Patent ID: 7308797

Claim:
A cryogenic refrigerator, comprising: a high temperature end block; a plurality of refrigerant tubes, each comprising a pair of tubes that are arranged substantially parallel to each other, each tube extending in an axial direction; a cooling stage in a form of a single body member disposed apart from the high temperature end block in a generally parallel manner with each one of the pair of tubes mounted to and between the cooling stage and the high temperature end block and respective ones of each pair of tubes being in direct fluid communication with each other through a respective gas passage formed in and through the cooling stage, the respective gas passages being in fluid isolation from one another in the cooling stage; and means for oscillating and controlling gas pressures in each respective pair of tubes, wherein the gas pressures are sufficient to cause selected ones of the pairs of refrigerant tubes to contract in the axial direction or expand in the axial direction while an equal number of remaining ones of the pairs of refrigerant tubes expand in the axial direction when the selected ones of the refrigerant tubes contract in the axial direction or contract in the axial direction when the selected ones of the refrigerant tubes expand in the axial direction, and wherein controlled oscillating gas pressures in the plurality of refrigerant tubes have phase differences, to thereby cancel vibration of the cooling stage.