| Project/Area Number |
06640645
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Physical chemistry
|
|---|
| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
|---|
Principal Investigator |
KOUCHI Noriyuki Tokyo Inst.of Tech., Dept.of Chem., Associate Professor, 理学部・化学科, 助教授 (50161873)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KAMETA Kosei Tokyo Inst.of Tech., Dept.of Chem., Associate, 理学部・化学科, 助手 (90214551)
UKAI Masatoshi Tokyo Inst.of Tech., Dept.of Chem., Associate, 理学部・化学科, 助手 (80192508)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Project Status |
Completed (Fiscal Year 1995)
|
| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Keywords | coincidence / electron energy-loss spectroscopy / highly-excited molecules / optically-forbidden transition / electron collosions / hydrogen molecules / doubly-excited states / neutral dissociation / 電子衝突ダイナミックス |
|---|
| Research Abstract |
We have established a new experimental technique to substantiate the dynamics of highly-excited molecules produced by electron collisions. The technique is electron energy loss spectroscopy in coincidence with the detection of the photons from the fragment atoms produced through the neutal dissociation of the highly-excited molecules. This method has been applied to hydrogen (H_2), the simplest of molecules, and the electron-energy-loss spectra in coincidence with H (2p) formation have been measured. What we have accomplished is as follows.
1. The coincident electron-energy-loss spectra of H_2 have been measured in the energy-loss region of single-electron excited states. There is a large change in the shape of the spectra on going to the lower impact energy. Interestingly, this change is seen in the limited region of the evergy loss. We have concluded that the change is ascribed to the appearance of the forbidden states which are likely to dissociate into H(1s)+H(2p). The forbidden states involved have been identified and the dissociation mechanism has been clarified.
2. The coincident electron-energy-loss spectrum of H_2 has been measured in the energy-loss region of doubly excited states. Two broad peaks are seen in the spectrum which are ascribed to the doubly excited states. This is the first observation of the doubly excited states of H_2 in electron energy-loss spectra. One of two peaks is explained by the known optically allowed doubly excited states. On the other hand the other peak is ascribed to the forbidden doubly-excited states. The precursor doubly-excited states, however, are left unknown. Our investigation has been stimulating many theoreticians.
In conclusion the coincident electron-energy-loss spectroscopy has proved to be a useful tool to substantiate the dynamics of highly-excited molecules produced by electron collisions.
|
