A cryogenic cooling apparatus comprises a supply gas line and a return gas line adapted to be coupled to a compressor. A coupling element is positioned in gaseous communication with the supply and return gas lines, the coupling element being adapted in use to supply gas to a mechanical refrigerator so that the pressure of said supplied gas is modulated by the coupling element in a cyclical manner. A sensing system is used to monitor the operational state of the mechanical refrigerator and a control system modulates the frequency of the cyclical gas pressure supplied by the coupling element in accordance with the monitored operational state. The mechanical refrigerator has a first cooled stage and a second cooled stage, the second cooled stage being adapted to be coupled thermally with target apparatus to be cooled. A selectively coupleable thermal link is provided for thermally coupling the first cooled stage of the mechanical refrigerator to the second cooled stage in dependence upon the operational state of the mechanical refrigerator. A method of use of the apparatus is also disclosed. The apparatus and method have particular application in a Magnetic Resonance Imaging system.

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 with a pump inlet; a two stage refrigerator; a first stage array arranged thermally coupled to a first stage of the two stage refrigerator; and a cryopanel structure coupled to a second stage of the two stage refrigerator. Surfaces of the cryopanel structure have portions that are coated portion with an adsorbent material and other portions that are not coated with the adsorbent material.

A cryopump with a pump inlet; a two stage refrigerator; a first stage array arranged thermally coupled to a first stage of the two stage refrigerator; and a cryopanel structure coupled to a second stage of the two stage refrigerator. Surfaces of the cryopanel structure have portions that are coated portion with an adsorbent material and other portions that are not coated with the adsorbent material.

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.

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.

An object of the present invention is to improve, using a simple configuration, heat dissipation of a regenerative resistor that is disposed in a vacuum pump control device (controller) connected to a vacuum pump. The regenerative resistor disposed in the vacuum pump control device is stored in an aluminum die-cast casing. More concretely, a housing of the vacuum pump control device is prepared by aluminum die casting (metal mold casting). A regenerative resistor storing portion (aluminum die-cast casing) provided with a hollow portion is provided on a top panel of the aluminum die cast, the hollow portion being designed to have a size accommodating the entire regenerative resistor. The regenerative resistor is fitted into the hollow portion, and an opening section of the hollow portion is sealed with an aluminum sheet of the same material as that of the casing. In this manner, the regenerative resistor can removably be stored in the aluminum die-cast casing.