Energy-Loss Dependence of the Ion-Induced Desorption Yield Measured with Ar10+ Ions at GSI-HHT

In heavy ion synchrotrons like SIS 18 high energetic ions can impact on the beam pipe and release gas molecules. This so called ”ion induced desorption” deteriorates the accelerator vacuum and, as a consequence, the beam life time and luminosity. Desorption yields η (released gas atoms or molecules per incident ion) of various materials have been studied at GSI since 2003. A scaling of the desorption yield with the electronic energy loss to the second power (dE/dx) was found first for 1.4 MeV/u Pb, Cr and C ions [1] and afterwards for U ions (15-100 MeV/u) impacting on stainless steel, copper and aluminium targets [2]. In the energy regime investigated nuclear stopping can be neglected. In 2005, we studied the (dE/dx) scaling of the desorption yield of argon on stainless steel (316LN, vacuum fired) at the same energies per nucleon as in [2]. The intension was to verify the observed scaling for a different projectile ion.