1990 Fiscal Year Final Research Report Summary
Dissociation Dynamics of Doubly and Triply Charged Simple Gaseous Molecules Studied by Double and Triple Coincidence Method
| Project/Area Number |
01540383
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
物理化学一般
|
|---|
| Research Institution | Osaka City University |
|---|
Principal Investigator |
MASUOKA Toshio Osaka City University, Faculty of Engineering, Lecturer, 工学部, 講師 (80047208)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOYANO Inosuke Himeji Institute of Technology, Faculty of Science, Professor, 理学部, 教授 (80016089)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Keywords | Double ionization / Dissociative photoionization / Ionic fragment / Anisotropy of fragmentation / Kinetic energy distribution / Triple coincidence / Synchrotron radiation |
|---|
| Research Abstract |
1. The triple coincidence PEPIPICO (photo electron-photoion-photoion) technique has been developed at the UVSOR facility of IMS (BL3A2) in Okazaki to study the dynamics of fragmentations of a di-or tri-cation into two charged and one neutral particle. Two dimensional expression of the triple coincidence spectra in real time was made possible by use of a personal computer and a video RAM. The dissociative double and triple photoionization of OCS was studied by this method at the excitation energy of 80eV. New information on the charge separation was obtained for the dissociation channels C^++ O^++S of OCS^<2+> and OC^++S^<2+> of OCS^<3+>.
2. The angular distribution of photo dissociation products is closely related to the symmetry of the transition processes involved and the molecular dissociation dynamics. We have observed angular distribution of fragment ions produced in the direct (not via Auger decay) double photoionization of OCS, CH_3F, and NO by use of synchrotron radiation and the photoion-photoion coincidence (PIPICO) method. The TOF mass spectrometer could be rotated throuqh 90^ﾟ around the photon beam in order to measure characteristic profiles of the PIPICO spectra. The present study shows that the anisotropy, observed here for the first time in the case of direct two-electron-ejection processes, can be understood in terms of symmetry-characterized-dissociation of the doubly charged parent ions.
3. The single, double, and triple photoionization cross sections of OCS and the ionic fragmentations of OCS^+, OCS^<2+>, and OCS^<3+> have been determined separately in the region 36-100eV by use of a TOF mass spectrometer and the PIPICO method together with synchrotron radiation from the UVSOR
4. Kinetic energy distributions of the fragment ions produced from OCS^<2+> and NO^<2+> were also determined.
|
