A SOFT X-RAY SOURCE WITH FOCUSING OPTICS FOR SPECTROSCOPY

THE OBJECTIVE OF THE PROPOSED RESEARCH PROGRAM IS TO INVESTIGATE THE USE OF COLLIMATING OPTICS WITH A TRANSITION-RADIATION SOURCE TO PRODUCE A LOW COST, LABORATORY SCALE, INTENSE, FOCUSED, SOFT X RAY SOURCE FOR SPECTROSCOPY. AS HAS BEEN SEEN FROM THE RAPID RISE IN THE USE OF SYNCHROTRON RADIATION, BRIGHT, RELATIVELY INEXPENSIVEX-RAY SOURCES ARE NEEDED FOR MATERIALS STUDIES AND OTHER SCIENTIFIC AND MEDICAL RESEARCH. WE PROPOSE TO CONSTRUCT AN X-RAY SYSTEM CONSISTING OF A TRANSITION RADIATOR AND COLLIMATING OPTICS WHICH WILL PERMIT THE ENTIRE RADIATION CONE TO BE FOCUSED TO A 1 - 2 MM(2) SPOT. FLEXIBLE CAPILLARY TUBES WILL PERMIT THE DIRECTION OF THE X RAYS TO BE CHANGED. PHASE I RESEARCH WILL BE USED TO TEST THE OPTICS AND THE FEASIBILITY OF THE SOURCE FOR SPECTROSCOPY. A COMPUTER-DRIVEN RAY-TRACING PROGRAM HAS BEEN DEVELOPED TO OPTIMIZE THE DESIGN OF THE X-RAY OPTICS. PRELIMINARY EXPERIMENTS AT ADELPHI HAVE SHOWN THAT X RAYS IN THE 1 - 3 KEV SPECTRA RANGE CAN BE FOCUSED TO A 2 MM DIAMETER SPOT AT A DISTANCE OF 1.35 M FROM THE SOURCE. THE PRINCIPAL INVESTIGATOR AND HIS COLLEAGUES WERE THE FIRST TO OBSERVE SOFT X-RAYS FROM TRANSITION RADIATORS AND SHOW FOCUSING OF THE RADIATION AT LARGE DISTANCES FROM THE RADIATOR.