Figure 2
Dependence of Rg and I(0) on the accumulated dose. The lysozyme solution (4.9 mg ml−1) was continuously irradiated by the monochromatic X-ray, and the scattering profiles were recorded with a constant time resolution of 0.53 s. The incident flux and dose rate were 2.2 × 1011 photons s−1 and 155 Gy s−1, respectively. The increases in Rg and I(0) were expressed as FRG (open circles) and FI0 (solid circles), respectively. These definitions are given in equations (5) and (6) (see text). Above 400 Gy, both FRG and FI0 followed exponential increases, as formulated in equation (7) (broken lines). The inset represents the Guinier plots at different exposure times, i.e. the absorbed energy. The profiles from the bottom to the top correspond to 165, 820, 1645, 2470 and 3300 Gy. The lines show the least-square fitting on the S2 range, from 20 × 10−6 to 45 × 10−6 Å−2, obtained by using equation (3). |