Fig. 8

Hit-finding performance of simulated hits superimposed on real background. Three representative spherical particle sizes (8, 13, 40 nm) were simulated for varying pulse intensities, particle sizes, focal properties, and hit-finding methods. We present our hit-finding method and a simpler scheme using our derived pixel mask and the total expected photon count given the pulse energy. Hit-finding was also performed in three distinct beam settings: particles hit perfectly on focus by a tophat beam (a) and the more realistic cases of a Lorentzian or a Gaussian beam hitting the particle (b and c). In all the plots, normalized scores are shown as a solid line, whereas photon count based detection is dash-dotted. For the most interesting cases of a 13 nm particle hit by a Lorentzian and Gaussian beam, we found a 50% recovery, respectively, at intensities of 2.10 × 10¹³ photons × pulse⁻¹ × μm⁻² and 9.73 × 10¹³ photons × pulse⁻¹ × μm⁻² with our statistical hit-finder; at 4.61 × 10¹³ photons × pulse⁻¹ × μm⁻² and 2.12 × 10¹⁴ photons × pulse⁻¹ × μm⁻² with the pure photon-based one