Creating pair plasmas with observable collective effects
Creating pair plasmas with observable collective effects
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DOI：
10.1088/1361-6587/acb080
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发表时间：
2023-01
影响因子：
2.2
通讯作者：
K. Qu;S. Meuren;N. Fisch
中科院分区：
文献类型：
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作者：
K. Qu;S. Meuren;N. Fisch
虽然现有技术还不能直接产生施温格水平的场，但实验设施已经可以利用高能电子束的洛伦兹增强来探索强场量子电动力学（QED）现象。最近的研究表明，QED级联可以在足够高的密度下产生电子-正电子对，从而表现出集体等离子体效应。集体对等离子体效应的特征可以通过等离子体引起的频率上升和激光光谱中的啁啾而呈现出精美的细节。最大限度地提高QED等离子体的特征值需要高对密度和低对能量，这符合能量密度大于1018 Jm−3的电子束与强度为1022 ~ 1023 Wcm−2的激光脉冲碰撞的配置。碰撞产生了等离子体频率较大的对，由于辐射反应和激光压力，当它们减速或反向时，频率会变得更大。本文在教程水平上解释了QED级联和激光频率上移的关键特性，同时找到了可用于产生可观测QED等离子体的最小参数。
Although existing technology cannot yet directly produce fields at the Schwinger level, experimental facilities can already explore strong-field quantum electrodynamics (QED) phenomena by taking advantage of the Lorentz boost of energetic electron beams. Recent studies show that QED cascades can create electron–positron pairs at sufficiently high density to exhibit collective plasma effects. Signatures of collective pair plasma effects can appear in exquisite detail through plasma-induced frequency upshifts and chirps in the laser spectrum. Maximizing the magnitude of the QED plasma signature demands high pair density and low pair energy, which suits the configuration of colliding an over 1018 Jm−3 energy-density electron beam with a 1022– 1023 Wcm−2 intensity laser pulse. The collision creates pairs that have a large plasma frequency, made even larger as they slow down or reverse direction due to both the radiation reaction and laser pressure. This paper explains at a tutorial level the key properties of the QED cascades and laser frequency upshift, and at the same time finds the minimum parameters that can be used to produce observable QED plasma.