Time-resolved measurements of fast electron recirculation for relativistically intense femtosecond scale laser-plasma interactions.

ABSTRACT: A key issue in realising the development of a number of applications of high-intensity lasers is the dynamics of the fast electrons produced and how to diagnose them. We report on measurements of fast electron transport in aluminium targets in the ultra-intense, short-pulse (<50?fs) regime using a high resolution temporally and spatially resolved optical probe. The measurements show a rapidly (?0.5c) expanding region of Ohmic heating at the rear of the target, driven by lateral transport of the fast electron population inside the target. Simulations demonstrate that a broad angular distribution of fast electrons on the order of 60° is required, in conjunction with extensive recirculation of the electron population, in order to drive such lateral transport. These results provide fundamental new insight into fast electron dynamics driven by ultra-short laser pulses, which is an important regime for the development of laser-based radiation and particle sources.

SUBMITTER: Green JS 

PROVIDER: S-EPMC5852165 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature