Transition from Coherent to Stochastic electron heating in ultrashort relativistic laser interaction with structured targets.
Transition from Coherent to Stochastic electron heating in ultrashort relativistic laser interaction with structured targets.
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DOI：
10.1038/s41598-017-01677-5
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发表时间：
2017-05-03
影响因子：
4.6
通讯作者：
Gizzi LA
中科院分区：
文献类型：
--
作者：
Cristoforetti G;Londrillo P;Singh PK;Baffigi F;D'Arrigo G;Lad AD;Milazzo RG;Adak A;Shaikh M;Sarkar D;Chatterjee G;Jha J;Krishnamurthy M;Kumar GR;Gizzi LA
相对论激光与微米和纳米尺度表面结构的相互作用增强了向固体靶的能量传递，并在极端条件下产生物质。我们报告的比较研究的激光与目标的相互作用机制与不同尺寸的线结构，揭示了从相干粒子加热到随机等离子体加热制度时发生的迁移从微米尺度到纳米尺度的线。实验和动力学模拟表明，线之间的大间隙有利于通过激光加速到通道中产生高能电子，而小于激光场中电子振荡幅度的间隙导致能量较低的电子和多keV等离子体产生，与先前发表的实验一致。由于超短脉冲典型的皮秒基座，纳米尺寸间隙的等离子体填充强烈影响与此类目标的相互作用，将激光穿透深度降低至约一百纳米。这两个加热制度似乎分别适用于激光驱动的离子/电子加速计划和温暖的致密物质的调查。
Relativistic laser interaction with micro- and nano-scale surface structures enhances energy transfer to solid targets and yields matter in extreme conditions. We report on the comparative study of laser-target interaction mechanisms with wire-structures of different size, revealing a transition from a coherent particle heating to a stochastic plasma heating regime which occurs when migrating from micro-scale to nano-scale wires. Experiments and kinetic simulations show that large gaps between the wires favour the generation of high-energy electrons via laser acceleration into the channels while gaps smaller than the amplitude of electron quivering in the laser field lead to less energetic electrons and multi-keV plasma generation, in agreement with previously published experiments. Plasma filling of nano-sized gaps due to picosecond pedestal typical of ultrashort pulses strongly affects the interaction with this class of targets reducing the laser penetration depth to approximately one hundred nanometers. The two heating regimes appear potentially suitable for laser-driven ion/electron acceleration schemes and warm dense matter investigation respectively.