Fig. 3: X-ray scattering from water.

a Single split-pulse scattering pattern in a 100 × 100 pixel region of interest at around Q = 2.0 Å⁻¹ with I_tot = 3.3 µJ and Δt = 0.0 ps. The vertical and horizontal directions correspond to Q-direction and the azimuthal direction, respectively. b Histogram of the charge (in units of analog-to-digital units (ADU)) per shot in a 1024 × 512 pixel region. The blue solid line is the average histogram of the 287,982 raw images, and the red dashed line is after the droplet algorithm has been applied. The single-photon event corresponds to 595 ADU. c The number of photons at each pixel per shot obtained by averaging 35,899 shots with Δt = 0.0 ps and 〈I_tot〉 = 7.9 µJ. (red lines). The area around Q = 2.0 Å⁻¹ was covered by a single MPCCD and that around Q = 3.0 Å⁻¹ was covered by a dual MPCCD⁴². The solid black line is the estimation of X-ray elastic scattering using the result of high-energy X-ray diffraction intensity profile⁴⁷, the thickness of the sample, the X-ray energy, the size of a pixel, and the average number of X-ray photons for a single shot. The dashed line is × 0.64 of the solid line.