Modeling of flowing magnetized plasma for small volume plasma system

Flowing magnetised plasmas is crucial for applications in semiconductor device manufacturing, materials processing, plasma propulsion etc. In these cases, plasma moves along magnetic field lines from the source to an expansion chamber or into space. In this context, Plasma Lab, IIT Delhi has developed and patented the Compact ECR Plasma Source (CEPS) [1,4] to study plasma expansion in various chamber sizes [1-4]. Notably, its integration with the Small Volume Plasma System (SVPS) revealed key results like isothermal electrons obeying double adiabatic behavior, and n/B scaling of the bulk plasma.



Motivated by the cited experiments [1-4] the authors developed a flow model for a magnetized plasma with a view to investigate the flow dynamics of the SVPS experiments. The experimental conditions of the SVPS require the model to describe a stationary, collisional, quasineutral, axisymmetric plasma. Additionally, the ions are cold while the electrons are isothermal and in thermal equilibrium, obeying the Boltzmann relation. In a plasma flowing along a magnetic field, the velocity of ions along the magnetic field lines is much greater than the velocity perpendicular to the field. The latter fact offers scope for a unique ordering of the the relevant variables by transforming the flow equations to the magnetic coordinate system (MCS) with coordinate axes parallel and perpendicular to the field lines. The ordering of the flow variables in the MCS, permits further ordering and simplification of the flow equations. These reduced flow equations are solved on a magnetic coordinate grid, using the SVPS experimental data to initialise the equations along the different magnetic coordinate axes. The obtained numerical results compare favourably with the SVPS observations and will be presented at the conference.

[1] Ganguli, A., et al. 2013 19th IEEE Pulsed Power Conference (PPC). IEEE, 2013.

[2] Ganguli, A., et al. Plasma Sources Science and Technology 25.2 (2016): 025026.

[3] Ganguli, A., et al. Plasma Sources Science and Technology 28.3 (2019): 035014.

[4] Verma, Anshu, et al. Proc. 4th Asia Pacific Conf. Plasma Phys. 2020.