论文标题
从超高强度激光 - 血浆相互作用以及与薄箔目标中的Bremsstrahung竞争的同步辐射
Synchrotron radiation from ultrahigh-intensity laser-plasma interactions and competition with Bremsstrahlung in thin foil targets
论文作者
论文摘要
通过粒子中的数值模拟，我们研究了在超高强度条件下与多用途激光系统相关的激光 - 血浆相互作用中高能量光子的发射。我们首先检查了从密度和大小不同的激光驱动等离子体中同步辐射的特征。特别是，我们表明并解释了辐射光子对等离子体的透明度或不透明度的角度分布的依赖性。然后，我们研究铜箔中同步器和Bremsstrahung排放量的竞争，该铜箔目标是$ 10^{22} \，\ rm w \，cm^{ - 2} $，$ 50 \，\ rm rm fs $ fs $ fs $ fs $ fs $ fs $ fs $ laser脉冲。观察到同步加速器的发射是最大化的，对于几美元，\ rm nm $的目标厚度，接近相对论透明度阈值，并被Bremsstrahlung取代，目标是几美元$ m厚的目标。以最佳效率，发现两种机制都将激光能量的大约1％辐射到能量以上的能量超过$ 10 \，\ rm kev $的光子中。根据超快目标动力学，对它们的能量和角光谱进行了彻底分析。
By means of particle-in-cell numerical simulations, we investigate the emission of high-energy photons in laser-plasma interactions under ultrahigh-intensity conditions relevant to multi-petawatt laser systems. We first examine the characteristics of synchrotron radiation from laser-driven plasmas of varying density and size. In particular, we show and explain the dependence of the angular distribution of the radiated photons on the transparency or opacity of the plasma. We then study the competition of the synchrotron and Bremsstrahlung emissions in copper foil targets irradiated by $10^{22}\,\rm W\,cm^{-2}$, $50 \, \rm fs$ laser pulses. Synchrotron emission is observed to be maximized for target thicknesses of a few $10 \, \rm nm$, close to the relativistic transparency threshold, and to be superseded by Bremsstrahlung in targets a few $μ$m thick. At their best efficiency, both mechanisms are found to radiate about one percent of the laser energy into photons with energies above $10\,\rm keV$. Their energy and angular spectra are thoroughly analyzed in light of the ultrafast target dynamics.
