International EMMI Workshop on Plasma Physics at FAIR, GSI Darmstadt, June 21 - 23, 2017

As the laser technology continues its spectacular development, ever higher field intensities and power levels become accessible in laboratories. This opens new horizons for laser applications in ultra-bright sources of short wavelength radiation. At the same time, the laser pulse quality – like the contrast ratio – is greatly improved so that fine structured targets maintain their structure till the main pulse arrival. This opens new and unexpected possibilities for laser-plasma engineering towards new physics. In the talk, we consider laser pulse interaction with nano- and micro-structured targets like nano-grass or microchannels [1,2] in the intensity range 10 18 -10 20 W/cm 2 . At intensities higher than 10 22 W/cm 2 , the radiation damping force becomes important and can exceed the Lorentz force acting on an electron [2]. The gamma-ray emission is then the major channel of laser energy absorption [3,4]. When a micro-plasma waveguide (MPW) is coupled with a readily available 2J laser, it may serve as a novel compact x-ray source. Electrons are extracted from the walls and form a dense helical bunch inside the channel. These electrons are efficiently accelerated and wiggled by the waveguide modes in the MPW, which results in a bright, well-collimated emission of hard x rays in the range of 1 ∼ 100 keV [5]. References: 1. MA Purvis, VN Shlyaptsev, R Hollinger, C Bargsten, A Pukhov, et al. Nature Photonics 7, 796 (2013) 2. LL Ji, A Pukhov, IY Kostyukov, BF Shen, K Akli Physical review letters 112, 145003 (2014) 3. LL Ji, A Pukhov, EN Nerush, IY Kostyukov, BF Shen, KU Akli Physics of Plasmas 21, 023109 (2014) 4. Longqing Yi, Alexander Pukhov, Phuc Luu-Thanh, and Baifei Shen, Phys. Rev. Lett. 116, 115001 (2016)