Author: Jovanovic, I.
Paper Title Page
WEPZ010 Modeling and Experimental Update on Direct Laser Acceleration 2787
 
  • I. Jovanovic, M.W. Lin
    Penn State University, University Park, Pennsylvania, USA
 
  Funding: This work is supported by the Defense Threat Reduction Agency under contract HDTRA1-11-1-0009.
Moderate-energy, high-repetition-rate electron beams are needed in a variety of applications such as those in security and medicine, while requiring that the acceleration be realized in a compact and relatively inexpensive package. Laser wakefield acceleration is an attractive technology which meets most of those requirements, but it requires the use of relatively high peak power lasers which do not scale readily to high repetition rates. We are developing the theoretical and experimental basis for advancing the science and technology of direct laser acceleration (DLA) of charged particles using the axial component of the electric field of a radially polarized intense laser pulse. DLA is an acceleration method which exhibits no threshold and is thus compatible with the use of lower peak power, but much higher repetition rate lasers. We are currently numerically investigating the conditions for quasi-phase-matched DLA of electrons in plasma waveguides and experimentally implementing the quasi-phase-matched waveguide structure in laser-produced plasmas.
 
 
THPS062 Cavity-recirculated Laser Charge Stripping of Hydrogen Ions 3568
 
  • I. Jovanovic
    Penn State University, University Park, Pennsylvania, USA
  • R. Tikhoplav
    RadiaBeam, Santa Monica, USA
 
  Funding: This work is supported by the U.S. Department of Energy.
High-intensity proton accelerators such as those at the Oak Ridge National Laboratory’s Spallation Neutron Source require an intense, robust, reliable, and low-cost source of hydrogen ions. Laser-based charge stripping is a promising, high-efficiency method that could meet the requirements of present and future facilities. We are seeking to improve the efficiency of hydrogen ion stripping by an order of magnitude using laser recirculation. In our approach we recirculate a high-power laser using the technique termed recirculation injection by nonlinear gating, with a frequency-doubling nonlinear crystal as an efficient switch that allow pulse injection into the cavity. We present our progress on cavity development and the preliminary experimental assessment of cavity performance in high-radiation environment. Our experimental studies were conducted by irradiating the nonlinear crystal used in the laser cavity by fast neutrons in a research nuclear reactor and measuring its change in transmissivity.