  $^{72}$As is a promising positron emitter for diagnostic imaging that can be
employed locally using a $^{72}$Se generator. However, current reaction
pathways to $^{72}$Se have insufficient nuclear data for efficient production
using regional 100-200 MeV high-intensity proton accelerators. In order to
address this deficiency, stacked-target irradiations were performed at LBNL,
LANL, and BNL to measure the production of the $^{72}$Se/$^{72}$As PET
generator system via $^{75}$As(p,x) between 35 and 200 MeV. This work provides
the most well-characterized excitation function for $^{75}$As(p,4n)$^{72}$Se
starting from threshold. Additional focus was given to report the first
measurements of $^{75}$As(p,x)$^{68}$Ge and bolster an already robust
production capability for the highly valuable $^{68}$Ge/$^{68}$Ga PET
generator. Thick target yield comparisons with prior established formation
routes to both generators are made. In total, high-energy proton-induced cross
sections are reported for 55 measured residual products from $^{75}$As, Cu, and
Ti targets, where the latter two materials were present as monitor foils. These
results were compared with literature data as well as the default theoretical
calculations of the nuclear model codes TALYS, CoH, EMPIRE, and ALICE. Reaction
modeling at these energies is typically unsatisfactory due to few prior
published data and many interacting physics models. Therefore, a detailed
assessment of the TALYS code was performed with simultaneous parameter
adjustments applied according to a standardized procedure. Particular attention
was paid to the formulation of the two-component exciton model in the
transition between the compound and pre-equilibrium regions, with a linked
investigation of level density models for nuclei off of stability and their
impact on modeling predictive power.
