Characteristics of Solid Ammonia for Nuclear Scattering Experiments*

Irradiated Solid ammonia, recognized for its high radiation resistance and dense paramagnetic centers, is an ideal material for polarized nuclear scattering experiments. This study examines crucial characteristics of polarized solid ammonia. The nuclear longitudinal relaxation time (T1) above the helium bath temperature (1K) is considered to understand the target material's activation energy and thermal depolarization effects. The dilution factor, another critical characteristic of the target material, represents a particular spin reservoir's total available nuclear content and is essential for proper calculation of the polarizable polarization observables. Additionally, ammonia's thermal conductivity and Kapitza resistance are critical for managing the heat load and cooling of the target during beam interactions. These characteristics are vital for optimizing solid ammonia's performance in polarized nuclear and high energy scattering experiments of many processes. In this presentation, I will discuss these essential characteristics of solid ammonia and its use in fixed target experiments.