The energy of the quasi-free electron in near critical point nitrogen

Field enhanced photoemission is used to measure the density dependent quasi-free electron energy V 0 ( ρ ) in the strongly absorbing gas N2 for the first time. V 0 ( ρ ) in N2 was obtained from low density to the density of the triple point liquid, at noncritical temperatures and on an isotherm near the critical isotherm. A novel critical point effect is observed and is accurately explained by the local Wigner–Seitz model.