Universal cross sections forK-shell ionization by heavy charged particles. II. Intermediate particle velocities

Relativistic Heavy-Ion-Atom Collisions

“…The theory of Basbas et al (1978; thin solid lines in Fig. 9) predicts that for these collisions, the reduced cross sections increase with Zt, because the polarization effects are more important than binding effects.…”

“…The nonlinear response of the amplitude for ionization to an increase of the perturbing charge is viewed as the effect of the distortion of the electronic wave functions (Basbas et al 1978). This distortion reduces the ionization cross -16 -sections at low ion velocities, but increases them at high velocities.…”

“…At low velocities, the electrons form diatomic molecular orbitals around the projectile and target nuclei, thereby becoming more tightly bound and more difficult to excite, so smaller ionization cross sections are seen (Basbas et al 1973;Anholt and Meyerhof 1977). At high ion velocities, the polarization of the electron clouds decreases the electron-perturbing-nucleus distance, thereby increasing the strength of the perturbing potential, leading to higher ionization cross sections (Basbas et al 1971a(Basbas et al , 1971b(Basbas et al , 1978. These distortion effects affect high-Z projectile ionization and target K-vacancy production by relativistic projectiles.…”

“…excitation occurs at small impact parameters where the strong perturbing potential can significantly distort the inner-shell wave functions, giving a nonlinear dependence of the amplitude on Zx (Basbas et al 1973(Basbas et al , 1978.…”

Multiple ionization and capture in relativistic heavy-ion atom collisions

“…and final. electron states.. Also, at ion velocities generally used, wave-function distortion effects such as binding and polarization are present [10]. These effects, themselves the subject of much investigation [11 ], tend to obscure possible electron correlation effects in multiple ionization.…”