Preliminary Design of a Cryogen-Free 6.6 T Superconducting Wavelength Shifter

A cryogen-free 6.6 T Superconducting Wavelength Shifter (SWLS) is currently being designed to produce photons with a critical energy higher than 39 keV for the future hard X-ray beamline of Sirius, a new 4th generation Brazilian light source. The magnet is based on NbTi coils and holmium poles with an operating margin above 20% at 5 K. A magnetic gap of 7 mm in the central pole was required to achieve a narrow peak field profile (FWHM = 29.8 mm), which did not affect the emittance of the machine. The device is designed to reuse several parts and equipment from a deactivated Superconducting Wiggler. The preliminary design of the SWLS is presented, focusing on electromagnetic, mechanical, thermal, and quench protection proposals.