The Balmer-line-ratio method to predict electron temperature using Collisional Radiative model for Hydrogen plasma in PFRC-II*

A collisional-radiative (CR) model [1-4] to extract the electron temperature of hydrogen plasmas from Balmer-line ratio measurements has been developed. The forward component of the model computes the densities of excited states (up to n=15) as a function of electron temperature , electron density  and the molecular-to-atomic neutral ratio . The backward component of the model uses interpolation to obtain electron temperature as a function of Balmer ratio, electron density , and the molecular-to-atomic neutral ratio . This CR model could yield time resolved  predictions in the range 1-500 eV for hydrogen plasmas with up to cc and specified densities of molecular and atomic hydrogen neutrals. A comparison of different methods for determining the counts in a spectral line to calculate the Balmer line ratio and inferring the electron temperature is presented. The most trusted method in inferring the electron temperature is also discussed.