X-ray absorption spectroscopy of mass-selected transition metal clusters using a cyclotron ion trap: An experimental setup for measuring XMCD spectra of free clusters

► An FT-ICR mass spectrometer has been combined with a soft-X-ray undulator beamline at the BESSY storage ring for determining spin and orbital magnetic moments of free mass-selected clusters. ► First L-edge absorption spectra of Nb13+, V13+ and Co22+ are shown. ► Using circularly polarized X-ray's a dichroic signal is evident for Co22+ at a cluster temperature of 100 K.