Parametric excitation of surface plasma waves by stimulated Compton scattering of laser beam at metal-free space interface. (27th June 2016)

• Record Type: Journal Article
• Authors: Goel, D.; Chauhan, P.; Varshney, A.; Sajal, V.
• Is Part Of: Laser and particle beams. Volume 34:Number 3(2016)
• Page Start: 467
• Page End: 473
• Publication Date: 2016-06-27
• Subjects: Surface plasma waves, -- Parametric excitation, -- Stimulated Compton scattering; Laser beams -- Periodicals; Particle beams -- Periodicals; 535.5
• DOI: 10.1017/S0263034616000343
• Languages: English
• ISSNs: 0263-0346

Abstract

Abstract: An obliquely incident high-power laser (ω0, k 0 z ) on the metallic surface can resonantly excite a surface plasma wave (SPW) (ω1, k 1 z ) and a quasi-electrostatic plasma wave (ω, k z ) inside the skin layer at the phase-matching conditions of frequency ω1 = ω − ω0 and wave number k 1 z = k z − k 0 z . The oscillating electrons in the skin layer couples with the seed SPW and exert non-linear ponderomotive force on electrons at the frequency of quasi-static mode. Density perturbations due to quasi-static mode and ponderomotive force associate with the motion of electrons (due to incident laser) and give rise to a non-linear current by feedback mechanism. At ω/ k z ~ v F (where v F is the Fermi velocity of metal) this non-linear current is responsible for the growth of SPW. The maximum growth of the present process (≅1.5 × 10 12 s −1 ) is achieved at incident angle θ = 42° for laser frequency ω0 = 2 × 10 15 rad/s. Growth of SPW enhances from 1.62 × 10 11 to ≅1.5 × 10 12 s −1 as the magnetic field changes from 12 to 24 MG. The excited SPW can be utilized for surface heating and diagnostics purpose.