Full Breakdown
Europe's First Synchrotron TES Spectrometer Begins Operation at BESSY II
6/26/2026, 11:56:48 AM
New TES Spectrometer Deployed at BESSY II
A Transition Edge Sensor (TES) spectrometer has been commissioned on the UE52-SGM beamline of the BESSY II synchrotron. Developed jointly by HZB, the Max-Planck-Institute for Chemical Energy Conversion (MPI-CEC) in Mühlheim-an-der-Ruhr, Germany, and the U.S. National Institute of Standards and Technology (NIST), it is the first TES spectrometer at a European synchrotron.
Background and Technical Motivation
X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) rely on detecting photons from a sample. Conventional wavelength-dispersive spectrometers need large photon fluxes, limiting studies to bulk or concentrated materials. TES detectors, originally for astrophysics, provide 100–1 000 times higher photon-detection efficiency, enabling measurements on atomically thin layers, nanostructures, and dilute samples.
Performance Data
The spectrometer houses 248 superconducting sensors cooled to 25 milli-Kelvin by a He4-He³ dilution refrigerator. It reduces typical XES/RIXS acquisition from hours to minutes. The instrument is installed in an ultra-high-vacuum chamber on the UE52-SGM beamline, which offers full polarization control. Prior to this, only five TES spectrometers operated worldwide—four in the United States and one in Japan.
Scientific Impact
The enhanced sensitivity enables direct probing of quantum properties in reduced dimensions—atomic monolayers, nanostructures, impurity states—and offers new insights into molecular chemistry and biology. It complements angle-resolved photoemission spectroscopy (ARPES) by providing detailed electronic-structure data for the same materials.
Official Statements & Responses
Régis Decker, responsible scientist at HZB, noted that the TES array increases detection efficiency by two to three orders of magnitude, cuts data-collection time, and enables studies of previously inaccessible samples. He announced an open call for research proposals.
Verbatim Quotes
- "The superconducting Transition Edge Sensor (TES) array photon detector that we have now put into operation at BESSY II is around 100 to 1000 times more efficient to detect photons than conventional XES and RIXS spectrometers." — Régis Decker, HZB
- "This can provide new insights into molecular chemistry or molecular biology, but also into the quantum properties of systems in reduced dimension such as atomic monolayers, nanostructures and impurities. The TES spectrometer complements methods such as ARPES, which scans the electronic band structures of such systems." — Régis Decker, HZB
- "We are looking forward to receiving exciting research proposals from our user community." — Régis Decker, HZB
What's Next
The team plans to enhance sample-preparation facilities and integrate magnetic-field modules for XMCD and RIXS-MCD experiments. The team will review incoming proposals and selected projects will commence measurements on the TES spectrometer.
