Microchannel plate efficiencies for medium energy helium and carbon recoils in pulsed beam time-of-flight applications

Efficiencies of a microchannel plate detector for medium energy helium and carbon recoils were determined using a recently developed pulsed beam time-of-flight technique for near surface analysis by medium energy ion scattering. This technique utilizes a pulsed beam of singly charged He-4 or C-12 ions with energies in the 60-140 keV range to provide enhanced energy resolution when compared to conventional Rutherford backscattering techniques using solid state detectors. The detection efficiency of the microchannel plate detector was found to range between 54% and 60% for helium recoils and between 48% and 52% for carbon recoils over the energy range examined.