Determination of electronic stopping powers of 0.05-1Â MeV/u 131Xe ions in C-, Ni- and Au-absorbers with calorimetric low temperature detectors

A new experimental system for precise determination of electronic stopping powers of heavy ions has been set up at the accelerator laboratory of the University of Jyväskylä. The new setup, combining an established B-ToF system and an array of calorimetric low temperature detectors (CLTDs), has been used for the determination of electronic stopping powers of 0.05-1 MeV/u 131Xe ions in carbon, nickel and gold. Thereby advantage of the improved linearity and energy resolution of CLTDs as compared to the previously used ionization detector was taken to reduce energy calibration errors and to increase sensitivity for the energy loss determination, in particular at very low energies. The total uncertainties of 3-4% for C- and Ni-targets, and 5-7% for Au-targets, respectively, are dominated by the target properties, i.e. thickness determination and inhomogeneities. The results are compared to data from literature and to predictions of different theoretical computer codes. In the high energy part of the examined energy range the results are in good agreement with previously published data, while new stopping power data for very heavy ions in different Z2-materials have been obtained at lower energies. Moreover, unexpectedly strong channeling effects for the transmission of the 131Xe ions in thin, partly polycrystalline nickel and gold target foils have been observed and investigated.