STATE-SELECTIVE DIFFERENTIAL CROSS SECTION MEASUREMENTS FOR ONE-ELECTRON CAPTURE PROCESSES AT 10 eV REGION Yoh Itoh* Physics laboratory, Josai University, Saitama 350-0295, Japan A crossed-beam apparatus connected to a small Electron-Beam-Ion-Source is described. The kinetic energy of O^+ ions produced in one-electron capture process in O^2+ + He collisions were measured at E_cm = 10 eV, from 0 to 5 degree in the laboratory frame. Only a single peak which corresponds to the reaction, O^2+(^3P) + He ---> O^+(^2P) + He+ + 5.6 eV, was observed in the energy spectra.