|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1999 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1998 : ¥2,600,000 (Direct Cost : ¥2,600,000)
In collisions of highly charged ions with atom and molecules the most dominant processes are charge transfer processes in which highly charged ions capture an electron or many electrons into their excited state levels from targets. Many investigators have studied on electron capture processes of highly charge ions in collisions with atomic targets, however, details of the capture processes for molecular targets have been little investigated till now, because molecular explosion processes are too complicate.
In this project, we have developed a new double-coincidence time-of-flight (TOF) instrument for three particle coincident detection. The experimental technique is very powerful to resolve complex reaction mechanisms in collisions of multiply charged ions with molecules. Especially for diatomic molecules, all reaction processes can be resolved by this technique. Then, for collision systems of HeィイD12ィエD1+ and KrィイD18ィエD1+ with NィイD22ィエD2, OィイD22ィエD2, and CO targets, we have measured fragmentation of N2, C2 and CO in each electron capture processes and branching ratios for each reaction channel and kinetic energy release distribution for each fragmentation have been determined at some energies below 1keV/amu. Also, in the measurements of their collision energy dependence, we have found some new phenomena due to the post collision between projectile ions and target ions after collisions, where coincident ion pair peaks are splitting into two peaks and molecular ion peaks are shifting by getting momentum with decreasing of the collision energy. The observation of the post co9llision effects gives us important information to understand the collision dynamics.