A PULSED X-RAY SOURCE USING K-EDGE TRANSITION RADIATION

THE OBJECTIVE OF THE PROPOSED RESEARCH PROGRAM IS TO INVESTIGATE THE USE OF A NOVEL TRANSITION-RADIATION SOURCE TO PRODUCE A LOW-COST, LABORATORY-SCALE, INTENSE, PULSED X-RAY SOURCE. BY DESIGNING TRANSITION RADIATORS TO EMIT X RAYS AT THE FOIL MATERIAL K-SHELL PHOTOABSORPTION EDGE, THE X-RAY SPECTRUM IS NARROWED. THE SOURCE IS THUS QUASIMONOCHROMATIC (20 TO 50% BANDWIDTH), DIRECTIONAL, INTENSE AND USES AN ELECTRON BEAM WHOSE ENERGY IS CONSIDERABLY LOWER THAN THAT NEEDED FOR SYNCHROTRON SOURCES. BY USING A PULSED ELECTRON SOURCE, FOIL HEATING IS MINIMIZED AND HIGH-PEAK CURRENTS CAN BE OBTAINED. THE RADIATION PRODUCED CAN BE IN THE WARM (5 TO 15 KEV) AND HARD (>15 KEV) X-RAY REGIONS OF THE SPECTRUM DEPENDING UPON THE FOIL MATERIAL USED, THE FOIL THICKNESS, AND THE ELECTRON-BEAM ENERGY. PHASE I RESEARCH WILL BE TO DESIGN RADIATORS, DETERMINE THEIR THEORETICAL X-RAY FLUX AND DETERMINE EXPERIMENTALLY THE TOTAL OUTPUT POWER USING THE ROSS FILTER TECHNIQUE. BREMSSTRAHLUNG CONTAMINATION WILL BE CALCULATED AND MEASURED.