AI 中文总结
该研究针对高能伽马光子的非线性布赖特-惠勒正负电子对产生过程，提出飞行聚焦脉冲方案，数值模拟显示其相较于传统固定聚焦高斯脉冲，可使不同能量光子的对产生产额提升12%至76%，效率更高。
AI 中文摘要
在强激光脉冲作用下，光子可通过称为非线性布赖特-惠勒正负电子对产生（NBWPP）的过程衰变为正负电子对。对于足够强的脉冲，高能伽马光子的NBWPP概率随相互作用时间的缩放关系优于随场强的缩放关系。与典型的固定聚焦高斯（SFG）激光脉冲不同，飞行聚焦（FF）脉冲的焦点以可编程速度移动。本文表明，与高能光子束反向传播且其焦点以光速与该束同向传播的FF脉冲，相较于等能量的SFG脉冲，能提升NBWPP的产额。数值模拟显示，焦耳级紧聚焦FF脉冲可使能量为10、20、50 GeV的光子对应的正负电子对产生产额分别提升12%、29%和76%。因此，在该参数区间内，FF脉冲比传统SFG脉冲更高效地产生正负电子对。
英文摘要
A photon can decay into an electron-positron pair in the presence of an intense laser pulse by a process known as nonlinear Breit-Wheeler pair production (NBWPP). For a sufficiently intense pulse, the probability of NBWPP for a high-energy gamma photon scales more favorably with the interaction time than with the field intensity. In contrast to typical stationary-focus Gaussian (SFG) laser pulses, a flying-focus (FF) pulse features a focal point that moves at a programmable velocity. Here, we show that a FF pulse counterpropagating with a high-energy photon beam while its focus copropagates with the beam at the speed of light enhances the NBWPP yield relative to an equal-energy SFG pulse. Numerical simulations show that a Joule-class tightly-focused FF pulse allows for an enhancement of the pair-production yield by 12\%, 29\% and 76\% for a photon of 10, 20 and 50 GeV energy, respectively. Thus, in this regime, FF pulses are more efficient at producing electron-positron pairs than conventional SFG pulses.
Comments9 pages, 7 figures
