Rotational-State Resolved Study of Ion-Molecule Reactions at Ultralow Temperatures
| Project/Area Number |
62540283
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理学一般
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Nobuo Tokyo Metropolitan University, 理学部, 助教授 (30087100)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1987: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Injected-ion drift tube mass spectrometer / low temperature / helium cluster ions / 魔法数 / 極低温イオン・分子反応 |
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| 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.
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Report
(3 results)
Research Products
(3 results)
