Solenoid controlled cold head for a cryogenic cooler

A solenoid controlled cold head for a closed cycle cryogenic cooler comprising:

• an enclosed cooler housing having a cold end and an ambient temperature end;
• a free moving regenerator-displacer having a regenerator matrix therein positioned within said cold end and having a pneumatic piston rigidly attached to said regenerator-displacer at said ambient temperature end wherein said pneumatic piston extends into an average pressure pneumatic volume;
• an effective pneumatic piston cross-sectional area on a portion of said pneumatic piston between said regenerator-displacer and said pneumatic volume that provides movement means for said free moving regenerator-displacer within said cooler housing when differential pressures are applied thereacross;
• a compressor and compressor driving means mechanically linked together for providing alternating pressure waves of a light gas enclosed within said closed cycle and in communication with said regenerator-displacer for cyclically applying differential pressures across said effective pneumatic piston cross-sectional area to move said regenerator-displacer reciprocally within said cooler housing;
• and
• a control means comprising a synchronizing means sensing and reacting to the phase of said alternating pressure waves and solenoid control means responding to said synchronizing means for moving said pneumatic piston and said regenerator-displacer rigidly attached thereto when said alternating pressure waves are at their maximum and minimum for providing in-phase operation causing more work and more refrigeration at said cold end.