通过结合气体射流内的直接激光加速与固体靶相互作用改善贝特-海特勒正电子产生与保留
Improved Bethe-Heitler positron creation and retention by combining direct laser acceleration and solid target interaction within a gas jet
AI总结：
针对现有单激光级正电子产生构型的束质量有限、粒子数低问题，提出结合贝特-海特勒对产生与等离子体通道内直接激光加速（DLA）的方法，通过半解析模型和PIC模拟优化正电子注入与保留，使保留率提升8倍，建立了稳健单级正电子束获取方案。
摘要：
下一代拍瓦级激光器为在全光学环境中实验研究正电子产生和加速提供了机遇。已有多种构型被提出用于在单激光级中产生并加速正电子，但这些构型产生的正电子束质量有限且粒子数较低。本文提出了通过贝特-海特勒对产生获得正电子、并在等离子体通道中利用直接激光加速（DLA）进行加速时，改善其注入与保留的方法。研究首先引入半解析模型，预测该高度非线性区域的激光能量损耗；通过粒子模拟（PIC）证明，加速电子可在通道内引发电荷反转，进而实现正电子捕获与加速；还研究了激光聚焦位置、通道壁密度、靶箔位置和靶厚度对正电子产生与保留的影响。该构型的正电子保留率较此前研究提升8倍，且总体产生的正电子数量更高。本工作建立了稳健的单级正电子束获取方法，为拍瓦级激光器实验及正负电子碰撞、量子电动力学（QED）级联等潜在应用开辟了新途径。
英文摘要：
The next generation of Petawatt-class lasers presents the opportunity to study positron production and acceleration experimentally, in an all-optical setting. Several configurations were proposed to produce and accelerate positrons in a single laser stage. However, these configurations have yielded limited positron beam quality and low particle count. This paper presents methods for improving the injection and retention of positrons obtained via Bethe-Heitler pair production and accelerated using direct laser acceleration (DLA) in a plasma channel. The work first introduces a semi-analytical model which predicts laser energy depletion in this highly nonlinear regime. We demonstrate through PIC simulations that accelerated electrons can induce charge inversion within the channel, leading to positron trapping and acceleration. We investigate how laser focusing position, channel wall density, target foil position and target thickness influence positron creation and retention. Our configuration can achieve an 8-fold increase in positron retention compared to previous studies and a higher number of positrons produced overall. This work establishes a robust, single-stage approach for obtaining positron beams, opening new avenues for experiments with Petawatt-class lasers and potential applications in electron-positron collisions and QED cascades.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
