First functionality tests of a 64 x 64 pixel DSSC sensor module connected to the complete ladder readout

摘要

The European X-ray Free Electron Laser (XFEL.EU) will provide every 0.1 s atrain of 2700 spatially coherent ultrashort X-ray pulses at 4.5 MHz repetitionrate. The Small Quantum Systems (SQS) instrument and the Spectroscopy andCoherent Scattering instrument (SCS) operate with soft X-rays between 0.5 keV -6keV. The DEPFET Sensor with Signal Compression (DSSC) detector is beingdeveloped to meet the requirements set by these two XFEL.EU instruments. TheDSSC imager is a 1 mega-pixel camera able to store up to 800 single-pulseimages per train. The so-called ladder is the basic unit of the DSSC detector.It is the single unit out of sixteen identical-units composing theDSSC-megapixel camera, containing all representative electronic components ofthe full-size system and allows testing the full electronic chain. Each DSSCladder has a focal plane sensor with 128 x 512 pixels. The read-out ASICprovides full-parallel readout of the sensor pixels. Every read-out channelcontains an amplifier and an analog filter, an up-to 9 bit ADC and the digitalmemory. The ASIC amplifier have a double front-end to allow one to use eitherDEPFET sensors or Mini-SDD sensors. In the first case, the signal compressionis a characteristic intrinsic of the sensor; in the second case, thecompression is implemented at the first amplification stage. The goal of signalcompression is to meet the requirement of single-photon detection capabilityand wide dynamic range. We present the first results of measurements obtainedusing a 64 x 64 pixel DEPFET sensor attached to the full final electronic anddata-acquisition chain.