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Spin observables have been rich sources for our understanding of nuclear struc- ture, reaction, and interactions. Non-zero nuclear spin noble-gas isotopes are suit- able for polarization. Of particular interest are the two noble-gas isotopes with a nuclear spin of 1/2, 3He and 129Xe. The hyperpolarized noble gases delivered a great tool for the growing number of applications as polarized targets in nuclear physics experiments, in Medical Resonance Imaging (MRI) and in Nuclear Mag- netic Resonance (NMR) spectroscopy studies.
Hyperpolarization of noble gases are achieved via Spin Exchange with an Opti- cally Pumped (SEOP) alkali metal vapor (Rb, K, Cs, etc.). Optical pumping is based on polarizing the valence electron of an alkali metal by the resonant absorption of a circularly polarized laser light.
This thesis describes the development and construction of a polarizer for noble gases. The main motivation was to obtain hyperpolaized 129Xe by SEOP using Rb vapor and investigate methods to increase the polarization.
We designed gas delivery system using metallic pipes with large diameter and short length to increase efficiency of gas transportation from gas tanks to a xenon polarizer. For obtaining 129Xe polarization, Helmholtz coil system providing ho- mogeneous low magnetic field of 30 G and high powered diode laser of 60 W with wavelength of 794.7 nm have been used. Detection of polarization has been per- formed by NMR spectrometer. We made a capacitance board which was used as an electrical resonator for our NMR measurements.
The xenon polarization was determined based on thermal polarization of pro- tons in water. The highest obtained 129Xe polarization was 54%. The measured longitudinal relaxation time of the hyperpolarized 129Xe was 72.3 minutes.
Thesis Advisor: Prof. Hyon-Suk Jo