Theoretical and numerical investigation of the advanced acceleration concepts in the field of intense laser plasma interaction

Abstract

The thesis focuses on the acceleration principles in the field of nonlinear interaction newlineof an ultrashort, ultra-intense electromagnetic (EM) pulse with ultrathin solid dense newlinetarget in the radiation pressure dominant (RPD) regime. This interaction newlineinstantaneously transforms dense solid foil into over dense plasma. An incident laser newlinepulse accelerates the entire plasma foil and the plasma dynamics becomes newlinerelativistic. At the intensities I and#61502;1022W cm2 , the radiation pressure approaches tens newlineof tera bar which makes the plasma electrons pushed away and the ions are dragged newlineby the intense electrostatic field by almost the same velocity as that of electrons. newlineOwing to ponderomotive force of the ultra-intense laser, the ions are accelerated newlineacquiring energy in the range of the order of GeV. The most efficient way to transfer newlineenergy and momentum to charged particles is through radiation pressure. Ions newlineaccelerated in the RPD regime are characterized by being almost monoenergetic and newlinehigh efficiency of the energy conversion from laser to the plasma. newlineWe have computed ion momentum/energy along with their corresponding newlinenumbers. The efficiency and the other parameters are also obtained for various newlinepulses, namely, Gaussian, Lorentzian, and Hyperbolic secant. The Hyperbolic secant newlinepulse is more efficient in delivering more energy to the ions than that of the newlineLorentzian pulse. Suitably tailoring laser pulse results in stabilizing the laser newlineacceleration of ions via the radiation pressure acceleration (RPA) process and the newlineenergy and momentum transference to ions becomes more effective. newlineFurther, the interaction of ultra-thin solid target and a laser pulse with newlinetransversely inhomogeneity leads to the plasma foil expansion in transverse direction newlineresulting in the decrease in the number of ions that will be accelerated longitudinally newlineand thus enhancement of laser energy imparted per ion in the target. We addressed newlinethe effect of the group velocity of the laser while analysing the intense laser-plasma newlineinteraction.