General aspects of the excitation of matter with heavy-ion beams are discussed. Lasers in the wavelength region between 1 and 3 urn in rare-gas mixtures pumped with 1.9-GeV xenon, 100-MeV sulphur, 3.6-MeV argon, and 3.3-MeV helium ions are described as examples for lasers pumped by heavy-ion beams. The beam power ranges from a few watts (dc) to about 1 MW during short pulses of about 1-ns length. Optical gain can be measured with an intracavity method. Data on the shape of the volume excited by a 100-MeV 32 S beam are shown. An experimental setup for time-resolved optical spectroscopy in a wide wavelength region between a few nanometers and about 700 nm is described. Emission spectra of rare gases excited by heavy-ion beams are discussed and optical gain on ion lines and excimer bands is estimated for different target and beam parameters. Collisional processes in the target gas were studied by time-resolved optical spectroscopy. Population densities of selected 3p levels in Ne i, n, and rv and rate constants for collisional depopulation of excited levels were determined. Experiments planned at the heavy-ion synchrotron SIS at Gesellschaft fiir Schwerionenforschung in Darmstadt are discussed.

Optical gain on the 476.5 nm Ar II 4p-4s ion laser transition has been observed in argon-gas excited by 2.5 ns pulses of 90 MeV 32S ions with a repetition rate of 4883 Hz. The energy per pulse was 23 gJ. The projectiles were stopped in the target at pressures between 5 and 20 kPa. Gain was determined from a measured transient increase of the intensity of a 476.5 nm probe laser beam sent along the ion beam axis and back reflected by an aluminum foil. The maximum gain observed was (0.4_+0.1) x 10 3 at a target-gas pressure of 5 kPa. Control experiments using krypton as target-gas were performed and yielded a null result. The optical gain observed in argon is consistent with the result from an analysis of spectroscopic studies of rare-gas targets excited by heavy ion beams. PACS" 42.55.Hq; 52.20.Hv