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Metastability exchange optical pumping (MEOP) of ^{3}He in situ


Metastability exchange optical pumping (MEOP) of ^{3}He in situ

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dc.contributor.advisor Dohnalik, Tomasz [SAP11005099] pl
dc.contributor.author Collier, Guilhem [USOS88154] pl
dc.date.accessioned 2018-03-22T12:42:42Z
dc.date.available 2018-03-22T12:42:42Z
dc.date.submitted 2011-11-04 pl
dc.identifier.uri https://ruj.uj.edu.pl/xmlui/handle/item/52520
dc.language eng pl
dc.rights Copyright *
dc.rights.uri http://ruj.uj.edu.pl/4dspace/License/copyright/licencja_copyright.pdf *
dc.title Metastability exchange optical pumping (MEOP) of ^{3}He in situ pl
dc.title.alternative Pompowanie optyczne z wymianą metastabilności (MEOP) helu-3 in situ pl
dc.type Thesis pl
dc.place Kraków pl
dc.description.physical [4], X, 114 pl
dc.description.additional Bibliogr. s. 108-114 pl
dc.identifier.weblink http://www.fais.uj.edu.pl/documents/41628/1bc3c70a-d796-4766-9a02-cea7ca02a30b pl
dc.identifier.weblink http://web.mit.edu/cepstein/Public/PhDthesiscor.pdf pl
dc.identifier.weblink https://tel.archives-ouvertes.fr/tel-00742303/document pl
dc.abstract.en Polarized helium-3 is used as a contrast agent for lungs magnetic resonance imaging that has recently reached the pre-clinical applications. The main method to hyperpolarize 3He is the metastability exchange optical pumping (MEOP). Optical pumping is performed in standard conditions at low pressure (≈ 1 mbar) and low magnetic field (≈ 1 Gauss). In this work, the complete update of a low field polarizer dedicated to small animal lungs imaging is presented. The implementation of a new 10 W laser, new peristaltic compressor and others components resulted in a production of 3-4 scc/min for a polarization between 30 to 40%. Images of rat lungs made with better resolution and a new dynamic radial sequence are presented as a validation of the system. Since few years, MEOP has also been studied at higher pressures and higher magnetic fields in small sealed cells. It showed that, thanks to hyperfine decoupling effect induced by high magnetic field, it was also possible to efficiently polarize at higher pressure (67 mbar). Experiments done at 4.7 and 1.5 T are reported in this work. The first ones show a benefic (higher polarization values) and a negative effect (lower production rates) of the magnetic field. The seconds highlight the advantage of using an annular beam shape of the laser that matches the distribution of 23S state atoms at higher pressure. Nuclear polarization values of 66.4% at 32 mbar and 31% at 267 mbar were obtained in 20 mL sealed cells and a 10 times increase in the production rate compare to best standard conditions. These promising results were the first motivation for building a high-field polarizer working inside MRI scanner in hospital. The design and construction of such a polarizer is described in detail in the last part of the dissertation. The polarizer produces hyperpolarize 3He at 30-40% with a 4 times higher flow than the low field polarizer (10-15 scc/min). The first good quality human lungs images made in Poland with healthy volunteers are the main result of this work. pl
dc.subject.pl hel-3 pl
dc.subject.pl MEOP pl
dc.subject.pl polaryzator pl
dc.subject.pl MRI pl
dc.subject.pl obrazowanie płuc pl
dc.subject.en helium-3 pl
dc.subject.en MEOP pl
dc.subject.en polarizer pl
dc.subject.en MRI pl
dc.subject.en lungs imaging pl
dc.subject.en metastability exchange pl
dc.subject.en hyperpolarized gas pl
dc.subject.en optical pumping pl
dc.subject.en nuclear polarization pl
dc.subject.en 1083 nm pl
dc.subject.en hyperfine decoupling pl
dc.identifier.callnumber Dokt. 2011/216 pl
dc.contributor.institution Jagiellonian University. Institute of Physics. Department of Atomic Optics pl
dc.contributor.reviewer Figiel, Henryk pl
dc.contributor.reviewer Gawlik, Wojciech [SAP11005398] pl
dc.date.accession 2018-03-22 pl
dc.affiliation Wydział Fizyki, Astronomii i Informatyki Stosowanej : Instytut Fizyki im. Mariana Smoluchowskiego pl
dc.rights.original OTHER; otwarte repozytorium; ostateczna wersja autorska (postprint); w momencie opublikowania; 0 pl

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