Electron density measurements of electron‐beam‐pumped XeF and KrF laser mixtures

A CO2 quadrature interferometer is used to measure the temporal evolution of the electron density in XeF and KrF electron‐beam‐pumped laser mixtures (nonlasing). Measurements are obtained using a 300‐kV electron beam which delivers ≳10 A/cm2 at the foil for pulse durations ≤650 ns (FWHM). For typical XeF mixtures (99.35% Ne/0.5% Xe/0.15% F2 at 2888 Torr) the electron density varies between 3 and 4.5×1014 cm−3 during the pulse. The electron density is found to increase as the initial F2 concentration is decreased. Both 10% Kr in argon diluent and argon‐free KrF mixtures are tested. The electron density for these mixtures has the same magnitude and behavior as the typical XeF mixture.