Cryotron operating point stabilization loop

Claim 1

IN A CRYOGENIC SYSTEM, LIQUID REFRIGERANT MEANS, AN ARRAY OF CRYOTRON DEVICES WHOSE OPERATION PARAMETERS VARY WITH TEMPERATURE AND A MONITORING CRYOTRON WHOSE OPERATION PARAMETERS VARY WITH TEMPERATUE ARRANGED WITHIN SAID LIQUID REFRIGERANT MEANS SO AS TO BE MAINTAINED AT A SAME OPERATING TEMPERATURE, THE OPERATION OF SAID ARRAY INTRODUCING HEAT LOSS WITHIN SAID LIQUID REFRIGERANT MEANS WHEREBY THE OPERATING TEMPERATURE OF SAID ARRAY AND SAID MONITORING CRYOTRON IS VARIED, FIRST MEANS FOR PERIODICALLY APPLYING SIGNALS OF TIME-VARYING AMPLITUDE TO SAID MONITORING CRYOTRON, THE AMPLITUDE AND DURATION OF SAID SIGNALS BEING AT LEAST SUFFICIENT TO SWITCH SAID MONITORING CRYOTRON, THE AMPLITUDE OF SAID SIGNALS REQUIRED TO SWITCH SAID MONITORING CRYOTRON BEING A FUNCTION OF OPERATING TEMPERATURE, AND MEANS RESPONSIVE TO SAID MONITORING CRYOTON FOR STABILIZING THE OPERATION PARAMETERS, OF SAID ARRAY IN ACCORDANCE WITH VARIATIONS IN THE DURATION OF SAID TIME-VARYING SIGNALS REQUIRED TO SWITCH SAID MONITORING CRYOTON.