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DSSC detector

The DSSC is a 1 Megapixel large area detector that is able to record soft X-ray images at the maximum frame rate of the FEL at 4.5 MHz. It is composed of 4 movables quadrants, each containing 4 ladders composed of two monolithic sensors with hexagonal shaped pixels. Two different sensor version exist. The first one (see article here) is based on Miniaturized Silicon Drift Detector (MiniSDD) pixel sensors and provides a linear response. The second one (see article here) is based on Depleted Field Effect Transistor (DEPFET) and provides non-linear response, giving it it’s name (DSSC = DEPFET Sensor with Signal Compression).

In pump-probe experiment, the MiniSDD DSSC is equipped with an additional Al filter making the minimum gaps between quadrants 4mm.

miniSDD parameters

energy range: 0.5 - 6 keV
detection efficiency: 100%
detector size: 210 x 210 mm2
number of pixels: 1024 x 1024
pixel size: ~ 204 x 236 μm2 (hexagonal)
dynamic range: 256 @ 1 keV
resolution: single photon (> 1 keV)
readout noise: depends on rep. rate
frame rate: Max. 4.5 MHz
central gap: 4 mm
distance to focus: 610 mm to 5429 mm
vacuum compatibility: <10-7 mbar

Sample-detector distance [mm]
Minimum
Maximum
DSSC
431
5429

The available q range depends on the sample-detector distance, the detector size, the dimension of the beamstop and the photon energy. The q range can be calculated for DSSC detector.