论文标题
使用复合抛物线浓缩剂在近相关强度下激光目标耦合的数量级增加
Order of magnitude increase in laser-target coupling at near-relativistic intensities using compound parabolic concentrators
论文作者
论文摘要
将高转化效率达到相对论电子是短脉冲激光应用的核心，并且从根本上依赖于创建具有强度$ {\ gg} 10^{18} $ 〜w/cm $ $^2 $的交互区域。通常使用小焦距光学器件来实现此目标；但是，对于受设施几何形状，碎片关注和组件成本限制的大型KJ级系统，该解决方案是不切实际的。我们将目标安装的化合物抛物线浓缩器列出了以克服这些局限性，并且与平坦目标相比，转化效率的数量级几乎增加了，并且电子温度的三倍超过三倍。粒子中的粒子模拟表明，从锥壁反射中发展的锥体内的血浆限制和湍流激光场的形成是造成改进的激光对靶向耦合的原因。 {这些被动目标组件可用于提高所有高强度短脉冲激光应用的耦合效率，尤其是在具有较长焦距光学元件的大型设施中。
Achieving a high conversion efficiency into relativistic electrons is central to short-pulse laser application and fundamentally relies on creating interaction regions with intensities ${\gg}10^{18}$~W/cm$^2$. Small focal length optics are typically employed to achieve this goal; however, this solution is impractical for large kJ-class systems that are constrained by facility geometry, debris concerns, and component costs. We fielded target-mounted compound parabolic concentrators to overcome these limitations and achieved nearly an order of magnitude increase to the conversion efficiency and more than tripled electron temperature compared to flat targets. Particle-in-cell simulations demonstrate that plasma confinement within the cone and formation of turbulent laser fields that develop from cone wall reflections are responsible for the improved laser-to-target coupling. {These passive target components can be used to improve the coupling efficiency for all high-intensity short-pulse laser applications, particularly at large facilities with long focal length optics.
