BESSY II launches New Filling Pattern in User Mode
The new filling pattern consists of a Hybrid (or Camshaft) bunch at 4 mA (Chopper) in the center of the 200 ns wide ion clearing gap followed by the so-called PPRE-bunch of variable transverse excitation at 3 mA and 84 ns later. Together with the usual multibunch filling and the 3 slicing bunches on top of the multibunch train, now 302 out of 400 possible buckets in the storage ring are filled and topped up. © HZB
Since July 2015 BESSY II has been providing a new bunch filling pattern in Top-Up mode. It will open new opportunities especially for research teams dealing with time-resolved x-ray experiments. It is of significant importance for us and the community anticipating BESSY VSR.
Apart from ultrafast experiments at the Femtoslicing facility (slicing bunches) and x-ray pump-probe applications with the hybrid (or camshaft) bunch, now also time-of-flight experiments with the ARTOF and other instruments that use the pulse selection of the MHz-Chopper [1] can be carried out in normal mode.
The new additional bunch in the dark gap arriving 84 ns after the chopper bunch can be transversally excited to support time-resolved Photoelectron- and X-ray spectroscopy based on the PPRE-technique [2]. Having such time-resolved methods at hand in the regular usermode we are even now able to take a glimpse into future operation modes at BESSY VSR.
- Superconducting TES array X-ray spectrometer goes into operation at BESSY IIEurope's first and only TES-spectrometer at a synchrotron source is now in operation at BESSY II, developed within a collaboration between the HZB, the MPI-CEC (Mühlheim-an-der-Ruhr, Germany) and the NIST (Boulder CO, USA). The photon detection efficiency of the new instrument exceeds that of wavelength-dispersive X-ray emission spectrometers by a factor of 100 to 1000. It will be used to investigate the electronic properties of atomically thin layers, nanostructures and highly diluted atomic and molecular samples. The team is looking forward to receiving exciting research proposals from the user community.
- Magnon momentum microscopy: A new window into nanoscale spin-wavesAn international team lead by the Max Born Institute has developed a new type of momentum microscopy to image magnons — the quanta of collectively excited spins — directly in two-dimensional reciprocal space using soft X-rays. Measurements have taken place at BESSY II and PETRA III, first author ist the HZB physicist Steffen Wittrock. Owing to its remarkable sensitivity, simplicity, and access to nanometer-scale wavelengths, this novel technique establishes a powerful and versatile platform for exploring nonlinear magnon interactions, which are promising for future computing schemes.
- BESSY II: How intrinsic oxygen shortens the lifespan of solid-state batteriesAlthough solid-state batteries (SSBs) demonstrate high performance and are intrinsically safe, their capacity currently declines rapidly. A team from the TU Wien, Humboldt-University Berlin and HZB has now analysed a TiS₂|Li₃YCl₆ solid-state half-cell in operando at BESSY II using a special sample environment that allows for non-destructive investigation under real operating conditions. Data obtained by combination of soft and hard X-ray photoelectron spectroscopy (XPS and HAXPES) revealed a new degradation mechanism that had not previously been identified in solid-state batteries. They have gained some surprising insights, particularly regarding the harmful role played by intrinsic oxygen. This study provides valuable information for improving design and handling of such batteries.