Optimal Signal-to-Noise Ratio
All PILATUS3 Hybrid Photon Counting detectors are inherently free of dark current and readout noise (Fig. 1). The absence of these major sources of detector noise guarantees data with an excellent signal-to-noise ratio. Compared to charge-integrating detectors, this allows either the collection of superior data with similar exposure times or equally good data with shorter exposure times per image. A noise-free detector provides the largest benefit when recording weak signals from poorly diffracting samples or at highest resolution. The absence of detector noise is particularly beneficial in data acquisitions with weak laboratory sources.
Fig. 1: Absence of readout noise and dark current in PILATUS Hybrid Photon Counting detectors.
Images of a single PILATUS module without exposure to an X-ray source with 100 ms (a) or 1 hour (b) acquisition time. a) After a short acquisition time all pixels have zero counts because no noise is added to the readout of the image. b) After 1 hour, most pixels still have zero counts since no dark current accumulates during long exposure and no noise is added during readout. All counts in the exposure arise from general background radiation, which accounts on average for 0.2 cts/h/pixel for 450 µm sensors.