High laser field effects and laser-produced plasmas in a near QED regime

拟议的科学计划旨在探索接近量子电动力学（QED）效应强度阈值（约1023W/cm2）的激光产生的等离子体，该阈值现在可以通过新一代峰值功率超快激光器达到。申请人在瓦雷纳（Qc） INRS的先进激光光源（ALLS）设施将峰值功率激光器从200TW升级到750TW。这个新的基础设施已经准备就绪（2015年10月），具有更高的能量（高达12J）和更短的脉冲持续时间（16fs）。它将为实现接近1023W/cm2的目标强度和探索高场前沿科学提供前所未有的机会。新的ALLS基础设施和拟议的研究计划将帮助加拿大保持在极具竞争力和新颖科学的前沿。该计划包括两个与极高激光场与等离子体相互作用相关的主要方向，并被视为在QED状态下使用更高强度的更强大激光（多pw）进行更复杂实验的背景。

The proposed scientific program aims to explore laser-produced plasmas in a regime close to the Quantum Electrodynamics (QED) effects intensity threshold (around 1023W/cm2) that can now be reached with the new generation of high peak power ultrafast lasers. The applicant upgraded the high peak power laser, from 200TW to 750TW, at the Advanced Laser Light Source (ALLS) facility at INRS in Varennes (Qc). This new infrastructure is ready (October 2015) with higher energies (up to 12J) in shorter (16fs) pulse duration. It will provide an unprecedented opportunity to achieve intensities on target close to 1023W/cm2 and explore high field frontier science. The new ALLS infrastructure and the proposed research program will help to maintain Canada at the forefront of a very competitive and novel science. The proposed program includes two major directions related to the interaction of very high laser fields with plasmas and is seen as a background for more complex experiments with more powerful lasers (multi-PW) at higher intensities in the QED regime. The first sub-program aims to explore, in a controlled geometry, the effect of strong longitudinal oscillating electric fields on electrons in plasma. Such fields will be a key component in the complex strong field QED regime. We will study electron acceleration directly by the longitudinal field created by the tight focusing of the radially polarized (TM01 mode) 750TW beam. Electrons will be either produced and accelerated directly by the main laser pulse from mass limited targets positioned inside the focal spot or accelerated from a plasma preformed by a first beam and injected with appropriate delay in the focal volume. Scaling laws as a function of the laser pulse duration (down to near single cycle pulse) and of the focusing numerical aperture will be established to benchmark modeling. The second sub-program is on the generation and study of plasmas in a radiation-dominated regime. Hot dense matter heated to extreme temperature (specific energy densities >106MJ/kg) will be produced from extremely thin foils to study the unexplored regime of atomic physics in radiation-dominated regime and in regimes where very high E and B oscillating fields are key parameters. Atomic physics (ionization dynamics, equilibrium) and the generation and effect of short wavelength radiation (up to the gamma-ray range) will be studied with high-resolution X-ray spectroscopy. Plasmas dynamics will be probed on the femtosecond time scale using femtosecond betatron radiation to realize the first ever femtosecond time resolved X-ray absorption spectroscopy of