OPTICAL DETECTION OF CHARGED PARTICLE TRACKS FOR BEAM MONITORING

THIS STUDY INVOLVES THE DEVELOPMENT OF A METHOD FOR OPTICALLY IMAGING INDIVIDUAL CHARGED PARTICLE TRACKS WITH GOOD THREE-DIMENSIONAL SPATIAL RESOLUTION. A CHARGED PARTICLE PASSING THROUGH A GAS WILL IONIZE THE GAS AND LEAVE A TRACK OF FREE ELECTRONS THAT WILL RAPIDLY BECOME THERMAL. WHEN SUITABLE HIGH VOLTAGE RADIO FREQUENCY FIELDS ARE APPLIED, THE THERMAL ELECTRONS GAIN ENERGY AND EXCITE PHOTON EMISSION FROM THE GAS. CALCULATIONS SUGGEST THAT EACH THERMAL ELECTRON CAN BE MADE TO INDUCE MORE THAN 10(6) PHOTONS. LIGHT DETECTION WITH A PAIR OF EXTERNAL SOLID STATE CAMERAS WILL PERMIT THREE-DIMENSIONAL RECORDINGS OF THE ELECTRON'S LOCATION FOR OPTICAL GAINS GREATER THAN 10(5). PHASE I WILL ATTEMPT TO PROVE THAT A SINGLE CHARGED PARTICLE TRACK PRODUCED BY A PARTICLE CAN BE IMAGED ON HIGH SPEED PHOTOGRAPHIC FILM TO DETERMINE ITS POSITION, DIRECTION, AND LINEAR ENERGY TRANSFER (LET). PHASE II WILL DEMONSTRATE THAT MANY TRACKS FROM A DETECTOR PLACED IN A CHARGED PARTICLE BEAM CAN BE IMAGED IN ONE FRAME USING AN INTENSIFIED SOLID STATE CAMERA, AND THAT THE DATA CAN BE DIGITIZED AND STORED IN A COMPUTER TO CALCULATE BEAM INTENSITY, POSITION, EMITTANCE, AND APPROXIMATE ENERGY.