PORTABLE SELF-REGULATING CRYOGENIC COOLER FOR RADIATION DETECTORS

THIS PROPOSAL DESCRIBES A PROJECT FOR DEVELOPMENT OF A PORTABLE CRYOGENIC COOLER FOR RADIATION DETECTORS THAT WEIGHS LESS THAN 10 KG COMPLETE WITH A ONE WEEK SUPPLY OF CRYOGEN, IS SELF REGULATING IN CRYOGEN CONSUMPTION TO PROVIDE RAPID COOL DOWN OR RESPONSE TO TRANSIENT DEMANDS WHILE MAINTAINING MINIMUM CONSUMPTION DURING STEADY STATE OPERATION, REQUIRES NO ELECTRICAL POWER, AND HAS NO CRITICAL MOVING PARTS WHICH COULD POSE RELIABILITY OR MAINTENANCE PROBLEMS. THE LIQUID CARBON DIOXIDE USED FOR THE EXPANSION CYCLE CAN PROVIDE AN OPERATING TEMPERATURE BELOW MINUS 75 CELSIUS AND SHOULD HAVE AN ESSENTIALLY INFINITE SHELF LIFE. THE FEASIBILITY OF THE WEIGHT GOAL AND THE SELF-REGULATING CRYOGEN CONTROL HAVE ALREADY BEEN DEMONSTRATED. THE PHASE IPART OF THIS PROJECT IS FOCUSED ON FINDING SOLUTIONS TO THE PROBLEMS OF GOOD TEMPERATURE STABILITY AND THE GENERATION OF MICROPHONIC NOISE IN A HIGH RESOLUTION SI X-RAY DETECTOR. PHASE II EFFORTS WOULD CONCENTRATE ON THE DEVELOPMENT OF COMPLETE SYSTEM PROTOTYPES FOR HIGH RESOLUTION X-RAY DETECTORS AND HIGH SENSITIVITY OPTICAL DETECTORS.