Analysis of the Angular Distribution of Emission of Neutrons Generated with the Ponderomotive Mechanism of Ion Heating by High-Power Short Laser Pulse Acting on a (CD2)n Target

The crossed-beam energy transfer model without empirical factor for multi-beam irradiation of a spherical laser target

“…First, consider the threewave interaction. Since density perturbations with k ar ≫ k an are taken into account, the change in the intensities of incident q 0 and scattered q 1 waves without taking into account absorption is described by the equations [1]:…”

“…where k = ω/c is the laser wave number, β = √ ε, ρ 0 is the undisturbed plasma density, µ is the ion viscosity coefficient, c s = [(ZT e + T i )/m i ] 1/2 is the sound velocity. Equations ( 2)-( 4) describe the interaction of waves q 0 and q 1 with a perturbation of the plasma density, which occurs under the action of ponderomotive force [1]. In this case, the incoming wave q 0 , directed against the radius, weakens with a decrease in r. The outgoing wave q 1 , directed along the radius, increases with the growth of r. The coefficient B in ( 2) and (3) has a resonant dependence in the vicinity of the point M = 1.…”

“…Stimulated scattering prevents the passage of laser radiation into a denser plasma, where the absorption coefficient is higher. In an expanding laser plasma with a normal incidence of radiation, stimulated scattering occurs when two counter-propagating electromagnetic waves interact with an acoustic wave (three-wave interaction) [1]. At the same time, the electromagnetic wave entering the plasma is weakened, and the outgoing wave is amplified.…”

“…The maxima of the field amplitude can move in space if the wave frequencies ω 0 and ω 1 are different. You can always use a new coordinate system in which the wave frequencies ω ′ 0 and ω ′ 1 will be the same [1]. The plasma velocity u ′ in the new system will change.…”