Forward Ion Acceleration in Thin Films Driven by a High-Intensity Laser

Authors

Anatoly Maksimchuk, University of MichiganFollow
S. Gu, University of Michigan, Ann Arbor
K. Flippo, University of Michigan, Ann Arbor
Donald P. Umstadter, University of Nebraska-LincolnFollow
V. Yu. Bychenkov, Institute of Laser Engineering, Osaka University, Japan

Date of this Version

5-1-2000

Comments

Published by American Physical Society. Physical Review Letters 84, 4108 (2000). http://prl.aps.org. Copyright © 2000 American Physical Society. Permission to use.

Abstract

A collimated beam of fast protons, with energies as high as 1.5 MeV and total number of ≳10⁹, confined in a cone angle of 40°±10° is observed when a high-intensity high-contrast subpicosecond laser pulse is focused onto a thin foil target. The protons, which appear to originate from impurities on the front side of the target, are accelerated over a region extending into the target and exit out the back side in a direction normal to the target surface. Acceleration field gradients ∼10 GeV/cm are inferred. The maximum proton energy can be explained by the charge-separation electrostatic-field acceleration due to “vacuum heating.”