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.

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.

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.

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.

According to an embodiment, a multi-cooling type cold trap according to the present disclosure includes a main body unit in which an inflow space having a material to be condensed flown therein is formed, a circulation unit which is disposed in the inflow space of the main body unit and circulates cooling water for condensing the material to be condensed, and a supply unit which supplies the cooling water to the circulation unit after lowering temperature of the cooling water in stages.

According to an embodiment, a multi-cooling type cold trap according to the present disclosure includes a main body unit in which an inflow space having a material to be condensed flown therein is formed, a circulation unit which is disposed in the inflow space of the main body unit and circulates cooling water for condensing the material to be condensed, and a supply unit which supplies the cooling water to the circulation unit after lowering temperature of the cooling water in stages.

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 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 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 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 embodiments of the present disclosure relates a cryopump including a pump housing including a suction port, a cold head located within the pump housing, a shielding element located within the pump housing and covering the cold head, a baffle at the suction port, the baffle including a gas passage with an inlet and an outlet, an orthographic projection of the baffle to the cross section of the pump housing completely covers an orthographic projection of the suction port thereto, the gas passage includes a first portion and a second portion intersecting with each other, the inlet is defined by one end of the first portion, the outlet is defined by one end of the second portion.