1990 Fiscal Year Final Research Report Summary
Contraction of Reflection TOF Mass Spectrometer for Very High Ions
| Project/Area Number |
01840020
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
構造化学
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| Research Institution | Mie University |
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Principal Investigator |
SHINOHARA Hisanori Mie University, Department of Chemistry for Materials, Associate Professor, 工学部, 助教授 (50132725)
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| Co-Investigator(Kenkyū-buntansha) |
WASHIDA Nobuaki National Institute for Environmental Studies, Division Director, 大気圏環境部, 部長 (70101045)
NISHI Nobuyuki Institute for Molecular Science, Associate Professor, 分子科学研究所, 助教授 (60013538)
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| Project Period (FY) |
1989 – 1990
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| Keywords | MPI / Very high mass ions / Reflectron / Time-of-flight / Molecular clusters / Post acceleration / Supersonic nozzle |
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| Research Abstract |
A reflectron time of flight mass spectrometer has been constructed in order to detect molecular or molecular cluster ions of very high masses. The time-of-flight system is divided by three parts : (1) Supersonic nozzle source ; (2) Laser-ionization region ; (3) Time of flight drift tube and ion det ector. Multiphoton ionization (MPI) has been used in order to obtained high mass resolution and high ionization efficiency.
Molecular cluster ions, such as benzene and ammonia clusters, are detected by MPI method using an ArF excimer laser. Benzene clusters as high as 60-mer are detected, which corresponds to mass number 4,800. The detection limit is governed by the multichannel plate detector used and not by the reflectron time of flight mass spectrometer. To actually detect higher masses a conversiondynode type ion detector is necessary. The mass spectral resolution is as high as 2,500 and typically 2,000. The mass resolution is limited by the pulse width of the excimer laser (10 ns). Higher mass resolution will be obtained by using an ionizing laser with shorter pulse width. The present MPI reflectron time-of-flight mass spectrometer system is the first rate in terms of the mass resolution and the ion detection limit in mass axis.
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