Systems and methods are provided that facilitate forming and maintaining FRCs with superior stability as well as particle, energy and flux confinement and, more particularly, systems and methods that facilitate forming and maintaining FRCs with elevated system energies and improved sustainment utilizing neutral beam injectors with tunable beam energy capabilities.

A cryopump includes a cryocooler; a cryopanel cooled by the cryocooler; a cryopump container supporting the cryocooler and accommodating the cryopanel; a temperature sensor that measures a temperature of the cryopanel and outputs a measured temperature signal indicating the temperature; a pressure sensor that measures an internal pressure of the cryopump container and outputs a measured pressure signal indicating the internal pressure; a pressure rise rate comparator that compares a pressure rise rate of the cryopump container with a first pressure rise rate threshold; and a cryocooler controller that controls the cryocooler to lower the temperature of the cryopanel. The pressure rise rate comparator compares the pressure rise rate of the cryopump container with a second pressure rise rate threshold. The second pressure region is lower than the first pressure region. The second pressure rise rate threshold is smaller than the first pressure rise rate threshold.

There is provided a cryopump including a cryocooler, a cryopanel that is cooled by the cryocooler, a cryopump container that includes a container body, which accommodates the cryopanel, and a cryocooler accommodating tube of which one end is coupled to the container body and the other end is fixed to the cryocooler and into which the cryocooler is inserted, a vent valve for exhausting a fluid from the cryopump container, a first exhaust passage that includes a first exhaust port provided in the container body, is disposed outside the cryopump container, and connects the first exhaust port to the vent valve, and a second exhaust passage that includes a second exhaust port provided in the cryocooler accommodating tube, connects the second exhaust port to the vent valve, and merges with the first exhaust passage between the first exhaust port and the vent valve.

A cryopump includes: a cryopump container including a container body defining a cryopump intake port and extending axially and tubularly from the cryopump intake port, and a cryocooler accommodation cylinder connected to a side portion of the container body and extending transversely; a cryocooler fixed to the cryocooler accommodation cylinder and extending transversely within the cryopump container; a plurality of cryopanels thermally coupled to the second cooling stage of the cryocooler, capable of adsorbing a non-condensable gas, and axially arranged between the cryopump intake port and a bottom portion of the container body; and a purge gas inlet installed in the container body below the cryocooler accommodation cylinder to blow a purge gas to a distal portion of at least one of the cryopanels.

A cryopump includes: a cryopump container including a container body defining a cryopump intake port and extending axially and tubularly from the cryopump intake port, and a cryocooler accommodation cylinder connected to a side portion of the container body and extending transversely; a cryocooler fixed to the cryocooler accommodation cylinder and extending transversely within the cryopump container; a plurality of cryopanels thermally coupled to the second cooling stage of the cryocooler, capable of adsorbing a non-condensable gas, and axially arranged between the cryopump intake port and a bottom portion of the container body; and a purge gas inlet installed in the container body below the cryocooler accommodation cylinder to blow a purge gas to a distal portion of at least one of the cryopanels.

A flow restrictor for restricting a flow rate of gas flowing into a cryopump and the cryopump are disclosed. The flow restrictor is configured to be mounted in an inlet of the cryopump, the flow restrictor comprising: an inlet component for providing a gas flow path into the cryopump; a shielding plate mounted to at least partially obscure the gas flow path though the inlet component; and an intermediate component linking the shielding plate to the inlet component, the intermediate component comprising at least one aperture, the at least one aperture defining at least one gas flow path into the cryopump The shielding plate is configured to shield the gas flow path through the inlet component such that when mounted on the cryopump there is no direct line of sight path through the inlet component to a cryopanel within the cryopump.

A flow restrictor for restricting a flow rate of gas flowing into a cryopump and the cryopump are disclosed. The flow restrictor is configured to be mounted in an inlet of the cryopump, the flow restrictor comprising: an inlet component for providing a gas flow path into the cryopump; a shielding plate mounted to at least partially obscure the gas flow path though the inlet component; and an intermediate component linking the shielding plate to the inlet component, the intermediate component comprising at least one aperture, the at least one aperture defining at least one gas flow path into the cryopump The shielding plate is configured to shield the gas flow path through the inlet component such that when mounted on the cryopump there is no direct line of sight path through the inlet component to a cryopanel within the cryopump.

Apparatus for compressing cryogenic fluid in at least one compression stage comprising at least one piston and at least one sleeve delimiting at least one compression chamber, a shaft that is able to move in translation along a longitudinal axis (A), the shaft being connected to the piston(s) or sleeve(s) and being able to move with an alternating movement in two opposite directions to ensure phases of compression and intake of fluid into the at least one compression chamber by moving the at least one piston and the at least one sleeve in a relative manner, characterized in that the shaft comprises a portion of reduced cross section in the longitudinal direction (A), said portion of reduced cross section separating two adjacent parts of the shaft, the shaft also comprising at least one linking element made of material that is less thermally conductive than the constituent material of the shaft, in particular a composite material, said at least one linking element having two ends connected respectively to the two adjacent parts of the shaft.

Apparatus for compressing cryogenic fluid in at least one compression stage comprising at least one piston and at least one sleeve delimiting at least one compression chamber, a shaft that is able to move in translation along a longitudinal axis (A), the shaft being connected to the piston(s) or sleeve(s) and being able to move with an alternating movement in two opposite directions to ensure phases of compression and intake of fluid into the at least one compression chamber by moving the at least one piston and the at least one sleeve in a relative manner, characterized in that the shaft comprises a portion of reduced cross section in the longitudinal direction (A), said portion of reduced cross section separating two adjacent parts of the shaft, the shaft also comprising at least one linking element made of material that is less thermally conductive than the constituent material of the shaft, in particular a composite material, said at least one linking element having two ends connected respectively to the two adjacent parts of the shaft.

The present invention provides a rare earth cold accumulating material particle comprising a rare earth oxide or a rare earth oxysulfide, wherein the rare earth cold accumulating material particle is composed of a sintered body; an average crystal grain size of the sintered body is 0.5 to 5 μm; a porosity of the sintered body is 10 to 50 vol. %; and an average pore size of the sintered body is 0.3 to 3 μm. Further, it is preferable that the porosity of the rare earth cold accumulating material particle is 20 to 45 vol. %, and a maximum pore size of the rare earth cold accumulating material particle is 4 μm or less. Due to this structure, there can be provided a rare earth cold accumulating material having a high refrigerating capacity and a high strength.