IRIXS Spectrograph: an ultra high-resolution spectrometer for tender RIXS

by Hlynur Gretarsson (FS-PETRA-S (FS-PET-S Fachgruppe P01))




Since 2017 P01 has been operating a tender RIXS instrument, called
IRIXS, in collaboration with the Max-Planck Institute in Stuttgart. This
instrument is able to provide a record resolution of 75 meV at the Ru
L3-edge (2.840 keV) which, in many cases, is sufficient for orbital
excitations in ruthenates. However, in order to address quantum
magnetism, further improvements are required. In this talk I will
present to you our latest efforts to do exactly that. Our upgraded
instrument, called IRIXS Spectrograph, uses Bragg reflections from
asymmetrically cut crystals to reach an impressive resolution of 35 meV
while being able to image up to 120 meV of the spectrum in a single
shot. This novel spectral imaging approach overcomes the energy
resolution limitation of a traditional Rowland-type spectrometer and
therefore provides us with the blueprints towards ultra high-energy
resolution tender RIXS. If time permits I will also present some of our
latest scientific results on the bi-layer Ca3Ru2O7 and the honeycomb
lattice RuCl3.