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

Relative production cross sections for beam ($Z_1$) and target ($Z_2$) $K$ vacancies in heavyion collisions are explained for situations where $Z_1\simeq Z_2$. Electron promotion creates a vacancy in the $2p\sigma$ molecular orbital. As the collision partners retreat, the vacancy has a probability $w(v_1, Z_1, Z_2)<~\frac{1}{2}$ 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.