Stable, tunable, quasimonoenergetic electron beams produced in a laser wakefield near the threshold for self-injection

Authors

• Sudeep Banerjee, University of Nebraska-LincolnFollow
• Serguei Y. Kalmykov, University of Nebraska-LincolnFollow
• Nathan D. Powers, University of Nebraska-LincolnFollow
• Grigory V. Golovin, University of Nebraska-LincolnFollow
• Viswanathan Ramanathan, Rensselaer Polytechnic Institute
• Nathaniel J. Cunningham, Nebraska Wesleyan UniversityFollow
• Kevin J. Brown, University of Nebraska-LincolnFollow
• Shouyuan Chen, University of Nebraska - LincolnFollow
• Isaac A. Ghebregziabher, University of Nebraska - LincolnFollow
• Bradley Allan Shadwick, University of Nebraska-LincolnFollow
• Donald Umstadter, University of Nebraska-LincolnFollow
• B. M. Cowan, Tech-X Corporation, Boulder, CO
• D. Bruhwiler, University of Colorado at Boulder
• A. Beck, CEA, DAM, DIF, Arpajon Cedex, France
• E. Lefebvre, CEA, DAM, DIF, Arpajon Cedex, France

Document Type

Article

Date of this Version

2013

Citation

Phys. Rev. ST Accel Beams 16, 031302 (2013).

DOI: 10.1103/PhysRevSTAB.16.031302

Comments

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License.

Abstract

Stable operation of a laser-plasma accelerator near the threshold for electron self-injection in the blowout regime has been demonstrated with 25–60 TW, 30 fs laser pulses focused into a 3–4 millimeter length gas jet. Nearly Gaussian shape and high nanosecond contrast of the focused pulse appear to be critically important for controllable, tunable generation of 250–430 MeV electron bunches with a low-energy spread, ∼10  pC charge, a few-mrad divergence and pointing stability, and a vanishingly small low-energy background. The physical nature of the near-threshold behavior is examined using three-dimensional particle-in-cell simulations. Simulations indicate that properly locating the nonlinear focus of the laser pulse within the plasma suppresses continuous injection, thus reducing the low-energy tail of the electron beam.