PERSONAL DIGITAL NEUTRON DOSIMETER

OVER A HUNDRED THOUSAND NAVY PERSONNEL AS WELL AS A LARGE NUMBER OF MILITARY AND CIVILIAN WORKERS ARE NOW REQUIRED TO WEAR NUCLEAR RADIATION DOSIMETERS. ALTHOUGH MUCH OF THE POTENTIAL EXPOSURE IS FROM NEUTRONS, PRESENTLY NO SMALL ELECTRONIC NEUTRON DOSIMETER EXISTS AND ONLY PASSIVE DEVICES ARE AVAILABLE. THIS LEADS NOT ONLY TO EXCESS SHIELDING REQUIREMENTS AND INEFFICIENT USE OF PERSONNEL, BUT ALSO TO AN INCREASED CHANCE OF INADVERTANT NEUTRON EXPOSURE. WE PROPOSE TO DEVELOP A SMALL, ROBUST, AND SENSITIVE DIGITAL PERSONAL DOSIMETER WHICH WILL ACTIVELY MEASURE NEUTRON EXPOSURE OVER A WIDE RANGE OF NEUTRON ENERGIES. THIS DEVICE WILL PROVIDE AN AUDIBLE WARNING AT HIGH EXPOSURE RATE, AND ALSO A RAPID ELECTRONIC READOUT FOR ANALYSIS OF INTEGRATED DOSE BY THE BASE COMPUTER. THE SENSING ELEMENT WILL USE THE DETECTION OF SOFT ERRORS IN A SEMICONDUCTOR MEMORY CHIP, A CONCEPT INVENTED BY THE NAVY AND WHICH IS VERY COMPATIBLE WITH MODERN HYBRID CIRCUITRY. DURING PHASE I, WE WILL INVESTIGATE THE SELECTION OF A MEMORY DEVICE FOR THE SENSOR, CONDUCT RESEARCH ON TECHNIQUES TO MAKE THE SENSOR SENSITIVE TO A WIDE RANGE OF NEUTRON ENERGIES, AND COMPLETE THE CONCEPTUAL DESIGN OF THE FINAL DOSIMETER. THE RESULTING DEVICE SHOULD HAVE WIDE APPLICABILITY, GOOD USER ACCEPTANCE, AND BE A MAJOR ADVANCE IN THE STATE-OF-THE-ART OF PERSONNEL DOSIMETRY.