Self-absorption of synchrotron radiation in a laser-irradiated plasma
Self-absorption of synchrotron radiation in a laser-irradiated plasma
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DOI：
10.1063/5.0044766
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
T. Blackburn;A. Macleod;A. Ilderton;B. King;S. Tang;M. Marklund
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文献类型：
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作者：
T. Blackburn;A. Macleod;A. Ilderton;B. King;S. Tang;M. Marklund
当激光强度超过10^{23}~(-2)时，等离子体表面的电子被极强地加速，发出同步辐射。尽管等离子体表面的高光子、高电子密度和电磁场强度的结合使得粒子与粒子的相互作用成为可能，但这些相互作用在高强度区域的模拟中通常被忽略。在这里，我们演示了两个这样的过程的实现：光子吸收和受激发射。我们发现，对于对激光不透明的等离子体，除非被受激辐射补偿，否则光子吸收将导致同步加速器光子光谱的多keV区域完全耗尽。我们的结果推动了对强电磁场中QED现象密度依赖性的进一步研究。
Electrons at the surface of a plasma that is irradiated by a laser with intensity in excess of $10^{23}~\mathrm{W}\mathrm{cm}^{-2}$ are accelerated so strongly that they emit bursts of synchrotron radiation. Although the combination of high photon and electron density and electromagnetic field strength at the plasma surface makes particle-particle interactions possible, these interactions are usually neglected in simulations of the high-intensity regime. Here we demonstrate an implementation of two such processes: photon absorption and stimulated emission. We show that, for plasmas that are opaque to the laser light, photon absorption would cause complete depletion of the multi-keV region of the synchrotron photon spectrum, unless compensated by stimulated emission. Our results motivate further study of the density dependence of QED phenomena in strong electromagnetic fields.