World’s Fastest Soft X-Ray Camera

European XFEL management and staff celebrate the successful installation and commissioning of the DSSC detector at the SCS instrument. From left to right: managing director Nicole Elleuche, detector group leader Markus Kuster, managing director Robert Feidenhans’l, DSSC consortium leader Matteo Porro, detector scientist Monica Turcato, SCS group leader Andreas Scherz. (Source: European XFEL)

At European XFEL near Hamburg, the world’s fastest soft X-ray camera has successfully been put through its paces. The installation, commissioning and operation of the unique detector marks the culmination of over a decade of international collaborative research and development. The so-called DSSC detector, designed specifically for the low energy regimes and long X-ray wavelengths used at the European XFEL soft X-ray instruments, will significantly expand the scientific capabilities of the instrument for spectroscopy and coherent scattering (SCS) where it is installed. It will enable ultrafast studies of electronic, spin and atomic structures at the nanoscale making use of each X-ray flash provided by European XFEL. At the end of May, the first scientific experiments using the DSSC were successfully conducted at SCS.

Diffraction image of pinholes with 707 eV photons, acquired by DSSC detector during commissioning at the SCS experiment. The DSSC detector readout frequency was 4.5 MHz. (Source: European XFEL)

The DSSC was developed by an international consortium coordinated by European XFEL. Other partners include DESY, University of Heidelberg, Politecnico di Milano, the Istituto Nazionale di Fisica Nucleare, and University of Bergamo. It is the fourth fast X-ray detector to be installed at European XFEL, and the second detector available for experiments at the SCS instrument.

Matteo Porro, DSSC project and consortium leader said: “This is a fantastic achievement in terms of detector development and it opens up unique possibilities for the photon science community. With the DSSC we have shown that it is possible to count single photons in the soft X-ray regime at the very high pulse repetition rate provided by the European XFEL. I would like to thank the DSSC consortium, who with their commitment and creativity, have made this possible. It was a privilege to work with people who provided such an extraordinary level of know-how in detector and electronics design.”

During an experiment, X-ray flashes are fired at the sample being studied. The X-rays diffract off the atoms in the sample, resulting in a distinctive pattern that is recorded and stored by the detector located behind the sample. The European XFEL delivers X-rays flashes grouped together in packets known as trains. Each train contains a maximum of 2700 flashes. Within these trains the X-ray flashes are fired in quick succession with a time difference of 220 nanoseconds.

The DSSC detector, which based on mini SDDs. (Source: DESY / K. Hansen)

At full capacity, the DSSC detector can acquire images at a rate of 4.5 million images per second, matching the speed of the X-ray flashes provided by the European XFEL. For every train the DSSC detector can store 800 one megapixel images. This makes the DSSC the fastest soft X-ray detector in the world. It was designed and built to accommodate the low energy regimes and long wavelengths unique to the soft X-ray instruments at European XFEL. The DSSC detector is based on silicon sensors and is made up of 1024 × 1024 hexagonal pixels for a total active area of 210 × 210 mm2.

The DSSC detector is currently equipped with a type of sensors called MiniSDD sensors which were produced by the Semiconductor Laboratory of the Max Planck Society in Munich. PNSensor GmbH based in Munich, recently joined the DSSC consortium to further develop another type of sensor, DePFET, for a second improved DSSC camera. This will enable an even greater level of detail to be recorded than currently possible.

“After years of design and development, it was great to see the individual detector components being assembled together at European XFEL during this past year. This was as an extremely exciting and intense time.” European XFEL Detector Group leader Markus Kuster says. “Having seen the results of the first scientific experiment with the DSSC, I am proud of the whole project team and pleased that our efforts are now bearing fruits. This is a fantastic start for the future development of the DSSC detector technology.” (Source: European XFEL)

Links: The Spectroscopy and Coherent Scattering (SCS) instrument, European X-Ray Free-Electron Laser Facility GmbH, Schenefeld, GermanyThe Chair of Circuit Design, Institute of Computer Engineering
at Heidelberg University (ZITI), Heidelberg, Germany

Speak Your Mind