NEWS-G (New Experiments With Spheres-Gas) is a rare event search experiment using Spherical Proportional Counters (SPCs). Primarily designed for the direct detection of dark matter, this technology also has appealing features for Coherent Neutrino-Nucleus Scattering (CE$\nu$NS) studies using nuclear power plants as a neutrino source.
For both applications, an important property of the gas to characterize is the ionization yield, or quenching factor, defined as the ratio of the measured energy induced by a nuclear recoil and an electronic recoil of the same energy. Quenching factor measurements in Neon based gas mixtures are being performed at TUNL (Triangle Universities Nuclear Laboratory) using a neutron beam and an array of backing detectors. We will present the set-up and techniques for quenching factor measurements and the most recent results obtained from two measurement campaigns.