A beam of polarized ³He⁺ ions has been produced using
atomic beam method techniques. This method has the attraction of being capable of producing an ion beam with polarizations up to 100%. The polarization of ³He beams presently produced by optical pumping techniques is of the order of 5%. The apparatus is composed of three main sections, the atomic beam source consisting of a supersonic nozzle cooled to liquid helium temperatures to produce a low velocity atomic beam, the tapered hexapole magnet to spatially separate the particles in the two magnetic spin substates, and the electron bombardment ionizer to produce ³He⁺ ions from the neutral ³He atomic beam. The low velocity beam is required because the nuclear magnetic moment of ³He is of the order of 1000 times smaller than the electronic magnetic moment used to separate beams in conventional Stern-Gerlach magnets and to achieve a high ionization efficiency. The measured intensity of the beam produced by the atomic beam source cooled to liquid helium temperature was 1 x 10¹⁸ atoms/sr-sec, the most probable velocity was 310 m/sec, and the velocity full width at half maximum was 50 m/sec. The beam flux through the ionizer increases by a factor of 1.3 when the hexapole field is turned on, in good agreement with the theoretically expected increase. This increase corresponds to a polarization of 65% of the atomic beam. A 12nA³He⁺ ion beam was obtained corresponding to an ionization efficiency of approximately 0.15%. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/35046 |
| Date | January 1970 |
| Creators | Vyse, Robert Norman |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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