KβHypersatellite Observation in Magnesium

The $K$ x-ray spectrum of Mg produced by 30-MeV oxygen ions is observed to consist of four regions of $K$ x-ray excitations. These regions consist of the $K\alpha$ satellite lines, the $K\beta$ satellite lines, the $K\alpha$ hypersatellite lines, and the $K\beta$ hypersatellite lines. The last region is observed for the first time and corresponds to $1s\to 3p$ transitions in an atom consisting of double $K$-shell vacancies as well as multiple $L$-shell vacancies.