Absorbance measured for (a) 20 × 1 s burns and (b) a single 20 s burn. The absorbed dose per 1 s exposure was 287 kGy. The cumulative dose over 20 s was thus 5.74 MGy. (a) The multiple burns show a progressively smaller change in absorption for the same absorbed dose and rapid loss of was observed after each pulse. (b) The single continuous 20 s burn highlights the post-exposure decay of the disulfide peak, which is best described by a two-rate model, in agreement with previous observations (Owen et al., 2011; Beitlich et al., 2007).