Fig. 3.

Structural temporal profiles of macromolecules. (A) Disordering through T-jump. Shown is the change of the average intensity for a set of Bragg spots (120). The changes are normalized to those measured before t₀. The temporal profiles of the intensity change were fit to multiexponential functions and the time constants were deduced, reflecting the range of rates for restructuring. We note that the 1-μs component appears only at the highest energy for heating (see Fig. S2). (B) Reordering on the ms time scale. See also Fig. 4 (and Fig. S2). (C) The expansion observed as a decrease in Bragg peaks separations and as a function of heating energy (μJ). The amplitudes plotted were obtained from both the ns and ms transients (A and B). The temperature scale shown corresponds to the energy for pulsed heating using the observed separations at different equilibrium temperatures (see Fig. S3B). (D) Energy dependence of the maximum Bragg peak intensity change, which displays a threshold at approximately 1 µJ, corresponding to the temperature of 40 °C. Above the threshold, intensity decreases linearly with energy.