Enhancement of reflectivity of multilayer neutron mirrors by ion polishing: optimization of the ion beam parameters

The reflectivity of multilayer mirrors depend on the interface roughness cr eated during deposition of the layers. In order to smoothen the interfaces, we have investigated the influence of argon ion bombardment on the interfa ce roughness of a Ni/Ti multilayer deposited by ion beam sputtering. The de pendencies of ion polishing time, ion acceleration energy and incident angl e on the interface roughness were studied to optimize the conditions of Ar ion polishing. It was observed that the reflectivities and the evaluated i nterface roughness of multilayers are obviously improved by using ion polis hing. (C) 1999 Elsevier Science Ltd. All rights reserved.