Abstract: In a cryogenic refrigerator having a precooling refrigerating circuit including a cryostat for cooling and maintaining a cryogenic working apparatus which is operated at a very low temperature level, expander for expanding refrigerant gas, such as helium gas, and a J-T circuit for generating cold by Joule-Thomson expanding refrigerant gas precooled by the precooling refrigerating circuit, the present invention prevents the working vibration of the expander from unduly effecting the cryogenic working apparatus and to maintain the cryogenic working apparatus at a very low temperature level for many hours, even while the precooling refrigerating circuit is stopped, thereby enabling a stabilized operation of the cryogenic working apparatus to be performed.

Abstract: In cryogenic refrigerator provided with a cryostat having a low temperature level maintaining part for cooling and maintaining a part to be cooled at a very low temperature level and an expander which is fitted in the low temperature level maintaining part of the cryostat and generates cold in the low temperature level maintaining part by expanding refrigerant gas compressed by a compressor, vibration of the working expander is prevented from being transmitted to the part to be cooled by fixing and supporting the part to be cooled to the cryostat, separately from the expander, thereby minimizing the bad influence or vibration on a cryogenic working apparatus which is sensitive to vibration and by integrally supporting the part to be cooled and the expander to the crystat. In this way, the necessity of supporting the part to be cooled and the expander individually is eliminated and installation of the refrigerator is easy.

Abstract: In a cryogenic refrigerator having a precooling refrigerating circuit including a cryostat for cooling and maintaining a cryogenic working apparatus which is operated at a very low temperature level, an expander for expanding refrigerant gas, such as helium gas, and a J-T circuit for generating cold by Joule-Thomson expanding refrigerant gas precooled by the precooling refrigerating circuit, the present invention prevents the working vibration of the expander from unduly effecting the cryogenic working apparatus and to maintain the cryogenic working apparatus at a very low temperature level for many hours, even while the precooling refrigerating circuit is stopped thereby enabling a stabilized operation of the cryogenic working apparatus to be performed.