Optimization of dynamic aperture by using non-dominated sorting genetic algorithm-Ⅱ in a diffraction-limited storage ring with solenoids for generating round beam  

作　　者：Chongchong Du Sheng Wang Jiuqing Wang Saike Tian Jinyu Wan 

机构地区：[1]Key Laboratory of Particle Acceleration Physics and Technology,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing,100049,China [2]China Spallation Neutron Source,Institute of High Energy Physics,Chinese Academy of Sciences,Dongguan,523803,China [3]University of Chinese Academy of Sciences,Beijing,100049,China

出　　处：《Radiation Detection Technology and Methods》2023年第2期271-278,共8页辐射探测技术与方法（英文）

基　　金：supported by the Guangdong Joint fund for basic and applied basic research(Guangdong-dongguan,Grant Number 2019B1515120069,2019).

摘　　要：Purpose Round beam,i.e.,with equal horizontal and vertical emittance,is preferable than a horizontally flat one for some beamline applications in Diffraction-limited storage rings(DLSRs),for the purposes of reducing the number of photons getting discarded and better phase space match between photon and electron beam.Conventional methods of obtaining round beam inescapably results in a reduction of dynamic aperture(DA).In order to recover the DA as much as possible for improving the injection efficiency,the DA optimization by using Non-dominated sorting genetic algorithm-Ⅱ(NSGA-Ⅱ)to generate round beam,particularly to one of the designed lattice of the High Energy Photon Source(HEPS)storage ring,are presented.Method According to the general unconstrained model of NSGA-Ⅱ,we modified the standard model by using parallel computing to optimize round beam lattices with errors,especially for a strong coupling,such as solenoid scheme.Results and conclusion The results of numerical tracking verify the correction of the theory framework of solenoids with fringe fields and demonstrates the feasibility on the HEPS storage ring with errors to operate in round beam mode after optimizing DA.

关 键 词：Diffraction-limited storage rings Round beam Non-dominated sorting genetic Algorithm-Ⅱ High energy photon source 

分 类 号：TL594[核科学技术—核技术及应用]