Loading...

Electron heating enhancement by frequency-chirped laser pulses

Yazdani, E ; Sharif University of Technology

1240 Viewed
  1. Type of Document: Article
  2. DOI: 10.1063/1.4894777
  3. Abstract:
  4. Propagation of a chirped laser pulse with a circular polarization through an uprising plasma density profile is studied by using 1D-3V particle-in-cell simulation. The laser penetration depth is increased in an overdense plasma compared to an unchirped pulse. The induced transparency due to the laser frequency chirp results in an enhanced heating of hot electrons as well as increased maximum longitudinal electrostatic field at the back side of the solid target, which is very essential in target normal sheath acceleration regime of proton acceleration. For an applied chirp parameter between 0.008 and 0.01, the maximum amount of the electrostatic field is improved by a factor of 2. Furthermore, it is noticed that for a chirped laser pulse with a0 = 5, because of increasing the plasma transparency length, the laser pulse can penetrate up to about ne ≈ 6nc, where nc is plasma critical density. It shows 63% increase in the effective critical density compared to the relativistic induced transparency regime for an unchirped condition
  5. Keywords:
  6. Electrostatics ; Hot electrons ; Ion beams ; Laser pulses ; Plasma density ; Transparency ; Chirped laser pulse ; Critical density ; Frequency chirped lasers ; Induced transparency ; Overdense plasma ; Particle-in-cell simulations ; Proton acceleration ; Target-normal sheath accelerations ; Plasma simulation
  7. Source: Journal of Applied Physics ; Vol. 116, issue. 10 , 2014
  8. URL: http://scitation.aip.org.ezp2.semantak.com/c