New results on the absolute ion detection efficiencies of a microchannel plate

Absolute single-particle detection efficiencies and pulse height distributions of a cascaded microchannel plate (MCP) detector are reported for the ions , , , and in the impact energy range 0 - 4.75 keV. The detection efficiencies have been obtained using the photoelectron - photoion coincidence (PEPICO) technique which allows the determination of detection efficiencies without knowledge of the absolute ionization rate. The mean gain is found to increase with increasing ion impact energy and decreasing ion mass. Depending on the ion mass, the absolute detection efficiencies saturate above 2.5 keV and reach about 63%.