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Timothy J. Gay Publications

1988

Articles 1 - 2 of 2

Full-Text Articles in Physics

Dynamics Of Antimatter-Atom Collisions, R. E. Olson, Timothy J. Gay Jul 1988

Dynamics Of Antimatter-Atom Collisions, R. E. Olson, Timothy J. Gay

Timothy J. Gay Publications

Classical-trajectory Monte Carlo calculations have been used to study ionizing collisions between charged particles (p, , ℯ+, ℯ-) and He atoms at an incident velocity of 2.83 a.u. While differences in the total single-ionization cross sections for these projectiles are small, our calculations reveal large effects at all angles in the ionized electron spectra, and provide qualitative evidence for a Barkas effect in p and collisions. Experimental data agree well with our fully classical calculations, including cross sections involving ejected electrons of long wavelength.


Projectile-Charge Dependence Of Ejected-Electron Spectra, V. D. Irby, Timothy J. Gay, J. Wm. Edwards, E. B. Hale, M. L. Mckenzie, R. E. Olson May 1988

Projectile-Charge Dependence Of Ejected-Electron Spectra, V. D. Irby, Timothy J. Gay, J. Wm. Edwards, E. B. Hale, M. L. Mckenzie, R. E. Olson

Timothy J. Gay Publications

We have studied H++He and 3He+++He ionizing collisions at intermediate energies (60 to 120 keV/amu) and have observed a significant shift in the velocity position of the maxima in forward-ejected electron spectra when changing projectiles from protons to α particles. In ionizing collisions, a large portion of the ejected electrons are stranded near the transitory equiforce, or saddle point, position between the target ion and receding projectile. The shift in the electron spectra maxima to smaller velocities, due to changing projectiles from protons to α particles, is consistent with the shift in the saddle-point velocity …