Dynamics of the interaction of relativistic Laguerre-Gaussian laser pulses with a wire target
Dynamics of the interaction of relativistic Laguerre-Gaussian laser pulses with a wire target
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相对论拉盖尔-高斯激光脉冲与线目标相互作用的动力学
DOI：
10.1088/1361-6587/aaefb6
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发表时间：
2019
影响因子：
2.2
通讯作者：
Shao Fu Qiu
中科院分区：
文献类型：
--
作者：
Hu Li Xiang;Yu Tong Pu;Lu Yu;Zhang Guo Bo;Zou De Bin;Zhang Hao;Ge Zhe Yi;Yin Yan;Shao Fu Qiu
采用三维粒子模拟方法，研究了超强拉盖尔-高斯（LG）激光脉冲与金属丝靶相互作用的动力学过程。当相对论LG模激光脉冲扫过金属丝靶时，具有阿秒持续时间的环形电子束团被周期性地拖出金属丝的左尖端。由于径向激光电场力作用于电子，环形聚束被紧紧地约束在靶面附近，并沿着导线稳定地传播。因此，诱导强返回电流以满足等离子体中和条件。一旦离开靶的右尖端，电子发射角逐渐减小，并且每个空心电子聚束被会聚成电子盘。在纵向电场的作用下，电子被不断加速到100 s MeV。同时，激光的角动量被有效地转移到聚束的光束角动量（BAM）。密集短电子束团的结构稳定，在300 fs以上保持完整。我们可以通过改变激光和靶的参数，如激光的旋向性和强度、束腰半径、金属丝的长度和半径来控制聚束的质量。该方案为获得具有低发散角、高束流电荷和大BAM的高质量阿秒电子聚束团奠定了基础，具有广泛的应用前景。
By using three-dimensional particle-in-cell simulations, we investigate the dynamics of ultraintense Laguerre–Gaussian (LG) laser pulses interacting with a wire target. When a relativistic LG-mode laser pulse sweeps a wire target, annular electron bunches with attosecond duration are periodically dragged out of the left tip of the wire. Due to the radial laser electric field force exerted on the electrons, the annular bunches are tightly constrained near the target surface and steadily propagate along the wire. A strong return current is thus induced to satisfy the plasma neutralization condition. Once leaving from the right tip of the target, the electron emission angle gradually decreases and each hollow electron bunch is converged into an electron disc. Under the action of the longitudinal electric field, electrons are continuously accelerated to 100s MeV. At the same time, the laser angular momentum is transferred efficiently to the beam angular momentum (BAM) of the bunches. The structure of the dense short electron bunches is stable and keeps intact for more than 300 fs. We can manipulate the quality of the bunches by changing the laser and target parameters, such as the laser handedness and intensity, beam waist radius, wire length and radius. The scheme paves the way for the generation of high-quality attosecond electron bunches with low divergence, high beam charge and large BAM, which will have wide-range applications in various domains.