  Low pressure gaseous Time Projection Chambers (TPCs) are a viable technology
for directional Dark Matter (DM) searches and have the potential for exploring
the parameter space below the neutrino fog. Gases like CF4 are advantageous
because they contain flourine which is predicted to have heightened elastic
scattering rates with a possible Weakly Interacting Massive Particle (WIMP) DM
candidate. The low pressure of CF4 must be maintained, ideally lower than 100
Torr, in order to elongate potential Nuclear Recoil (NR) tracks which allows
for improved directional sensitivity and NR/Electron Recoil (ER)
discrimination. Recent evidence suggests that He can be added to heavier gases,
like CF4, without significantly affecting the length of 12C and 19F recoils due
to its lower mass. Such addition of He has the advantage of improving
sensitivity to lower mass WIMPs. Simulations can not reliably predict
operational stability in these low pressure gas mixtures and thus must be
demonstrated experimentally. In this paper we investigate how the addition of
He to low pressure CF4 affects the gas gain and energy resolution achieved with
a single Thick Gaseous Electron Multiplier (ThGEM).
