Application of Sol-Gel Technology to High Pressure Polarized 3HE Nuclear Targets

High-purity sol-gel solutions have been developed to coat the interior surface of glass vessels used for polarizing ³He by spin-exchange optical pumping. Such cells have been shown to exhibit ³He longitudinal lifetimes T₁ in excess of 350 hours¹. The sol-gel technique was designed to minimize spin-relaxation due to wall collisions so that only dipole-dipole interactions between colliding ³He atoms dominate in the relaxation process. Until now, sol-gel technology had not been applied to high pressure ³He gas targets used in nuclear scattering experiments. A description of the sol-gel technique and recent developments on its integration into the production of ³He targets will be presented.