Dielectric Measurements on SBN:Ce

LASER SPECTROSCOPY WITH A COOLER RING AT THE ESR (GSI) AND THE TSR (MPI HEIDELBERG)

At the TSR cooler ring at Heidelberg, laser studies were carried out using singly charged lithium and beryllium ions. Laser spectroscopy of relativistic lithium ions (v=0.04c) yielded signals with a narrow linewidth, suitable for an experimental test of special relativity. A dramatic reduction of the beam temperature, as defined by the longitudinal velocity spread, was achieved via laser cooling in both cases. At the ion energies available at ESR it will become possible to prepare and store bare ions up to U92+. Electron cooling was succesfully demonstrated for hydrogen-like Bi82+ ions, where a laser experiment is scheduled to study the ground-state hyperfine splitting.

OH/OD-IR absorption bands in SrxBa1−xNb2O6

Single crystals of Sr x Ba 1−x Nb 2 O 6 (SBN) with congruent composition (x = 0.61) and Sr 0.61 Ba 0.39 Nb 2 O 6 crystals doped with various concentrations of cerium are grown with the Czochralski method. A subsequent doping of the crystals with protons and deuterons is performed either by hydrothermal high temperature treatment or by field supported hydrogen diffusion at elevated temperatures in humid atmosphere. The presence of the protons is revealed by the infrared absorption of the OH stretching vibration. This broad OH absorption band is essentially the same for Sr 0.61 Ba 0.39 Nb 2 O 6 and Sr 0.61 Ba 0.39 Nb 2 O 6 :Ce (0.025 wt% CeO 2 ). It shows a polarization dependence with respec…