Reflectivity enhancement of large m-Qc supermirror by ion polishing

The reflectivity of Ni/Ti supermirror with 3Qc has been enhanced by using ion-polishing technique in combination with an ion-beam sputtering system. The dependencies of ion-polishing time, ion acceleration energy and incidence angle on the interface roughness were firstly studied to optimize the conditions of Ar+ ion polishing by using X-ray and neutron reflectometry. Based on the optimal ion-polishing condition, Ni/Ti supermirrors with 3Qc were fabricated and characterized. The reflectivity has been increased, and it reached 87% at the critical angle of total reflection.