An intense laser pulse propagating through a near-critical density plasma is capable of generating a high peak current electron beam (~100kA) by means of a laser wakefield operating in the bubble regime. This beam drives surface currents on the sheath of the cavitation that produces large azithumal magnetic fields (~100 MG) and induces an on-axis electron current. These effects lead to a Z-pinch of the ambient plasma ions. Eventually the field confining the pinch relaxes and the ions explode radially due to self-repulsive forces. If this process occurs at a sharp exit gradient, the ions acquire some forward momentum consistent with the magnetic vortex acceleration mechanism. Fully 3D simulations indicate that the highest energy ions are emitted conically with a secondary lower energy ion beam accelerated on the axis.

Date Published: 14 May 2015
PDF: 7 pages
Proc. SPIE 9514, Laser Acceleration of Electrons, Protons, and Ions III; and Medical Applications of Laser-Generated Beams of Particles III, 951409 (14 May 2015); doi: 10.1117/12.2178878

Published in SPIE Proceedings Vol. 9514:
Laser Acceleration of Electrons, Protons, and Ions III; and Medical Applications of Laser-Generated Beams of Particles III
Kenneth W. D. Ledingham; Eric Esarey; Carl B. Schroeder; Klaus Spohr; Paul McKenna; Florian J. Grüner; Paul R. Bolton, Editor(s)