LBNL, Berkeley, California, USA
SLAC, Menlo Park, California, USA
An analysis is performed on various possible errors that may occur throughout a hybrid undulator. Of particular significance is the scaling of the various errors with variations in the gap of the device. Tuning strategies are considered for the mitigation of these errors for the entire range of usable gap. Sorting strategies for the reduction of the initial errors in the undulator are also considered. Specifically, the effectiveness of the sorting algorithm is evaluated with respect to the number of permanent magnet blocks used per pole as well as the size and distribution of the block population. The results of this analysis are applied to the LCLS-II undulators to determine the required machining and positioning tolerances and viable tuning strategies in order to meet the design requirements.
SLAC, Menlo Park, California, USA
LBNL, Berkeley, California, USA
The SLAC National Accelerator Laboratory is constructing the new FEL user facility LCLS-II, as a major upgrade to the Linear Coherent Light Source (LCLS). The upgrade will include two new Free Electron Lasers, to generate soft (SXR) and hard X-ray (HXR) SASE FEL radiation, based on planar, variable gap hybrid undulators with two different undulator periods (SXR 55 mm, HXR 32 mm). An systematic FEL tolerance analysis for the undulator lines, including tuning, alignment, yaw deformation, and phase correction tolerances has been performed. The methods and results are presented in this work.
THOAI2
LBNL, Berkeley, California, USA
Undulator technology plays a critical role in FEL performance. The desire to provide a specific range of photon wavelengths for science applications constrains the design space of electron beam energy and undulator tuning capabilities. In particular, the coupling between photon wavelength, beam energy, and undulator period and strength indicates that undulator technology is a major cost driver in the design of FEL facilities. Superconducting undulators have the potential to significantly improve upon performance of current state-of-the-art undulator technologies being implemented in the first FEL facilities. Here we review the status of superconducting undulator technology, including developments in the areas of helical, planar, and variable polarizing superconducting undulator concepts at a variety of laboratories around the world. Implications of superconducting undulator performance for FEL applications are described. Finally, the major technological hurdles that remain to be addressed prior to implementation in FEL facilities are outlined, together with a summary of current R&D efforts.
