K -Vacancy Sharing in Near-Symmetric Heavy-Ion Collisions

Relative production cross sections for beam (Z₁) and target (Z₂) K vacancies in heavyion collisions are explained for situations where Z₁Z₂. Electron promotion creates a vacancy in the 2pσ molecular orbital. As the collision partners retreat, the vacancy has a probability w(v₁, Z₁, Z₂)<~1/2 to be transferred to the $1s$ level of the higher-Z collision partner. With a charge-transfer theory of Demkov, a universal form for w is obtained, which is in excellent agreement with all available data for Ni, Br, and I beams over extended target and energy ranges.