Variations in Theories for Calculating the Coulomb Logarithm*

The motivation of this project is to implement a new model of ion-electron heat exchange in the FLASH code for the purpose of simulating various plasma physics processes in different plasma regimes. The ion-electron heat exchange rate is based on the calculation of the Coulomb logarithm. Two models currently exist in the FLASH code, the Landau-Spitzer and Lee-More models. Recent experiments have shown that these models are not accurate for strongly coupled plasmas and do not capture the full range of effects within plasmas. To this end, we have implemented three models within FLASH; the Gericke-Murillo-Schlanges (GMS), quantum Lenard-Balescu (qLB), Brown-Preston-Singleton (BPS), and static quantum Fokker-Plank (qFP) models. Each of these models represent a different theoretical framework for the calculation of the Coulomb Logarithm, but together they span a wide range of plasmas. These theories were implemented into the FLASH code, compared with the existing theories, and cross referenced with pre-existing results to verify accuracy.