AN ELLIPTIC WIGGLER FOR SPRING-8

This paper presents a study for the realization of an elliptical multipole wiggler to be installed on the pilot beamline dedicated to material science at SPring-8. Such a wiggler should meet the requirements of third generation synchrotron sources (e.g., large horizontal aperture), as it uses a planar structure (two jaws above and below the vacuum chamber). Compared to the APPLE concept proposed by Sasaki, this new wiggler exhibits similar performances: 65% (85%/90%) circular polarization rate can be obtained up to 300 keV (200/150 keV) with high brilliance (≳1015photons/s/0.1%/mr 2/mm2). Moreover this new design is easier to characterize than APPLE, since the sources of vertical and horizontal magnetic fields are independent. The effects of the magnet interactions (e.g., demagnetization in magnets and the consecutive loss of field) are not considered in the following but should be addressed in a future paper. © 1995 American Institute of Physics.