High energy single ion hit system combined with heavy ion microbeam apparatus

A high-energy single ion hit system was combined with the JAERI heavy ion microbeam apparatus to study single event upset phenomena of semiconductor devices in space environment with a spatial resolution of 1 mu m The single ion hit system consists of a single ion detector and a fast beam switch which controls the timing and the number of ions hitting the target. The detection efficiency for a single ion was evaluated at 100% for 15 MeV Ni ions by using a set of annular type microchannel plates. The switching time of 720 ns was compared with the mean time interval between two successive ions passing through the beam switch, and the probability that multiple hits occur within the time interval was calculated. An extremely low ion beam current of less than 1 fA also can be accurately controlled by the single ion hit system.