The tender X-ray spectrometer (TXS) was envisioned to fill a critical gap in online spectral energy measurements at free electron laser (FEL) facilities. The device was constructed to measure the FEL spectrum online on a shot-to-shot basis in the 2000-4000 eV photon energy range. The device is based on a von Hamos spectrometer geometry with thin foils or wires as the scattering point of the light, and bent crystals in a Bragg reflection used to focus the scattered beam onto two Jungfrau detectors.
The TXS was commissioned in November of 2020 at the Alvra end station. A preliminary view of the performance, results, and expected future performance will be presented.