EFFECT OF THE BEAM EMITTANCE ON THE PHOTON FLUX AND BRIGHTNESS OF SYNCHROTRON RADIATION EMITTED BY THE UNDULATOR U20

Abstract

This thesis investigates the radiation performance of the U20 undulator for a potential future installation at SESAME, and the magnetic design of the sector dipole for the PERLE. The study aims to evaluate how beam parameters affect photon flux and brightness, and to provide a validated magnetic model for PERLE. Using SRW simulations, the U20 undulator was analyzed under realistic SESAME beam conditions, showing that reducing the horizontal emittance significantly enhances light output: the fundamental harmonic increased from 2.46×10^13 to 3.28×10^13 while the brightness improved by nearly an order of magnitude. These performance gains can be directly adopted by SESAME in future upgrades. In the second part, the PERLE dipole magnet was designed and optimized using Opera 3D, achieving uniform field quality across the Good Field Region and confirming an efficient turbulent water-cooling regime (Re = 9685). The resulting magnetic model forms part of the PERLE Technical Design Report (TDR). Overall, the outcomes of this work contribute to improving undulator performance at SESAME and advancing magnet development for PERLE.