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Calorimetric low temperature detectors (CLTD's) for heavy-ion detection have been combined with the LOHENGRIN recoil separator at the ILL Grenoble for the determination of nuclear charge distributions of fission fragments produced by thermal neutron-induced fission of $$^{235}$$ U. The LOHENGRIN spectrometer separates fission fragments according to their mass-to-ionic-charge ratio and their kinetic energy, but has no selectivity with respect to nuclear charges Z. For the separation of the nuclear charges, one can exploit the nuclear charge-dependent energy loss of the fragments passing through an energy degrader foil (absorber method). This separation requires detector systems with high energy resolution and negligible pulse height defect, as well as degrader foils which are optimized with respect to thickness, homogeneity, and energy loss straggling. In the present, contribution results of test measurements at the Maier Leibnitz tandem accelerator facility in Munich with $$^{109}$$ Ag and $$^{127}$$ I beams with the aim to determine the most suitable degrader material, as well as measurements at the Institut Laue-Langevin will be presented. These include a systematic study of the quality of Z-separation of fission fragments in the mass range $$82\le A \le 132$$ and a systematic measurement of $$^{92}$$ Rb fission yields, as well as investigations of fission yields toward the symmetry region. [ABSTRACT FROM AUTHOR]

Calorimetric low temperature detectors (CLTD's) have been included in a B-ToF setup, that has already been used several times to perform energy loss measurements at the accelerator laboratory of the University of Jyväskylä. The new experimental setup enabled a precise determination of stopping power data for 0.05-1 MeV/u $$^{131}$$ Xe ions in carbon, nickel and gold. The results are presented and compared to data from literature and theoretical predictions. As a by-product, due to the excellent energy resolution of CLTD's for heavy ions at low energies, an observation of channeling effects in very thin polycrystalline targets and a determination of the channeling energy loss for 0.1-0.5 MeV/u $$^{131}$$ Xe-ions in Ni- and Au-absorbers was possible. [ABSTRACT FROM AUTHOR]

The precise determination of the transition energy of the Lyman- $$\alpha $$ 1 line in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. We report the determination of the Lyman- $$\alpha $$ 1 transition energy of gold ions (Au $$^{78+}$$ ) with microcalorimeters at the experimental storage ring at GSI. X-rays produced by the interaction of 125 MeV/u Au $$^{79+}$$ ions with an internal argon gas-jet target were detected. The detector array consisted of 14 pixels with silicon thermistors and Sn absorbers, for which an energy resolution of 50 eV for an X-ray energy of 59.5 keV was obtained in the laboratory. The Lyman- $$\alpha $$ 1 transition energy was determined for each pixel in the laboratory frame, then transformed into the emitter frame and averaged. A Dy-159 source was used for energy calibration. The absolute positions of the detector pixels, which are needed for an accurate correction of the Doppler shift, were determined by topographic measurements and by scanning a collimated Am-241 source across the cryostat window. The energy of the Lyman- $$\alpha $$ 1 line in the emitter frame is $$E(Ly-\alpha 1,Au^{+78})=(71563 \pm 4_{stat} \pm 7_{syst})$$ eV, in good agreement with theoretical predictions. The systematic error is dominated by the uncertainty in the position of the cryostat relative to the interaction region of beam and target. [ABSTRACT FROM AUTHOR]