**Abstract**

**THEORETICAL STUDY OF MAGNETIC FIELD GENERATION DUE TO PONDEROMOTIVE FORCE IN PLASMA.**

#### Kiran Adhikari (Golden Gate International College ( Tribhuvan Univ)

In this dissertation work the phenomenon of ponderomotive force and laser interaction in plasma have been studied. For this, we start from the general expression for the force density (i.e the equation of the motion ) of plasma in the electromagnetic field have been derived on the basis of Maxwell equation. The equation of the motion is deduced not only from the ponderomotive force but also from the theory of two fluid model. We take 𝜈 =0 (collisionless plasma) because the relation of the equation which is valid when the fast oscillation properties are neglected .The complete equation of the motion can be deduced from the basic equation of the continuum mechanics in relativistic formulation used in the well known theory of radiation frequencies. In the presence of intense laser light, plasma particle are entrained by the fields of light and hence induced current, which in turn generate magnetic field. The recent work shows that larger order of mega gauss magnetic field is governed by scale length and intensity of light used. From this work we had seen that ponderomotive force arise due to the interaction of drifting electrons produced by the electric vector of the wave with magnetic vector 𝐵 of the wave and due to the gradient of the drift velocity. For the theoretical calculation of B field in plasma we have taken exponential variation in electron density along the axial direction and the Gaussian pulse which has intensity distribution along the radial direction only.

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