Experimental Study of Nanosecond Laser-Generated Plasma Channels

• Main Authors: Tadzio Levato, Michal Nevrkla, Muhammad Fahad Nawaz, Lorenzo Giuffrida, Filip Grepl, Haris Zulic, Jan Pilar, Martin Hanus, Martin Divoky, Antonio Lucianetti, Tomas Mocek, Daniele Margarone
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Applied Sciences
• Subjects: LWFA; plasma guiding; nanosecond laser; laser-plasma acceleration
• Online Access: https://www.mdpi.com/2076-3417/10/12/4082

Generation of plasma-channels by interaction of gas targets with nanosecond laser beams was investigated experimentally. Such laser-generated plasma channels are very promising for subsequent guiding of high peak power femtosecond laser pulses, over several tens of centimeters, as required in laser wake field electron-acceleration (LWFA). The experimental setup was based on the use of a cylindrical lens (100 mm of focal length) with the aim of proposing a technical solution easy to be integrated into a compact experimental setup for acceleration of multi-GeV electron beams using high peak-power laser systems. A pilot experiment, showing production of asymmetric plasma channels over a length of several millimeters in N and Ar targets with initial neutral-gas atomic density around 5 × 10¹⁹ cm⁻³, is reported. Plasma effective threshold formation was estimated, along with future optimization of the optical setup for a symmetrization of such plasma channel. Scalability of this concept to several tens of centimeters is preliminarily discussed, along with the corresponding critical requirements for an optimal LWFA scheme.