Particle-in-cell simulations of electron acceleration from relativistic interaction of mid-infrared laser interactions with near solid density matter
Abstract
Advances in ultra-intense laser technology are enabling, for the first time, relativistic intensities at mid-infrared (mid-IR) wavelengths. Anticipating further experimental research in this domain, we present high-resolution two dimensional Particle-in-Cell (PIC) simulation results using the Large-Scale Plasma (LSP) code that explores intense mid-IR laser interactions with near solid density targets. We present the results of thirty PIC simulations over a wide range of intensities (0.03<a0<40) and wavelengths (λ= 780 nm, 3 μm, and 10 μm). Earlier studies [Orban et al., Phys. Plasmas 22, 023110 (2015) and Ngirmang et al., Phys. Plasmas 23, 043111 (2016)], limited to λ= 780 nm and a0∼1, identified super-ponderomotive electron acceleration in the laser specular direction for normal-incidence laser interactions with dense targets. We extend this research to mid-IR wavelengths and find a more general result that normal-incidence super-ponderomotive electron acceleration occurs provided that the laser intensity is not highly relativistic (a0≲1) and that the pre-plasma scale length is similar to or longer than the laser wavelength. Under these conditions, ejected electron angular and energy distributions are similar to expectations from an analytic model used in Ngirmang et al. [Phys. Plasmas 23, 043111 (2016)]. We also find that, for a0∼1, the mid-IR simulations exhibit a classic ponderomotive steepening pattern with multiple peaks in the ion and electron density distribution. Experimental validation of this basic laser-plasma interaction process should be possible in the near future using mid-IR laser technology and optical interferometry.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 26, 2017
- Source ID
- 10.1063/1.4995669
Entities
People
- Chris Orban
- Enam Chowdhury
- Gregory K. Ngirmang
- John T. Morrison
- Scott Feister
- W. M. Roquemore
Organizations
- Air Force Office of Scientific Research
- Air Force Research Laboratory
- Ohio State University
- University of Chicago