Measurement of temperatures in optically thick railgun plasma armatures

In this paper, the authors present Bartels´ method for estimating temperatures from the spectra of optically thick plasma armatures. They have applied this method to the analysis of spectra from the Thunderbolt and UTSI railguns and the results of the analysis are presented. Temperatures estimated from Bartels´ method are on average 45% lower compared to temperatures estimated by the solution of the radiation transfer equation. The authors have also estimated temperatures via black body approximation conductivity measurements, and the application of Stefan-Boltzmann law. They have found the temperatures estimated from these methods to be lower than the values estimated by the solution of the radiation transfer equation. This has led them to believe that the temperatures in the plasma armatures are lower than previously estimated by the solution of the radiation transfer equations.<>