An experimental set-up consisting of an electron-impact induced ionization chamber, a quadrupole mass filter and an ion detector has been constructed. The operating characteristics of the quadrupole mass filter system have been examined and compared to the theoretical predictions. With a moderate mass resolution of 30, an absolute ion transmission efficiency of about 10% has been obtained. This system has been used to investigate the ionization efficiency of noble gases. Charged species up to He$ sp{2+}$, Ne$ sp{4+}$, Ar$ sp{6+}$, Kr$ sp{5+}$ and Xe$ sp{7+}$ have been studied. The behavior of the ionization efficiency curve near threshold is analyzed using a power law fitting approach. For the first and second degree ionization processes, the fitting power law coefficients k are found to be close to the charge number of the ions produced, in agreement with the theoretical predictions. The extracted ionization potentials also agree with the accepted values. For the third and higher degree of ionization, the k-values are generally much lower than the theoretical predictions. However, the extracted ionization potentials are still consistent with the accepted values.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.59907 |
| Date | January 1991 |
| Creators | Wang, Gang, 1958 Nov. 28- |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001237016, proquestno: AAIMM67457, Theses scanned by UMI/ProQuest. |
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