B 707833 C : " In situ optical monitoring of RDX nanoparticles formation during rapid expansion of supercritical CO

Appendix A. Calibration of the sensitivity of the ICCD camera Two independent techniques were used for the sensitivity calibration: Rayleigh scattering from air and Mie scattering from standard spherical polystyrene latex particles. The laser beam was focused by a spherical lens (focal length 200 mm at 248 nm), so that the focal point was in the field of view of the optical system composed of the imaging optics (a single lens or a doublet) and the camera. The calibration then consisted of the accumulation of a number of pulses in a single frame, measuring the total laser energy, and processing of the beam image formed by Rayleigh scattering. The number of scattered photons was evaluated theoretically. The Cartesian coordinates used below: x axis is parallel to the direction of the incident laser beam, y axis is along the direction from the sampling zone to the camera, and z axis is along the jet and perpendicular to the x and y directions. The optical system magnification was measured using thin wire as a scattering object and a translation stage to shift the wire by known distances. The magnification of the system was 5.1 ± 0.1.