SOLID STATE RADIAC

THIS INNOVATION PROPOSES FEASIBILITY STUDIES LEADING TO THE DEVELOPMENT OF A FULLY PORTABLE AND SELF-CONTAINED UNDERWATER RADIAC INSTRUMENT CAPABLE OF CONCURRENT AND SEPARATE DETECTION, ANALYSIS, MEASUREMENT AND DISPLAY OF BOTH GAMMA AND NEUTRON RADIATION. THE UNIT WILL BE DESIGNED AS A SMALL, LIGHTWEIGHT, RUGGED, ONE-DIVER INSTRUMENT EMPLOYING SCINTILLATOR CRYSTALS TO CONVERT NUCLEAR RADIATION INTO UV/VISIBLE LIGHT PULSES. THE LIGHT PULSES WILL THEN BE ANALYZED AND MEASURED VIA A NEWLY DEVELOPED AND ADVANCED SOLID STATE AVALANCHE PHOTODETECTOR AND ANCILLIARY ELECTRONICS. TWO ELEMENTS ARE CONSIDERED KEY TO THE BASIC DESIGN CONCEPT. FIRST, IS THE USE OF TWO DIFFERENT SCINTILLATOR MATERIALS - SODIUM IODIDE, WHICH WILL SERVE AS THE PRIMARY, HIGH SENSITIVITY GAMMA DETECTOR AND ALOS AS AN ANTICOINCIDENCE SHIELD, AND GADOLINIUM ORTHOSILICATE FOR ITS THERMAL NEUTRON SENSITIVITY. THE SECOND KEY ELEMENT IS THE USE OF A NEWLY DEVELOPED, LARGE AREA (TO CENTIMETERS IN DIAMETER), HIGH GAIN, SILICON AVALANCHE PHOTODIODE (APD) AS THE LIGHT DETECTOR. THE MORE RUGGED SOLID STATE APD HAS A SMALLER VOLUME, BUT THE SAME SENSITIVE DETECTION AREA AS THE PHOTOMULTIPLIER TUBE NORMALLY USED FOR SCINTILLATOR APPLICATIONS.