X-ray Production in Low Velocity Heavy Ion-Atom Collisions

Abstract

<p>Two aspects of x-ray production have been studied in the collisions of slow heavy ions with heavy atoms. One part of this study deals with the continuum x-rays produced by the collision of ion beams with gold target atoms while the other part deals with the double K-vacancy production in collisions of 80 MeV iodine beams with atoms of atomic numbers near that of iodine.</p> <p>Beams of four different ions ranging in atomic number from Z=6 (carbon) to Z=35 (bromine) and having the same velocity (v ∼ or = 0.04 c) bombarded gold atoms to produce very similar radiation continua extending from 20 keV photon energy. The observed radiation continua cannot be explained, in their entirety, as molecular orbital x-rays.</p> <p>The double K-vacancy production was produced in the bombardment by an iodine beam of seven thin targets ranging from silver to lanthanum. The double vacancies were detected by observing two K x-rays emitted simultaneously using a coincidence technique with solid state detectors. The energy differences of the K x-rays emitted have been determined as well as the nature of the sharing of vacancies between target and projectile atoms. Models for double K-vacancy production considered include the molecular orbital multiple collision approach and the binary encounter formalism of direct Coulomb excitation. Also a calculation of the double to single K-vacancy ratios was made using a double L-vacancy multiple collision MO mechanism in which the double to single L-vacancy cross section ratio was treated as a free parameter.</p>