Evaporation of solid polarized HD and pure ortho‐D2

Evaporation of metastably spin‐polarized solid H↑D or o‐↑D2 provides polarized ↑D gas sources which can serve as internal polarized targets of densities substantially higher than are currently realized with atomic beam or optically‐pumped polarized gas sources. The gas can be jetted directly to the beam or its density can be enhanced in a storage cell. A novel target injection method for which the new polarized solids are uniquely suited consists of repeatedly injecting small solid pellets into the particle beam region, similar in concept to the pellet method of fuel injection for fusion reactors. The pellets can be ablated anywhere within a storage cell, if one is used, or in the absence of a storage cell, in close proximity to the particle beam trajectory, thereby providing more efficient target utilization. The method of producing the spin‐polarized hydrogens solids is also briefly reviewed.