This paper deals with the explanation of what seemed, under the circumstances, a rather surprising activity of about 30 minutes induced in crystals of potassium iodide when bombarded at 40 Mev in the McGill cyclotron. It is shown that the activity is, in reality, complex and arises from (1) C134 (32 min) formed from the K nuclei and (2) I128 127 (25 min) formed by neutron capture in I127. This is the first example of a strong activity so formed in the McGill cyclotron by capture of the numerous neutrons known to be released in all targets at high energies. In the fall of 1950, D. E. Tilley, J. D. Keys and W. S. Boyle, all members of the McGill Radiation Laboratory, bombarded, in the McGill cyclotron, crystals of iodine and iodine salts with protons of various energies. In newly bombarded crystals (i.e. before any separation of the elements was attempted) they noticed, among other things, an activity of half-life approximately 30 minutes. This particular activity appeared most markedly when the bombarding protons had energies from 30 to 50 Mev. The purpose of the work reported here is to identify this 30 minute activity. Iodine, atomic number 53, has only one stable isotope, I127. Some of the present published knowledge(l, 2, 3, 4, 5, 6, 7, 8) about the active iodine isotopes, and about the isotopes of xenon (atomic number 54) and other nearby elements, is summarized in Figure 1. The chart shows the relative abundances of the stable isotopes [...]
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.124012 |
| Date | January 1952 |
| Creators | Dewdney, John Wells. |
| Contributors | Foster, J. (Supervisor) |
| 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: 000482181, Theses scanned by McGill Library. |
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