Cryogenic refrigerator and heating method for pulse tube cryocooler

A heating method for a pulse tube cryocooler, comprising:

• rotating the pulse tube cryocooler to be changed from a cooling posture to a heating posture;
• and
• heating the pulse tube cryocooler in the heating posture,
• wherein when the pulse tube cryocooler is in the cooling posture, an inclination angle formed between a vertical line and a center axis of a pulse tube is a first angle, and when the pulse tube cryocooler is in the heating posture, the inclination angle is a second angle,
• wherein in a case where the inclination angle formed when a cold end of the pulse tube faces vertically downward is defined as zero degrees and the inclination angle formed when the cold end of the pulse tube faces vertically upward is defined as 180 degrees, the second angle is larger than the first angle;
• and
• wherein in the heating posture, the pulse tube cryocooler is heated.

A cryogenic refrigerator comprising:

• a pulse tube cryocooler including a pulse tube;
• and
• a pulse tube cryocooler rotating mechanism comprising a motor that rotatably supports the pulse tube cryocooler allowing it to be changed from a cooling posture to a heating posture,
• wherein when the pulse tube cryocooler is in the cooling posture, an inclination angle formed between a vertical line and a center axis of the pulse tube is a first angle, and when the pulse tube cryocooler is in the heating posture, the inclination angle is a second angle,
• wherein in a case where the inclination angle formed when a cold end of the pulse tube faces vertically downward is defined as zero degrees and the inclination angle formed when the cold end of the pulse tube faces vertically upward is defined as 180 degrees, the second angle is larger than the first angle;
• and
• wherein in the heating posture, the pulse tube cryocooler is heated.