Saroj K Majumdar
Articles written in Pramana – Journal of Physics
Volume 1 Issue 3 September 1973 pp 129-134 Plasmas
The kinetic equation and the equation of momentum transfer for a plasma
An attempt is made to derive a simple form of the collision integral of the kinetic equation for a plasma, by using Rostoker’s equation which expresses the pair correlation function in terms of the distribution functions of the particles, and the conditional probability of one particle shielding the other. The conditional probability function is assumed to be given by its equilibrium value. By taking first order velocity-moment of the resulting kinetic equation, the equation of momentum transfer has been obtained.
Volume 19 Issue 3 September 1982 pp 269-277 Plasma Physics
Nonlinear distribution functions for the Vlasov-Poisson system
The nonlinear distribution function introduced by Allis has been used to investigate the stability of the solution of Vlasov-Poisson’s equations. The ‘average’ Lagrangian is calculated on the basis of this distribution function, and the ‘average’ variational principle of Witham is applied to discuss modulational stability. It is found that the distribution function of Allis exactly gives rise to the Lighthill’s stability condition of non-linear waves.
Volume 23 Issue 6 December 1984 pp 785-801 Plasma Physics
Nonlinear distribution function for a plasma obeying Vlasov-Maxwell system of equations
The nonlinear distribution function of Allis, generalised to include the transverse electromagnetic waves in a plasma, is used to set up the coupled wave equations for the longitudinal and the transverse modes. These are solved, keeping terms up to the cubic order of nonlinearity, by using the method of multiple scales. The equations of wave modulation are derived, which are solved to discuss the nature of the modulational instability and solitary wave propagation. It is found that the solutions so obtained satisfy conditions which are very similar to the well known Lighthill criterion for stability, appropriately modified due to the coupling of the two modes. The role of the average constant current due to any flow of the resonant and trapped electrons in determining the stability, is also discussed.
Volume 96, 2022
All articles
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode
© 2021-2022 Indian Academy of Sciences, Bengaluru.