Producing $^{229}$Pa via $^{232}$Th(p\{20-30~MeV\},4n)$^{229}$Pa for use in a PaF$^{n+}_x$ based Nuclear Schiff Moment Measurement

Protactinium-229 is one of the most promising nuclei for hadronic electric dipole moment studies due to its octupole deformation and near‑degenerate ground state parity doublet, which together yield an extremely enhanced nuclear Schiff‑moment (NSM), by a factor of $\sim\mathcal{O}(10^5)$ compared to $^{199}$Hg. In order to produce $^{229}$Pa, metallic $^{232}$Th foils and $^{232}$ThF$_4$ sputtering targets are irradiated with 20--30~MeV protons. After cooldown, we laser-ablate the top layer of each sample in a UHV chamber back-filled with SF$_6$ or CF$_4$. Ablated Protactinium ions rapidly form PaF$_x^{n+}$ molecules that are detected with a quadrupole mass spectrometer, alongside ThF$_x^{n+}$ from the target. Ratios of summed Pa-bearing to Th-bearing partial pressures, combined with integrated incident proton beam current, SRIM proton beam stopping-power profiles, and ablation modeling, yield an independent determination of the $^{232}$Th(p,4n)$^{229}$Pa cross-section without chemical separation. These cross-sections are vetted against TALYS estimates. We also performed simulation using LISE++ to understand the fragmentation of $^{232}$Th and $^{19}$F in the sputtering target upon exposure to the proton beam. These measurements are critical for understanding the production of $^{229}$PaF$_3^+$, iso-electronic with RaF for which a laser cooling scheme has already been identified. We present progress on an integrated program that (i) measures the $^{232}$Th(p,4n)$^{229}$Pa production cross section between 20--30~MeV proton incident energies, and (ii) establishes conditions for efficient $^{229}$PaF$_x^{n+}$ formation for future trapped-ion NSM measurement.