Data scaling and temperature calibration in time-resolved photocrystallographic experiments.

Experiments in which structural changes in crystals are induced by pulsed-laser exposure involve an increase in sample temperature due to the dissipation of the deposited excess energy. The heat increase is especially pronounced when a large number of pulses is needed, as in pseudo-steady-state experiments conducted at conventional sources, but not negligible in synchrotron studies in which very short laser exposures may be adequate. The relative scaling of the light-ON and light-OFF data and the correction for temperature differences between the two sets are discussed.