论文标题
量子对辐射摩擦驱动磁场产生的影响
Quantum effects on radiation friction driven magnetic field generation
论文作者
论文摘要
大而圆周极化激光脉冲与高密度等离子体的相互作用中的辐射损失可以通过吸收光子角动量（所谓的Faraday效应），从而导致强大的准磁场的产生。为了实现几种吉加高斯激光强度的磁场强度，需要$ \ simeq 10^{24} $ w/cm $^2 $，这将使经典和量子制度之间的边界相互作用。我们通过使用修饰的辐射摩擦力来改善“孔钻孔”状态中激光相互作用与过度临界等离子体的经典建模，该摩擦力占高能下量子后坐力和光谱截止的情况。分析计算和三维粒子中模拟的结果表明，在可预见的情况下，量子效应可能导致激光辐射转化率降低到高能光子向高能光子的降低。相应地抑制了磁场振幅，并在磁场能量中抑制了多个级数。该量子抑制显示在一定的强度值时达到最大值，并且不会随着强度的进一步增加而生长。量子抑制因子的非单调行为是由纵向血浆加速度和辐射反应力的关节作用引起的。预测的功能可以作为辐射摩擦理论的合适诊断。
Radiation losses in the interaction of superintense circularly polarized laser pulses with high-density plasmas can lead to the generation of strong quasistatic magnetic fields via absorption of the photon angular momentum (so called inverse Faraday effect). To achieve the magnetic field strength of several Giga Gauss laser intensities $\simeq 10^{24}$W/cm$^2$ are required which brings the interaction to the border between the classical and the quantum regimes. We improve the classical modeling of the laser interaction with overcritical plasma in the "hole boring" regime by using a modified radiation friction force accounting for quantum recoil and spectral cut-off at high energies. The results of analytical calculations and three-dimensional particle-in-cell simulations show that, in foreseeable scenarios, the quantum effects may lead to a decrease of the conversion rate of laser radiation into high-energy photons by a factor 2-3. The magnetic field amplitude is suppressed accordingly, and the magnetic field energy - by more than one order in magnitude. This quantum suppression is shown to reach a maximum at a certain value of intensity, and does not grow with the further increase of intensities. The non monotonic behavior of the quantum suppression factor results from the joint effect of the longitudinal plasma acceleration and the radiation reaction force. The predicted features could serve as a suitable diagnostic for radiation friction theories.
