Ultraintense Laser-Produced Fast-Electron Propagation in Gas Jets

D. Batani (1) , S. Baton (2) , M. Manclossi (1) , J. J. Santos (2) , François Amiranoff (2) , M. Koenig (2) , Emanuele Martinolli (1, 2) , A. Antonicci (1) , C. Rousseaux (3) , M. Rabec Le Gloahec (3) , T. Hall (4) , Victor Malka (5) , T.E. Cowan (6) , J. King (7) , R. R. Freeman (7) , M. Key (8) , S. Stephens (9)

1 Dipartimento di Fisica "Giuseppe Occhialini" = Department of Physics "Giuseppe Occhialini" [Milano-Bicocca]
2 LULI - Laboratoire pour l'utilisation des lasers intenses
3 DAM/DIF - DAM Île-de-France
4 University of Essex
5 LOA - Laboratoire d'optique appliquée
6 UNR - Physics Department, MS-220
7 UCD - Department of Applied Sciences
8 LLNL - Lawrence Livermore National Laboratory
9 Inertial Fusion Technology Division

We study the propagation of fast electrons in a gas at different densities. A large relativistic electron current is produced by focusing a short-pulse ultrahigh-intensity laser on a metallic target. It then propagates in a gas jet placed behind the foil. Shadowgraphy in the gas shows an electron cloud moving at sub-relativistic average velocities. The experiment shows (i) the essential role of the density of background material for allowing propagation of fast electrons, (ii) the importance of the ionization phase which produces free electrons available for the return current, and (iii) the effect of electrostatic fields on fast-electron propagation.

Domains: Physics [physics]; Physics [physics]; Optics [physics.optics]

D. Batani, S. Baton, M. Manclossi, J. J. Santos, François Amiranoff, et al.. Ultraintense Laser-Produced Fast-Electron Propagation in Gas Jets. Physical Review Letters, 2005, 94 (5), pp.055004. ⟨10.1103/PhysRevLett.94.055004⟩. ⟨hal-00508728⟩