A novel high precision slit system

A new high precision slit system has been developed for the nano beam facil ity SNAKE (Supraleitendes Nanoskop fur Angewandte Kernphysikalische Experim ente) which is under construction at the Munich tandem accelerator. Cylindr ically strained germanium wafers with a bending radius of 50 mm are used as optimized slit edges. High resolution and angle resolved energy distributi ons of the transmitted protons were measured by means of a Q3D magnetic spe ctrograph at incident energies of 20 MeV. The measurements revealed the exp ected strong correlation between small angle scattering and energy loss pro cesses at the slits. Within SNAKE's angular acceptance the ratio of particl es suffering energy loss by interacting with the slit and particles not int eracting with the slit is less than 0.6% even for aperture widths of 2 mu m (C) 1999 Elsevier Science B.V. All rights reserved.