中国物理B ›› 2023, Vol. 32 ›› Issue (4): 44101-044101.doi: 10.1088/1674-1056/acae79

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Plasma density transition-based electron injection in laser wake field acceleration driven by a flying focus laser

Pan-Fei Geng(耿盼飞)1,2, Min Chen(陈民)1,2,†, Xiang-Yan An(安相炎)1,2, Wei-Yuan Liu(刘维媛)1,2, Xin-Zhe Zhu(祝昕哲)1,2, Jian-Long Li(李建龙)1,2, Bo-Yuan Li(李博原)1,2, and Zheng-Ming Sheng(盛政明)1,2   

  1. 1 Key Laboratory for Laser Plasmas(Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China;
    2 Collaborative Innovation Center of IFSA(CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
  • 收稿日期:2022-11-16 修回日期:2022-12-16 接受日期:2022-12-27 出版日期:2023-03-10 发布日期:2023-03-30
  • 通讯作者: Min Chen E-mail:minchen@sjtu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11991074, 12225505 and 12135009). The simulations were performed on the π 2.0 supercomputer in the Center for High Performance Computing at Shanghai Jiao Tong University.

Plasma density transition-based electron injection in laser wake field acceleration driven by a flying focus laser

Pan-Fei Geng(耿盼飞)1,2, Min Chen(陈民)1,2,†, Xiang-Yan An(安相炎)1,2, Wei-Yuan Liu(刘维媛)1,2, Xin-Zhe Zhu(祝昕哲)1,2, Jian-Long Li(李建龙)1,2, Bo-Yuan Li(李博原)1,2, and Zheng-Ming Sheng(盛政明)1,2   

  1. 1 Key Laboratory for Laser Plasmas(Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China;
    2 Collaborative Innovation Center of IFSA(CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
  • Received:2022-11-16 Revised:2022-12-16 Accepted:2022-12-27 Online:2023-03-10 Published:2023-03-30
  • Contact: Min Chen E-mail:minchen@sjtu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11991074, 12225505 and 12135009). The simulations were performed on the π 2.0 supercomputer in the Center for High Performance Computing at Shanghai Jiao Tong University.

摘要: By using a high-intensity flying focus laser, the dephasingless [Phys. Rev. Lett. 124 134802 (2020)] or phase-locked [Nat. Photon. 14 475 (2020)] laser wakefield acceleration (LWFA) can be realized, which may overcome issues of laser diffraction, pump depletion, and electron dephasing which are always suffered in usual LWFA. The scheme thus has the potentiality to accelerate electrons to TeV energy in a single acceleration stage. However, the controlled electron injection has not been self-consistently included in such schemes. Only external injection was suggested in previous theoretical studies, which requires other accelerators and is relatively difficulty to operate. Here, we numerically study the actively controlled density transition injection in phase-locked LWFA to get appropriate density profiles for amount of electron injection. The study shows that compared with LWFA driven by lasers with fixed focus, a larger plasma density gradient is necessary. Electrons experience both transverse and longitudinal loss during acceleration due to the superluminal group velocity of the driver and the variation of the wakefield structure. Furthermore, the periodic deformation and fracture of the flying focus laser in the high-density plasma plateau make the final injected charge also depend on the beginning position of the density downramp. Our studies show a possible way for amount of electron injection in LWFA driven by flying focus lasers.

关键词: density transition injection, laser wakefield acceleration, flying focus laser

Abstract: By using a high-intensity flying focus laser, the dephasingless [Phys. Rev. Lett. 124 134802 (2020)] or phase-locked [Nat. Photon. 14 475 (2020)] laser wakefield acceleration (LWFA) can be realized, which may overcome issues of laser diffraction, pump depletion, and electron dephasing which are always suffered in usual LWFA. The scheme thus has the potentiality to accelerate electrons to TeV energy in a single acceleration stage. However, the controlled electron injection has not been self-consistently included in such schemes. Only external injection was suggested in previous theoretical studies, which requires other accelerators and is relatively difficulty to operate. Here, we numerically study the actively controlled density transition injection in phase-locked LWFA to get appropriate density profiles for amount of electron injection. The study shows that compared with LWFA driven by lasers with fixed focus, a larger plasma density gradient is necessary. Electrons experience both transverse and longitudinal loss during acceleration due to the superluminal group velocity of the driver and the variation of the wakefield structure. Furthermore, the periodic deformation and fracture of the flying focus laser in the high-density plasma plateau make the final injected charge also depend on the beginning position of the density downramp. Our studies show a possible way for amount of electron injection in LWFA driven by flying focus lasers.

Key words: density transition injection, laser wakefield acceleration, flying focus laser

中图分类号:  (Laser-driven acceleration?)

  • 41.75.Jv
52.38.Kd (Laser-plasma acceleration of electrons and ions) 52.65.Rr (Particle-in-cell method)