A NOVEL, COMPACT DC PARTICLE ACCELERATOR FOR DEEP SHAFT GEOPHYSICAL STRATA LOGGING

INTENSE X-RAY SOURCES HAVE BEEN USED IN GEOPHYSICAL RESEARCH PODS TO DETERMINE STRATA FORMATION DENSITY, LITHOLOGY, AND POROSITY. THE SCATTERING OF -RAYS FROM (137)CS OR (60)CO SOURCES WITH DECAY ACTIVITIES OF UP TO SEVERAL CI HAVE BEEN USED EXTENSIVELY IN BOREHOLE LOGGING. A NON-RADIOACTIVE PHOTON SOURCE IS HIGHLY DESIRABLE SINCE IT REDUCES THE RADIOLOGICAL HANDLING RISK AND THE RISK OF DOWN HOLE LOSS. NORTH STAR RESEARCH HAS CONCEIVED A NOVEL COMPACT ELECTROSTATIC ACCELERATOR THAT IS CAPABLE OF APPROACHING 1 MV/CM IN HIGH VOLTAGE GENERATOR DIAMETER THEREBY REDUCING THE SIZE AND MASS OF THE SYSTEM INSERTED INTO THE WELL SITE. PRELIMINARY EXPERIMENTS HAVE DEMONSTRATED THE UTILITY OF THIS ELECTRON ACCELERATOR IN LARGER SIZES. THIS 'NESTED HIGH VOLTAGE GENERATOR' WILL BE USEFUL FOR BOTH LOW ENERGY (< 300 KEV) , ELEMENTAL COMPOSITION AND HIGH ENERGY (300 KEV - 1 MEV) -RAY COMPTON SCATTERING MEASUREMENTS OF DENSITY. THE NESTED HIGH VOLTAGE GENERATOR APPROACH IS GENERATES A CONTINUOUS X-RAY STREAM WHICH SIMPLIFIES DETECTOR CALIBRATION WHEN COMPARED TO PULSED ACCELERATORS. THIS SOURCE WILL FACILITATE HIGHER RESOLUTION MEASUREMENTS OF THESTRATA STRUCTURE.