SCILNTILLATION FIBER DETECTOR FOR IN-VIVO ENDOSCOPIC INTER- NAL DOSIMETRY

AN ALPHA/BETA RADIATION DETECTOR SUITABLE FOR USE IN THE INSTRUMENT CHANNEL OF A FIBEROPTIC ENDOSCOPE WILL BE WILL BE DEVELOPED TO PROVIDE IN-VIVO IN-SITU BIOASSAY MEASUREMENTS LEADING TO COMPUTER-ASSISTED ESTIMATES OF IN- TERNAL DOSE AND DISTRIBUTION IN THE RESPIRATORY AND GASTRO- INTESTINAL TRACTS. DURING PHASE I OF THE PROGRAM, ALPHA AND BETA PARTICLE SENSITIVE SCINTILLATING PLASTIC FIBERS WILL BE PULLED (1.0 TO 3.5 MM O.D.) AND FABRICATED TO COUPLE THEIR LIGHT-PIPED EMISSIONS TO A PHOTOMULTIPLIER DETECTOR. A VARIETY OF SCINTILLATOR FORMULATIONS AND DESIGNS WILL BE TESTED TO ASCERTAIN HOW DETECTION CHARAC- TERISTICS VARY WITH PHYSICAL PARAMETERS. ALPHA AND BETA PARTICLE SCINTILLATION SPECTRA WILL BE STUDIED USING A MICROCOMPUTER MULTI-CHANNEL ANALYZER TO ASSESS EFFICIENCY, RESOLUTION, AND MINIMUM DETECTABLE AMOUNTS (MDA). PRELIMIN-ARY DIAGNOSTIC PROCEDURES WILL BE DEVELOPED TO ASSIST IN THEDETERMINATION OF THE OVERALL UTILITY OF THE ANALYTIC METHOD FOR COMPUTERIZED INTERNAL DOSE ESTIMATES.