1988 Fiscal Year Final Research Report Summary
Rotational-State Resolved Study of Ion-Molecule Reactions at Ultralow Temperatures
| Project/Area Number |
62540283
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
物理学一般
|
|---|
| Research Institution | Tokyo Metropolitan University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Nobuo Tokyo Metropolitan University, 理学部, 助教授 (30087100)
|
|---|
| Project Period (FY) |
1987 – 1988
|
| Keywords | Injected-ion drift tube mass spectrometer / low temperature / helium cluster ions / 魔法数 |
|---|
| Research Abstract |
Drift tube of an injected-ion drift tube mass spectrometer was cooled with liquid helium for studing ion-molecule reactions at very low temperatures. By injecting ions X^+ (X=He, Ne, Ar, Kr) into the drift tube filled with helium gas of the pressure ranging from 0.01 to 0.06 Torr at the temperature of about 4.5 K, helium cluster ions (XHE_n)^+ were observed with the largest size of n=14.
Generally, the binding energy of a cluster decreases with increasing size. Therefore, when the drift field strength, the effective temperature of the drifting ions, in the drift tube is high, only the clusters having a larger binding energy than the effective temperature of the drifting ions may be detected. We measured a number of mass spectra by varing the electric field strength and determined the disappearance drift field strength of the cluster (XHe_n)^+. By this means, we were able to obtain an information about the stability of the clusters and determined the magic numbers. For the case X=He, the magic numbers n=1, 2, 9, 13 were observed. On the other hand, the differnt ones were observed for Ne and Ar.
|
Research Products
(2 results)
