Cryostat

A cryostat comprising:

• a room temperature vessel comprising a room temperature tank, an outer neck tube and a sealing head, the outer neck tube communicating with the room temperature tank, a first opening being disposed at the room temperature tank, the sealing head being disposed to cover the room temperature tank, a second opening and a third opening being disposed at the sealing head, the first opening being in communication with the third opening, the outer neck tube passing through the second opening to be exposed outside the sealing head, and an outer circumference of the outer neck tube being in sealingly contact with the second opening of the sealing head;
• a low temperature vessel comprising a low temperature tank, an inner neck tube and a liquefaction chamber, the inner neck tube being independent of the liquefaction chamber and communicating with the low temperature tank, the low temperature vessel being housed inside the room temperature tank, part of the inner neck tube being located inside the outer neck tube, the liquefaction chamber being partially located inside the room temperature tank, and part of the liquefaction chamber passing through the first opening;
• and
• a refrigeration mechanism comprising a device panel and a refrigeration device, the device panel being disposed at the sealing head and having through holes respectively in communication with the second opening and the third opening, the refrigeration device being installed to the device panel, the refrigeration device comprising a body and a cold finger, the body being disposed at the device panel, and the cold finger being connected with the body and extending into the liquefaction chamber.