Absorption at 248 nm by Kr2F*

The cross section for absorption of 248 nm radiation by the lowest bound electronic excited (42Γ) of the rare gas halide trimer Kr2F* has been measured to be 7.2×10−19 cm2. This is an order of magnitude smaller than the value which is typically used in KrF kinetics codes [cf. T. H. Johnson and A. M. Hunter, J. Appl. Phys. 51, 2406 (1980)]. The lower absorption cross section leaves unaccounted the observed nonsaturable absorption in long pulse KrF lasers.