ANL, Argonne, Illinois, USA
Sextupole magnets are used extensively in particle ac-celerators, synchrotrons, and storage rings. Good magnet-ic field quality is needed in these magnets, which requires machining the magnet parts to high precision and is the primary driver of the high fabrication costs. To minimize the fabrication costs, a magnetic field quality study from tolerance analyses was conducted. In this paper, finite element analysis (FEA) using OPERA was performed to identify key geometric factors that affect the magnetic field quality and identify the allowable range for these factors. Next, geometric and dimensional tolerance stack-up analyses are carried out using Teamcenter Variation Analysis to optimize the allocation of the geometric tol-erances to parts and assemblies. Finally, the analysis re-sults are compared to magnetic measurements of a R&D sextupole magnet.
BNL, Upton, New York, USA
SOLEIL, Gif-sur-Yvette, France
A 2.8 m long quasi-periodic APPLE II type undulator has been commissioned at the National Synchrotron Light Source II (NSLS-II) for the Electron Spectro-Microscopy (ESM) beamline in the framework of the NEXT (NSLS-II Experimental Tools) project. It provides high brilliance photon beams in circularly and linearly polarized radiation from VUV to soft X-Rays. The mechanical structure implemented to achieve the quasi-periodicity in the magnetic field profile is described together with the optimization techniques utilized to correct the undesirable phase-dependent errors. The final magnetic results are presented as well as the spectral performance of the device. Although this EPU (Elliptically Polarizing Undulator) was procured as a turn-key device, the vendor was only responsible for the mechanical frame and the control system. Sorting and assembly of the magnet modules and the magnetic field tuning - Virtual Shimming and Magic Finger - were performed at the NSLS-II Magnetic Measurement Lab.
USTC/NSRL, Hefei, Anhui, People's Republic of China