Residual activity induced by U ions of energy 500 MeV/u in a Cu target *

Measurements of the residual activity induced by U ions of different energies in Cu and stainless steel targets have been taken at GSI Darmstadt. In this paper we pre-sent the results of measured residual activity induced by U ions with E = 500 MeV/u in a Cu target and discuss possible “hands-on” maintenance problems in the tunnel of the SIS100 synchrotron of FAIR. The cylindrical Cu target was assembled of discs of the diameter of 50 mm and different thickness. The U beam spot was less than 11 mm in diameter. The total thickness of the Cu target was twice the range of the U ions, thus the beam stopped completely inside the target. Analyses of the gamma-spectra of the activated discs allowed to identify the radioisotope concentration in each disc and to plot the depth profile for each isotope. The following set of radioisotopes was detected in the discs: a) produced by fragmentation of the target and projec-tile nuclei: