Cold head, superconducting magnet, examination apparatus, and cryopump

A method for manufacturing a cold head, comprising:

• preparing a regenerator container;
• filling a first regenerator material particle group having an average particle size in a range from 200 μm to 380 μm in the regenerator container;
• filling a plurality of metal mesh materials on the first regenerator material particle group in the regenerator container;
• and
• filling a second regenerator material particle group having an average particle size in a range from 200 μm to 380 μm on the plurality of metal mesh materials in the regenerator container so that the second regenerator material particle group is partitioned with the first regenerator material particle group by the plurality of metal mesh materials,
• wherein each of the plurality of metal mesh materials has quadrangular mesh holes each having a length of a long side in a range from 1/10 to ½ of each of the average particle sizes of the first and second regenerator material particle groups,
• wherein each of the plurality of metal mesh materials has metal wires woven in a mesh form, and each of the metal wires has a wire diameter in a range from 20 μm to 90 μm,
• wherein the plurality of metal mesh materials are stacked so that positions of the mesh holes in the plurality of the metal mesh materials do not match, and
• wherein a length of one side of each of the mesh holes in one of the plurality of metal mesh materials is different from a length of one side of each of the mesh holes in another one of the plurality of the metal mesh materials.