| Autor: |
Paul W. Geno, Ronald D. Macfarlane |
| Rok vydání: |
1989 |
| Předmět: |
|
| Zdroj: |
International Journal of Mass Spectrometry and Ion Processes. 92:195-210 |
| ISSN: |
0168-1176 |
| DOI: |
10.1016/0168-1176(89)83028-9 |
| Popis: |
In this study, the question of the previously reported existence of a velocity threshold at 18 000 m s−1 for secondary electron emission induced by ion impact on a surface is examined. This is of concern for the use of electron multipliers for the detection of high mass molecular ions. A 252Cf plasma desorption mass spectrometer was used to determine the secondary electron emission coefficients for molecular ions from three small peptides striking the surface of a microchannel plate electron multiplier detector. Secondary electron coefficients were found to vary exponentially with velocity between 15 000 and 32 000 m s−1 and linearly with mass from m/z 86 to m/z 1059. An expression for the secondary electron coefficient as a function of velocity and mass was derived from the data. It was found to correlate with results previously obtained for insulin using different acceleration voltages. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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