X rays from atomic systems of combinedZ≃130

The x-ray spectrum in the region from about 2 to 42 keV has been measured for 25-MeV iodine ions incident on thick and thin gold targets, 37.8-MeV gold ions incident on thick tin targets, and 23.9-MeV gold ions incident on thick gold targets. The spectra were obtained for several values of aluminum absorbers inserted between the target and detector. The broad band of x-ray emission lying in energy between about 6.5 and 9.5 keV observed by Mokler et al. is confirmed as is their suggestion that it arises from $M$ x rays from the quasiatom system of $Z\simeq 130$. A search for $L$ x rays from these systems was inconclusive.