Towards microsecond XPCS at the ESRF

The objective of this proposal is to provide instrumentation which facilitates measuring microsecond dynamics of radiation-sensitive samples such as protein systems via multi-speckle X-ray photon correlation spectroscopy (XPCS) at the ESRF-EBS. We propose to purchase and integrate an XSPA RIGKAU detector for the new coherence flagship beamline ID 18 at ESRF-EBS making ideal use of the increased coherence properties of the EBS. The XSPA detector provides a sustained frame rate of 56 kHz. Running the detector in a special burst mode with lower duty cycle it is possible to trace dynamics as fast a microsecond – a time scale typical for diffusion of proteins on the nanoscale in dense cellular environments. We plan to test the new instrumental XPCS capabilities first at ID10 and ID02 including commissioning and implementation for user experiments. With the completion of ID18 we will transfer it to the new beamline. The detector will be bought from an already secured BMBF grant.