Fragmentation of N_2, O_2, and CO in electron capture collisions of ^3He^{2+} at energies below 1 kev/amu T.Kaneyasu, K.Ishii, M. Ehrich^a, M. Yoshino^b, and K. Okuno Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan ^aFakultaet fuer Physik, Universitaet Bielfeld, Postfach 100131, D-33501 Bielfeld, Germany ^bShibaura Institute of Technology, 307 Fukasaku, Ohmiya-shi, Saitama 330, Japan We have newly developed a double-coincidence time-of-flight (TOF) instrument to investigate the fragmentation in multiply charged ions with molecules collisions. Electron capture processes of ^3He^{2+} with N_2, O_2, and CO at energies below 1 keV/amu have been revealed by a new technique of three particle coincidence detection.