X-rays from Coalescing Atoms.

The discovery and investigation of X-ray continua has provided a new tool for studying the detailed electronic processes that occur when atoms collide. In the collisions considered here, the quasimolecular origin of the continuum radiation has been established. Therefore, as the atomic numbers of the projectiles and target atoms are increased one can simulate some of the properties of superheavy atoms. In particular, the peaked nature of the x-ray energy dependence of the anisotropy of K, L, and M MO radiation, as well as the peaked nature of the M MO spectra, will allow approximate spectroscopic studies of superheavy atoms. Special excitement attaches to the possibility of observing fundamental processes occurring under extremely high electric and magnetic fields. The recent successful development of a 1400-Mev U beam at the GSI (Gesellschaft für Schwerionenforschung) accelerator in Darmstadt, Germany, promises an imminent attack on these basic problems (63).