer-expander refrigerator head whereby a first or cold stage of said refrigerator head can be brought in contact with a closed end of said refrigerator housing, said refrigerator housing further adapted and arranged to contact a second stage of said refrigerator in a slip fit manner; at least one cryopanel fixed to said closed end and a second cryopanel fixed to the portion of the refrigerator housing where said refrigerator head engages said refrigerator housing in the slip fit manner; whereby said refrigerator head can be readily removed from said refrigerator housing and said cryopump housing heated to temperatures above 200°C under vacuum conditions to remove pumped gases from said cryopanels.

Claim 11

A cryopump according to Claim 8 wherein said refrigerator housing includes means to surround said refrigerator with a thermal transfer media at essentially 0 psig.

Claim 12

A cryopump according to Claim 8 wherein there is included two cryopanels on said closed end of said refrigerator housing one of said panels having disposed thereon an adsorbent.

Claim 13

A cryopump according to Claim 8 or 10 wherein said cryopanels are fabricated from a material of high thermal conductivity, said panels plated with a radiation reflective metal on the outside surface and having a radiation absorbing coating on the inside surface.

Claim 14

A cryopump according to Claim 8 wherein said cryopump housing is fabricated from stainless steel.

Claim 15

A cryopump according to Claim 8 wherein said cryopanel fixed to the slip fit portion of said refrigerator housing is of a generally cylindrical shape extending toward the first end of said housing terminating before the first end of said housing and having an inwardly turned flange shaped portion on said terminating end.

Claim 16

A cryopump according to Claim 8 wherein said refrigeration is transferred from said refrigerator head to said housing by means of convective heat transfer.