Production of metastable Xenon isotopes for a new medical imaging modality, Gamma-MRI

One of the most powerful techniques developed in the field of medical diagnosis is Magnetic Resonance Imaging (MRI). This technique is able to provide information on human body functionalities by measuring the spin relaxation properties of water molecules present in the body, through the application of a high magnetic field. While the main advantage of this technique is a very good spatial resolution, it suffers from a low sensitivity to the concentration of tracers in the body. In this framework, the Gamma-MRI project aims at the development of a new medical imaging modality able to combine the good resolution of already existing MRI methodologies to the good sensitivity of Single Photon Emission Computed Tomography (SPECT) technique. Introducing radioactive hyper-polarized nuclei as contrast agent during a MRI, it would indeed be possible to gain precise information about organ functionalities via measurement of the asymmetric gamma emission of the unstable nuclei. The isotope chosen for this new technique is Xenon, due to its properties of inert gas and the spin ratio of its nuclear levels, which makes it suitable for hyperpolarization. The aim of this thesis is to investigate two different ways of producing metastable Xenon Isotopes (129mXe, 131mXe, 133mXe) at CERN. On one hand, the production and collection of radioactive ions through the ISOL technique is deeply studied at the ISOLDE facility. Experimental data from isotopes collection will be then compared to theoretical calculations from production models. On the other hand, the production of the metastable species is realized via neutron irradiation of stable Xenon at MARIA nuclear reactor in Poland. The produced samples are then characterized at ISOLDE, via development of proper transfer systems.