NQS end station

The Nano-sized Quantum Systems (NQS) end station is designed to investigate the interaction of nanoparticles, biomolecules, helium nanodroplets and rare gas or metal clusters. The end station consists of a differentially pumped vacuum system featuring interchangeable beam sources, photon, ion, and electron detectors that can be operated simultaneously.

Photon detection: DSSC - miniSSD detector

The DSSC (DEPFET sensor with signal compression) detector is able to record  X-ray images with the maximum frame rate of 4.5 MHz.  For run 6, the DSSC detector will be based on mini-SDD sensors with a dynamic range of 256 photons at 1 keV photon energy. The four modules with the overall size of 210 x 210 mm2 composed of 1024 x 1024 pixels with hexagonal shape are movable, such that the size of the central gap can be varied. 

This detector is installed in collaboration with the Detector Development group (European XFEL).

 

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:   4.5 MHz
central gap:   2 mm
distance to focus:   to be determined
vacuum compatibility:   < 10-7 mbar

Photon detection: pnCCD detector

The large-area, pn-junction Charge Coupled Device (pnCCD) detector has a very high quantum efficiency and very low readout noise. It is capable of counting single photons in the full energy range of the SQS instrument while maintaining a high dynamic range. The two modules are movable, such that both the size of the central gap as well as the distance of the detector plane to the focus can be varied. Although pulse-resolved data recording is not feasible, it possible to integrate for an entire pulse train, and reading out at 10 Hz.

This detector is installed in collaboration with R. Hartmann, L. Strüder (PNSensor GmbH), and the Detector Development group (European XFEL).

 

energy range:
  0.3 - 25 keV
detection efficiency:
  > 80 % (0.7 - 12 keV)
detector size:
  78 x 78 mm2
number of pixels:   1024 x 1024
pixel size:   75 x 75 μm2
dynamic range:   up to 10000 @ 1 keV
resolution:   single photon
readout noise:   3e- rms (high gain)
frame rate:   150 Hz
central gap:   2 mm
distance to focus:   50 -350 mm
vacuum compatibility:   < 10-8 mbar

Time-of flight and velocity map imaging spectrometers

Simultaneously to the scattered X-ray photons, ions and electrons can be detected by an ion Time-Of-Flight (iTOF) and/or a Velocity Map Imaging (VMI) spectrometer, respectively. Both are designed with conically shaped electrodes to minimize the shadow on the photon detector. The iTOF follows a standard Wiley-McLaren design. The achievable mass resolution Δm/m is about 0.1% when detecting only thermal ions, and about 0.2% for simultaneous operation of the electron VMI.

 

sample:
  gas, clusters, nanoparticles
particles:
  electrons and ions
detectors:
  MCP + phosphor screen (VMI)
  MCP + conical-shaped anode (iTOF)
max. rep. rate:
  ~100 kHz (depends on ion mass)
kin. energy range:
  up to 1 keV (VMI)
energy resolution:   3% (VMI)
mass resolution:
  0.1% (only iTOF)
  0.2% (iTOF + VMI)
acceptance angle:
  100% of 4π (VMI)