  The molecular ion ThF$^+$ is the species to be used in the next generation of
search for the electron's Electric Dipole Moment (eEDM) at JILA. The
measurement requires creating molecular ions in the eEDM sensitive state, the
rovibronic ground state $^3\Delta_1$, $v^+=0$, $J^+=1$. Survey spectroscopy of
neutral ThF is required to identify an appropriate intermediate state for a
Resonance Enhanced Multi-Photon Ionization (REMPI) scheme that will create ions
in the required state. We perform broadband survey spectroscopy (from 13000 to
44000~cm$^{-1}$) of ThF using both Laser Induced Fluorescence (LIF) and $1+1'$
REMPI spectroscopy. We observe and assign 345 previously unreported vibronic
bands of ThF. We demonstrate 30\% efficiency in the production of ThF$^+$ ions
in the eEDM sensitive state using the $\Omega = 3/2$ [32.85] intermediate
state. In addition, we propose a method to increase the aforementioned
efficiency to $\sim$100\% by using vibrational autoionization via
core-nonpenetrating Rydberg states, and discuss theoretical and experimental
challenges. Finally, we also report 83 vibronic bands of an impurity species,
ThO.
