A cryopump includes a cryopump container, a pressure sensor that measures a pressure in the cryopump container and generates time-series pressure data indicating the measured pressure, a vent valve that is provided on the cryopump container, is electrically operable to open and close, and is capable of being mechanically opened by a differential pressure between inside and outside the cryopump container, and a controller that, during cryopump regeneration, detects stabilization of the measured pressure based on the time-series pressure data from the pressure sensor and controls the vent valve to open upon detection of the stabilization of the measured pressure.

A cryopump includes a cryopump container, a pressure sensor that measures a pressure in the cryopump container and generates time-series pressure data indicating the measured pressure, a vent valve that is provided on the cryopump container, is electrically operable to open and close, and is capable of being mechanically opened by a differential pressure between inside and outside the cryopump container, and a controller that, during cryopump regeneration, detects stabilization of the measured pressure based on the time-series pressure data from the pressure sensor and controls the vent valve to open upon detection of the stabilization of the measured pressure.

A method of regenerating a cryopump includes: supplying a purge gas to a cryopump in order to heat a cryopanel to a first temperature zone higher than the melting point of water; suspending supply of the purge gas to the cryopump while a cryopanel temperature is in the first temperature zone, and heating the cryopanel from the first temperature zone to a second temperature zone higher than a purge gas temperature.

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 ?m; 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 ?m. 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 ?m 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.

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 ?m; 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 ?m. 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 ?m 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.

A cryopump includes a cryopump flange for attachment to the flange on a gate valve, and an annular baffle that axially extends toward the gate valve from the cryopump flange such that the annular baffle forms an annular orifice in association with a valve plate component of the gate valve. The annular orifice may be defined between an upper surface of the annular baffle and the valve plate.

A cryopump includes a cryopump flange for attachment to the flange on a gate valve, and an annular baffle that axially extends toward the gate valve from the cryopump flange such that the annular baffle forms an annular orifice in association with a valve plate component of the gate valve. The annular orifice may be defined between an upper surface of the annular baffle and the valve plate.

Cryogenic pump apparatuses include nanostructure material to achieve an ultra-high vacuum level. The nanostructure material can be mixed with either an adsorbent material or a fixed glue layer which is utilized to fix the adsorbent material. The nanostructure material's good thermal conductivity and adsorption properties help to lower working temperature and extend regeneration cycle of the cryogenic pumps.

Cryogenic pump apparatuses include nanostructure material to achieve an ultra-high vacuum level. The nanostructure material can be mixed with either an adsorbent material or a fixed glue layer which is utilized to fix the adsorbent material. The nanostructure material's good thermal conductivity and adsorption properties help to lower working temperature and extend regeneration cycle of the cryogenic pumps.

A cryopump includes a cryopanel, a cryocooler which is configured to cool the cryopanel, and includes a cryocooler motor configured to drive the cryocooler and a cryocooler inverter configured to control an operating frequency of the cryocooler motor, and a control unit configured to control the cryocooler to perform a cool-down operation by which a temperature of the cryopanel is decreased from room temperature to a standard operating temperature. The control unit includes an operating frequency determination unit configured to determine an operating frequency of the cryocooler motor within an operating frequency range having an upper limit operating frequency and outputs the operating frequency to the cryocooler inverter, and an upper limit adjustment unit configured to decrease the upper limit operating frequency based on a decrease in a temperature of the cryopanel during the cool-down operation.