Temperature effects on the perturber induced shift of dopant ionization energies in He and Ne

► Dopant and temperature dependence in ΔD(ρP) is shown to be caused by polarization. ► Quasi-free electron energy V0(ρP) in He and Ne is extracted from ΔD(ρP). ► V0(ρP) in low to medium density He and Ne is fitted by the local Wigner-Seitz model.