Zhou Shiyu, Ding Siqin, An Weiming, Su Qianqian, Hua Jianfei, Li Fei, Mori Warren B, Joshi Chan, Lu Wei
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
Research (Wash D C). 2025 Sep 9;8:0878. doi: 10.34133/research.0878. eCollection 2025.
Plasma wakefield acceleration in the nonlinear blowout regime has achieved marked milestones in electron beam acceleration, demonstrating high acceleration gradients and energy efficiency while preserving excellent beam quality. However, this regime is deemed unsuitable for achieving positron acceleration of comparable results, which is vital for future compact electron-positron colliders. In this article, we find that an intense positron beam loaded at the back of beam-driven blowout cavity can self-consistently induce the focusing field and flatten the longitudinal wakefield, leading to stable, high-efficiency, and high-quality positron acceleration. This is achieved through the formation of an on-axis electron filament induced by positron beam load, which shapes the plasma wakefield in a distinct way compared to electron beam load in the blowout regime. Via a nonlinear analytic model and numerical simulations, we explain the novel beam loading effects of the interaction between the on-axis filament and the blowout cavity. High-fidelity simulations show that a high-charge positron beam can be accelerated with >20% energy transfer efficiency, ~1% energy spread, and ~1 mm·mrad normalized emittance, while considerably depleting the energy of the drive beam. The concept can also be extended to simultaneous acceleration of electron and positron beams and high transformer ratio positron acceleration as well. This development offers a new route for the application of plasma wakefield acceleration into particle physics.
非线性爆轰 regime 下的等离子体尾场加速在电子束加速方面已取得显著里程碑，展现出高加速梯度和能量效率，同时保持了优异的束流品质。然而，该 regime 被认为不适用于实现具有可比结果的正电子加速，而这对于未来的紧凑型电子 - 正电子对撞机至关重要。在本文中，我们发现加载在束流驱动爆轰腔后部的强正电子束能够自洽地诱导聚焦场并使纵向尾场变平，从而实现稳定、高效且高质量的正电子加速。这是通过由正电子束负载诱导形成的轴上电子丝来实现的，与爆轰 regime 中的电子束负载相比，它以独特的方式塑造了等离子体尾场。通过非线性解析模型和数值模拟，我们解释了轴上丝与爆轰腔之间相互作用的新型束流加载效应。高保真模拟表明，高电荷正电子束能够以大于 20%的能量转移效率、约 1%的能量分散和约 1 mm·mrad 的归一化发射度进行加速，同时显著消耗驱动束的能量。该概念还可扩展到电子束和正电子束的同时加速以及高变压器比正电子加速。这一进展为将等离子体尾场加速应用于粒子物理学提供了一条新途径。
