Plasma wave aided heating of collisional nanocluster plasma by nonlinear interaction of two high power laser beams

In this theoretical investigation, plasma wave aided heating scheme is analytically studied in collisional nanocluster plasma by two high power Hermite cosh-Gaussian laser beams. Due to the interaction of laser beams with plasma embedded nanocluster, the cluster gets ionize and become into plasma plume ball. Nonlinear interaction of two laser beams causes the beat wave with frequency ω=ω1-ω2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\omega = \omega_{1} - \omega_{2}$$\end{document} and beat wave number k=k1-k2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k = k_{1} - k_{2}$$\end{document} in plasma embedded with clusters. The oscillatory velocities due to each laser beam produce the nonlinear ponderomotive force. This nonlinear force might have much potential to excite the plasma wave and lead the electron heating. Analytic expressions of anomalous heating rate and evolution of electron temperature are derived. The heating rate is found maximum at laser normalized transverse propagation distance from y-axis y/w0∼0.4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$y/w_{0} \sim 0.4$$\end{document}. It is observed that anomalous heating rate is resonantly increased by the presence of surface plasmon oscillations. This extreme condition of heating rate is achieved when laser beat wave frequency is comparatively near the frequency of surface charge oscillations of nanoclustered plasma and is typically ω∼ωpe/3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\omega \sim \omega_{pe} /\sqrt 3$$\end{document}. The graphical discussion of this theory promises that heating rate can be effectively enhanced by varying the beam decentred parameter, beam width, mode index, rippled clustered density, clustered radius, and collisional frequency. It is also analysed that laser beam decentred parameter plays a sensitive role on nanocluster heating. By generalizing this laser heating theory, soft X-ray emission can be achieved via Bremsstrahlung process.