Fluorescence background suppression

Fluorescence background suppression is yet another advantage only HPC detectors can provide in laboratory applications. In HPC detectors, X-rays with an energy below a threshold set by the user are not measured. This way, fluorescence background can be substantially reduced or even eliminated from the acquired data. When working with integrating detectors such as CCDs or so called CPADs, fluorescence suppression is not possible and data quality suffers from increased background (Fig. 2).

Fig. 2: Fluorescence suppression decreases background. Fluorescence suppression decreases background. At a threshold energy (Eth) of 11 keV (left panel), Se fluorescence causes strong background. A diffraction image acquired with a charge-integrating detector will suffer from the same fluorescence background in addition to its detector background. At Eth = 13.5 keV fluorescence is effectively suppressed (right panel), which dramatically improves the signal-to-noise ratio of the Bragg spots.