Brute Force Polarization of 129Xe

Hyperpolarized ¹²⁹Xe has numerous applications in Nuclear magnetic resonance (NMR) and magnetic resonance imaging(MRI). As an alternative to the laser optical pumping method of production of hyperpolarized ¹²⁹Xe gas, we have investigated the brute force technique which uses a very high magnetic field and millikelvin temperatures. One obstacle to this technique is the extremely long spin lattice relaxation times of nuclei in solids at very low temperature. We exploit the fact that liquid ³He can be used as an effective relaxant to enable ¹²⁹Xe to be spin polarized on a high surface area substrate in a few hours. We are able to identify the contributions of different atomic layers to the magnetization by analyzing the ¹²⁹Xe NMR spectrum. Furthermore, the addition of ⁴He allows us to turn off the relaxation mechanism, thereby preserving the polarization. The technique could be applied to nuclei other than ¹²⁹Xe.