XeF laser performance has been investigated for F
2versus NF
3as the halogen donor (fuel). The experiments were all performed in 3 AMAGAT Ne/Xe/fuel mixtures at ambient temperature and a pump rate of 132 KW/cm
3on a 1 m

-beam pumped laser. The F
2-based laser mixture has been shown to be recyclable, with no loss in laser output, while laser performance steadily degrades for NF
2-fueled mixtures under repetitively pulsed conditions. Despite the fact that F
3absorbs at the XeF wavelength, it has been demonstrated that under appropriately chosen conditions the XeF intrinsic efficiency is essentially the same (2.2 percent) for both F
2and NF
3fuels for deposited energy loadings up to at least 150 j/l. Absorption, gain, fuel burn-up, and fluorescence were also measured in order to better characterize the laser medium and to determine the major factors contributing to the efficiency.