Speaker
Description
Since the spectral quality from cryogenic permanent magnet undulators (CPMUs) can be superior to that of in-vacuum undulators (IVUs), a PrFeB-based CPMU with a period length of 15 mm has been constructed for the Taiwan Photon Source (TPS) to provide high brilliant X-rays. Two cryo-coolers, each with a cooling capacity of 200W at 80 K, provide high temperature stability in the presence of external heat loads of up to a few hundred watts. At the lowest PM temperature of 56 K, the CPMU can generate an effective magnetic field of 1.34 T in a gap of 4 mm. An in-situ and vacuum compatible field measurement system has been developed to characterize the magnetic fields at cryogenic temperatures and allowing corrections of gap errors. The relevant technology and performance of the TPS-CPMU will be presented including observations associated with phase errors and magnetic field quality at cryogenic temperature.
