dc.contributor.author | Pohjalainen, Ilkka | |
dc.date.accessioned | 2018-06-14T06:48:24Z | |
dc.date.available | 2018-06-14T06:48:24Z | |
dc.date.issued | 2018 | |
dc.identifier.isbn | 978-951-39-7477-0 | fi |
dc.identifier.isbn | 978-951-39-7477-0 | |
dc.identifier.other | oai:jykdok.linneanet.fi:1874684 | |
dc.identifier.uri | https://jyx.jyu.fi/handle/123456789/58547 | |
dc.description.abstract | The underlying theme of this thesis focuses on buffer gas purification and
relevant gas-phase ion chemistry which critically affects ion beam purity at gas
cell-based radioactive ion beam facilities. The achievement of attaining a sub-
parts-per-billion level of impurity at the IGISOL facility has enabled subsequent
gas cell developments for production of the actinide elements, plutonium and
thorium, required for a program of high-resolution optical spectroscopy. Firstly,
the construction and characterization of the new IGISOL buffer gas purification
system is presented. Off-line ion beam production of plutonium and thorium
using in-gas-cell laser resonance ionization combined with filament dispensers has
resulted in successful collinear laser spectroscopy of several long-lived plutonium
isotopes and has revealed unique collisional phenomena significantly affecting
resonance laser ionization in gaseous environments.
Thorium is of particular interest due to 229Th and its low-energy nuclear isomeric
state. By stopping 229Th recoils from the alpha decay of 233U in a helium-filled
gas cell, a 229Th ground and isomeric state ion beam can be produced. The
recoil efficiency determination of two 233U sources using direct and implantation
foil gamma- and alpha-ray spectroscopy as well as surface characterization by
Rutherford back scattering (RBS) measurements have shown the importance
of good source quality. The development of a new gas cell to house several
such recoil sources is also presented, emphasizing the interplay between gas
pressure, size of the gas cell, and diffusion losses during extraction. Finally,
this thesis presents the first on-line experiments for the production of 229Th via
proton-induced fusion-evaporation reactions using a 232Th target. | fi |
dc.format.extent | 1 verkkoaineisto (xvii, 182 sivua) : kuvitettu | |
dc.language.iso | eng | |
dc.publisher | University of Jyväskylä | |
dc.relation.ispartofseries | Research report / Department of Physics, University of Jyväskylä | |
dc.relation.isversionof | Julkaistu myös painettuna. | |
dc.subject.other | ioniohjaimet | |
dc.subject.other | nuclear physics | |
dc.subject.other | gas cell | |
dc.subject.other | gas phase chemistry | |
dc.subject.other | resonance laser ionization | |
dc.title | Gas-phase chemistry, recoil source characterization and in-gas-cell resonance laser ionization of actinides at IGISOL | |
dc.type | Diss. | |
dc.identifier.urn | URN:ISBN:978-951-39-7477-0 | |
dc.contributor.yliopisto | University of Jyväskylä | en |
dc.contributor.yliopisto | Jyväskylän yliopisto | fi |
dc.contributor.oppiaine | Fysiikka | fi |
dc.relation.issn | 0075-465X | |
dc.relation.numberinseries | 2018, 5 | |
dc.rights.accesslevel | openAccess | fi |
dc.subject.yso | tutkimustekniikka | |
dc.subject.yso | hiukkaskiihdyttimet | |
dc.subject.yso | jalokaasut | |
dc.subject.yso | ydinfysiikka | |
dc.subject.yso | torium | |
dc.subject.yso | isotoopit | |