Continuation of Full-Scale Three-Dimensional Numerical Experiments on High-Intensity Particle and Laser Beam-Matter Interactions

这项研究的目标主要是促进对强激光和粒子束在等离子体中传播时发生的复杂相互作用的理解。非常精确的模拟被用来研究这些相互作用，重点是为新型超紧凑粒子加速器开发具体的概念。粒子加速器是用于科学发现的最复杂和最昂贵的工具之一。它们被用来发现自然界中最基本的粒子，了解生物学的基本过程，探索和开发材料，以及治疗癌症。等离子体是一种由带电粒子组成的电离气体，有时被称为物质的第四态。当非常明亮的光的短脉冲或强电子的短脉冲通过等离子体时，就会产生尾迹或波。尾迹中的波峰和波谷以接近光速的速度移动，带电粒子随后可以冲浪，也可以加速到接近光速的速度。这项研究将集中于了解如何控制激光与等离子体的相互作用以产生等离子体尾迹并将注入的光束加速到非常高的能量。研究将使用精确模拟和理论相结合的方法来促进对强激光和粒子束等离子体相互作用领域的基础高能量密度科学的理解，以及如何利用等离子体波尾迹来操纵粒子束的六维相空间。这将包括产生奇异和明亮的光束，以及有效地加速正电子。这项研究依赖于胞内粒子方法，该方法模拟了等离子体中单个电子和离子通过其自洽产生的电场和磁场以及任何外部磁场相互作用时的轨迹。这项以发现为导向的研究还将有助于提供所需的理解，以开发用于高能物理对撞机、下一代光源、医学和国土安全的等离子体加速器级。这项工作将基础研究和发现驱动的研究与细胞内粒子模拟相结合，包括当前、近期和长期实验的全尺寸3D建模。这些模拟一再被证明为理论想法和新概念提供了一个试验台，并为指导正在进行的和未来的实验提供了一种方法。这项研究继续包括针对诊断良好的实验和彼此之间的基准代码。使用美国最大的计算机进行的高保真全尺寸建模提供了一种方法，可以将参数外推到未来几年内无法进行实验的区域。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The goal of this research is broadly aimed at advancing the understanding of the complex interactions that occur when intense lasers and particle beams propagate through plasmas. Very accurate simulations are used to study these interactions, focusing on developing concrete concepts for new classes of ultra-compact particle accelerators. Particle accelerators are some of the most complex and expensive tools used for scientific discovery. They are used to discover the most fundamental particles in nature, to understand fundamental processes in biology, to probe and develop materials, and to treat cancer. A plasma, an ionized gas of charged particles, is sometimes called the fourth state of matter. When a short pulse of very bright light or a short pulse of a high current of electrons are sent through a plasma a wake or wave is created. The crests and troughs in this wake move near the speed of light, and charged particles can then surf this wake and also accelerate to near the speed of light. This research will focus on understanding how the laser-plasma interactions can be controlled to lead to the creation of the plasma wake and the acceleration of the injected beam to very high energies.The research will use a combination of accurate simulations and theory to advance the understanding of basic high-energy density science in the area of intense laser and particle beam plasma interactions, and on how to manipulate the six dimensional phase space of particle beams using plasma wave wakefields. This will include production of exotic and bright beams, and efficient acceleration of positrons. This research relies on the particle-in-cell method which simulates the trajectories of individual electrons and ions in the plasma as they interact through their self-consistently generated electric and magnetic fields and any externally applied fields. This discovery driven research will also help to provide the understanding needed to develop plasma-based accelerator stages for use in high energy physics colliders, next-generation light sources, medicine, and homeland security. This effort blends basic and discovery driven research with particle-in-cell simulations including full-scale 3D modeling of current, near term, and far term experiments. The simulations have repeatedly been shown to provide a test bed for theoretical ideas and new concepts and a method for guiding ongoing and future experiments. The research continues to include benchmarking codes against well-diagnosed experiments and each other. High-fidelity full-scale modeling using the nations largest computers provides a means to extrapolate parameters into regimes that will not be accessible to experiments for years to come.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.