Iranian Light Source Facility Storage Ring Low Field Magnets

Abstract

Iranian Light Source Facility (ILSF) is a 3 GeV Synchrotron light source with the circumference of 489.6m. Using locally available material and the emittance of less than 1 nm-rad are two main points of the ILSF storage ring lattice, consisting of 56 low field pure bending magnets, 252 quadrupoles and 196 sextupoles with additional coils for the correctors and skew quadrupoles. The physical designs of these magnets have been performed relying on two dimensional codes POISSON [1] and FEMM [2]. Three dimensional RADIA [3] was practiced too, to audit chamfering values. INTRODUCTION Using locally accessible materials has bound the beam dynamic group to utilize the magnets with upper field limits of 1.6 T for the dipoles, 0.8 T for the pole tip of quadrupoles and 0.4 T for the pole tip of sextupoles in their design [4].No gradient in the low field dipoles has been considered in the design stage of the lattice to ease alignment. The focusing in horizontal and vertical direction is performed in each super period with 8 focusing quadrupoles in three families and 10 defocusing quadrupoles in 4 families, with 14 sextupoles within 6 families [4]. All quadrupole magnets have the same cross section. This is the same for sextupole magnets that differ by their sextupole components and lengths. STORAGE RING MAGNETS Dipoles Through a none symmetric standard shim the field quality would be lower than 0.02% within the good field region ±18mm. Figure 1 shows the magnet’s dimensions and magnetic field lines inside one half of the dipole as simulated by “POISSON” code. Figure 1: Magnetic field lines and geometry of the dipole magnet in ILSF. Stainless steel M800-100A, a low-carbon ( The magnetic design of the magnets for ILSF storage ring is done and the magnets are now in the production phase. Using typical 2-D codes, POISSON and FEMM along with the 3-D code, RADIA, to provide an authentic investigation on the magnets end fields have been fruitful. REFERENCES [1] uspas.final.gov/PCprog [2] www.FEMM.info [3] www.esrf.fr/machine.groups/inserion_devices/Codes/ Radia/Radia [4] H. Ghasem, F. Saeidi, I. Ahmadi, “Low field low emittance lattice for the storage ring of Iranian Light Source Facility”, Journal of Instrumentation 8, P02023 (2013). [5] Jack Tanabe, “Iron Dominated Electromagnets Design, Fabrication, Assembly and Measurements”, SLAC-R-754, June 2005.