Collisional Radiative Model For Plasma Modelling

Abstract

Plasma spectroscopy techniques are the key diagnostics to study the physical properties of various type of plasmas. In plasma spectroscopy, several spectroscopic models have been proposed, like the Thermodynamic Equilibrium (TE) model, the Local Thermodynamic Equilibrium (LTE) model, the Coronal model and the Collisional Radiative (CR) model. The TE model is based on detailed balanced atomic processes where the rate of each and every process is exactly balanced by the rate of its inverse process. But usually, we can't get this type of detailed balance in a laboratory plasma. So the TE model couldn't explain clearly the plasma properties. After the TE model, the LTE model has been proposed, which mainly considers the collision processes but can't take the radiative processes into account. So, this model unable to explain all plasma properties completely. The Collisional Radiative model has been proposed to overcome these problems, considering both the collisional and radiative processes into account. Population models describe the dependence of the population densities of the excited molecular or atomic states in plasma on various plasma parameters, like electron density and temperature. Here, in my project report, we are going to discuss a brief introduction to the plasma models. Then mainly we will discuss the CR model with the help of kinetic code FLYCHK. Collisional Radiative models are based on detailed atomic structures (e.g. fine structure levels). They are able to demonstrate good quality atomic data and good agreement with highly resolved experimental data. The CR models is applicable even to non-equilibrium plasmas with a wide range of electron density and temperature.