Solid Deuterium-Hydride (HD) forms a quantum crystal whose nuclei can be polarized at high magnetic fields and low temperatures. Small impurities of H2 and D2 provide a mechanism for reaching a frozen-spin state in which polarizations can be preserved for many months with low fields and modest temperatures. The techniques and equipment needed to produce large (20 cc) polarized samples for nuclear/particle physics experiments have been developed at Brookhaven National Laboratory (BNL) over the past decade. As a polarized target, HD provides an extremely clean environment and a number of applications will be discussed. Polarized HD has been successfully used in pion photo-production experiments at the Laser-Electron-Gamma-Source (LEGS) to provide new information on the Gerasimov-Drell-Hearn-Hosoda-Yamamoto sum rule, which constrains very high energy Compton scattering, and new results will be presented. The HD staff and equipment have recently transferred to Jefferson Lab. There, HD targets will be used in a uniquely complete search for missing baryon resonances in K⁰-Λ production, which should distinguish between 3 quark and quark-diquark degrees of freedom within the nucleon. Indirect measurements at BNL suggest that HD can withstand at least modest electron currents. The use of transversely polarized HD with low holding fields can provide a unique way of measuring the Generalized Parton Distributions needed to construct a tomographic image of the proton.

ANL Physics Division Colloquium Schedule