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TY - UNPB AU - Xin, T. AU - Sun, Z. ED - Schaa, Volker RW ED - Huang, Wenhui ED - Yan, Xueqing ED - Tang, Chuanxiang ED - Li, Lu TI - Optimization Design of Photocathode Injector Assisted by Deep Gaussian Process J2 - presented at SAP2023, Xichang, China, 10-12 July 2023 CY - Xichang, China T2 - Symposium on Accelerator Physics T3 - 14 LA - english AB - The Circular Electron-Positron Collider (CEPC) has high requirements for bunch charge, transverse emittance, and longitudinal length at the injector exit. Consequently, designing a high-performance injector has become a challenge. Therefore, we propose a method of searching in a high-dimensional parameter space using a multi-objective genetic algorithm to optimize the beam at the injector exit,with an initial charge of 10 nC. Since the full simulation of bunch transportaion with spacecharge effect is extremly time consuming, we adopted the deep Gaussian process as an surrogate model to solve this issue. A total of 16 geometric parameters and 10 beam element parameters have been determined in this paper. We presented an design optimization for an injector consisting of a L-band radio frequency electron gun, a pair of solenoids, and a traveling wave tube. After calculating 6500 effective solutions, and good solutions are observed on the comprehensive performance. The corresponding transverse normalized emittance is 26.14 pi mm.mrad, and the rms beam length is 0.8 mm. Compared with the current design, the beam energy is increased by about 25\%,the emittance is reduced by about 70\%. ER -