SIMULATION OF GAMMA RAY DOSE RATES AND SPECTRA

THE WHITE SANDS MISSILE RANGE GAMMA RAY FACILITY IS USED TO QUALIFY MILITARY EQUIPMENT FOR RADIATION HARDNESS. ISOTOPIC SOURCES OF 60 CO AND 137 CS ARE USED TO PRODUCE INTENSE GAMMA RAY FIELDS THAT ALLOW TESTING OF ELECTRONIC SYSTEMS IN ENVIRONMENTS THAT APPROXIMATE ANTICIPATED NUCLEAR BATTLEFIELD CONDITIONS. RECENTLY IT HAS BECOME CLEAR THAT DOSE ENHANCEMENT EFFECTS PRODUCED BY A LOW ENERGY COMPONENT IN THE RADIATION FIELD MAKES THESE TESTS DIFFICULT TO RELATE TO THE FUNDAMENTAL DAMAGE MECHANISMS OR TO THE RESULTS OF TESTS AT OTHER FACILITIES. TO CLARIFY THIS SITUATION AND TO REESTABLISH TEST STANDARDS ON A SOUND BASIS, RESEARCHERS AT THE TESTING FACILITY NEED ACCURATE INFORMATION ON THE SPECTRAL AND DIRECTIONAL PROPERTIES OF THE RADIATION FIELD. WE PROPOSED TO RESEARCH THESE ISSUES, BEGINNING IN PHASE I WITH A MONTE CARLO CALCULATION OF THE GAMMA RAY SPECTRUM AT THE FACILITY. IN PHASE II WE WILL EXTEND OUR RESEARCH TO EVALUATE THE DETAILED INTERACTION MECHANISMS TO SPECIFY SYSTEMS AND ALSO CALCULATE THE EXPECTED EFFECTS OF SUGGESTED CHANGES TO THE FACILITY.