Ph.d. degree
Guilan University and Iranian Light Source Facility, Iran, 2020

Sara Dastan

Supervisor: Reza Saffari, Javad Rahighi

Optimization of parameters in Iranian Light Source Facility (ILSF) with MOGA

Keywords:

• Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics)
• Beam dynamics
• Beam Optics
• Ion sources (positive ions, negative ions, electron cyclotron resonance (ECR), electron beam (EBIS))

Abstract:

The thesis discusses the optimization of the Low-Beta lattice in the Iranian Light Source Facility (ILSF). The importance of the lattice stems from the high brightness of the beam in this structure, however, due to the existence of non-linear effects, some of the parameters do not meet the expected value, and this causes poor performance of the beam in this structure. In this dissertation, we try to optimize the dynamic aperture (stable space of particle motion) and momentum acceptance (which affects the longevity of particle beam), as the two basic parameters in beam dynamics physics. Optimization is performed by a multi-objective genetic algorithm, which is known as one of the most widely used optimization algorithms in accelerators and other sciences. Optimization results indicate an improvement in these two parameters in the storage ring. In this dissertation, first, the physics of accelerators is discussed, then non-linear elements are introduced in the accelerator. In the fourth chapter, the multi-objective genetic algorithm is introduced, and in the fifth chapter, we will introduce the ILSF storage ring and the Low-Beta lattice. The results of optimization and the effect of magnetic errors on device performance are also studied in chapter 6. Finally, chapter seven is devoted to the results of measurements in a real machine. Measurements and experiments were performed in another accelerator in Germany due to the non-completion of ILSF, in order to ensure the accuracy of the results obtained from the simulation codes which is used in this work.