The disclosure describes various aspects of a vibrationally isolated cryogenic shield for local high-quality vacuum. More specifically, the disclosure describes a cryogenic vacuum system replicated in a small volume in a mostly room temperature ultra-high vacuum (UHV) system by capping the volume with a suspended cryogenic cold finger coated with a high surface area sorption material to produce a localized extreme high vacuum (XHV) or near-XHV region. The system is designed to ensure that all paths from outgassing materials to the control volume, including multiple bounce paths off other warm surfaces, require at least one bounce off of the high surface area sorption material on the cold finger. The outgassing materials can therefore be pumped before reaching the control volume. To minimize vibrations, the cold finger is only loosely, mechanically connected to the rest of the chamber, and the isolated along with the cryogenic system via soft vacuum bellows.

A cryopump includes a cryocooler which includes a first cooling stage, a second cooling stage having a tip stage surface, and a cryocooler structure portion which extends in an axial direction from the first cooling stage to the second cooling stage, a radiation shield which is thermally coupled to the first cooling stage and includes a shield front end which defines a shield main opening and a shield bottom portion having a cryocooler insertion hole which receives the cryocooler structure portion such that the tip stage surface faces the shield main opening, a cap member which surrounds the tip stage surface in a non-contact manner and is thermally coupled to the first cooling stage, and a second stage cryopanel which is disposed between the cap member and the first cooling stage in the axial direction and is thermally coupled to the second cooling stage.

A cryopump includes a cryocooler which includes a first cooling stage, a second cooling stage having a tip stage surface, and a cryocooler structure portion which extends in an axial direction from the first cooling stage to the second cooling stage, a radiation shield which is thermally coupled to the first cooling stage and includes a shield front end which defines a shield main opening and a shield bottom portion having a cryocooler insertion hole which receives the cryocooler structure portion such that the tip stage surface faces the shield main opening, a cap member which surrounds the tip stage surface in a non-contact manner and is thermally coupled to the first cooling stage, and a second stage cryopanel which is disposed between the cap member and the first cooling stage in the axial direction and is thermally coupled to the second cooling stage.

The disclosure describes various aspects of a vibrationally isolated cryogenic shield for local high-quality vacuum. More specifically, the disclosure describes a cryogenic vacuum system replicated in a small volume in a mostly room temperature ultra-high vacuum (UHV) system by capping the volume with a suspended cryogenic cold finger coated with a high surface area sorption material to produce a localized extreme high vacuum (XHV) or near-XHV region. The system is designed to ensure that all paths from outgassing materials to the control volume, including multiple bounce paths off other warm surfaces, require at least one bounce off of the high surface area sorption material on the cold finger. The outgassing materials can therefore be pumped before reaching the control volume. To minimize vibrations, the cold finger is only loosely, mechanically connected to the rest of the chamber, and the isolated along with the cryogenic system via soft vacuum bellows.

The cryogenic trapping system traps organic arsenicals within a centrally-positioned cryotrap body and allows inorganic arsenical to flow through the cryotrap body. As a hydride gas is directed into the central cryotrap body, the gas is cooled by a pair of Peltier units that sandwich the cryotrap body so that the cold side of each of the Peltier units abuts the cryotrap body. The hot side of each Peltier unit abuts a heat exchangerwhich cools the Peltier unit. In the preferred embodiment, organic arsenicals are trapped in a sorbent bed within the cryotrap body.

The cryogenic trapping system traps organic arsenicals within a centrally-positioned cryotrap body and allows inorganic arsenical to flow through the cryotrap body. As a hydride gas is directed into the central cryotrap body, the gas is cooled by a pair of Peltier units that sandwich the cryotrap body so that the cold side of each of the Peltier units abuts the cryotrap body. The hot side of each Peltier unit abuts a heat exchangerwhich cools the Peltier unit. In the preferred embodiment, organic arsenicals are trapped in a sorbent bed within the cryotrap body.

A flange for a pump comprises first and second faces and a passageway for cryogenic fluid flow extending from the first face to the second face and at least one of (1) the passageway is for a pipe and comprises a first portion of a first diameter and a second portion of a second diameter greater than the first diameter, wherein when the pipe has an outer diameter that is smaller than the second diameter a gap is formed between the pipe and the passageway where the pipe passes through the second portion; and (2) a first annular groove in one of the first face and the second face and extending around the passageway, wherein the first annular groove in cooperation with the passageway forms a bellows. The gap and bellows increase the thermal resistance between the passageway and the flange, and the bellows allows for flexure during thermal contractions of the flange reducing thermal stress on welded fluid seals.

A flange for a pump comprises first and second faces and a passageway for cryogenic fluid flow extending from the first face to the second face and at least one of (1) the passageway is for a pipe and comprises a first portion of a first diameter and a second portion of a second diameter greater than the first diameter, wherein when the pipe has an outer diameter that is smaller than the second diameter a gap is formed between the pipe and the passageway where the pipe passes through the second portion; and (2) a first annular groove in one of the first face and the second face and extending around the passageway, wherein the first annular groove in cooperation with the passageway forms a bellows. The gap and bellows increase the thermal resistance between the passageway and the flange, and the bellows allows for flexure during thermal contractions of the flange reducing thermal stress on welded fluid seals.

A cryopump includes: a cryopump vacuum chamber; a cryocooler; a vibration-proof structure that connects the cryocooler to the cryopump vacuum chamber; and a removable restraint that connects the cryocooler to the cryopump vacuum chamber in parallel to the vibration-proof structure and restrains both of expansion and contraction of the vibration-proof structure between the cryocooler and the cryopump vacuum chamber.

A cryopump includes: a cryopump vacuum chamber; a cryocooler; a vibration-proof structure that connects the cryocooler to the cryopump vacuum chamber; and a removable restraint that connects the cryocooler to the cryopump vacuum chamber in parallel to the vibration-proof structure and restrains both of expansion and contraction of the vibration-proof structure between the cryocooler and the cryopump vacuum chamber.