(47) The Sun in Our Lab: Formation and Analysis of Discharge Tube Plasma

Plasma is the most abundant state of matter in the universe, yet its physics is still being discovered. Through an interest driven by the prospect of fusion energy, the vast majority of plasma physics experiments now occur at... [ view full abstract ]

Plasma is the most abundant state of matter in the universe, yet its physics is still being discovered. Through an interest driven by the prospect of fusion energy, the vast majority of plasma physics experiments now occur at the scale of multi-million, even multi-billion, dollar experimental setups; nevertheless, an introductory experimental understanding of the physics of plasma can be undertaken here at Sewanee with the tabletop experiment of a vacuum discharge tube. Using this setup, we present the physics of monoatomic (argon) and diatomic (nitrogen) gas-discharge plasma. Specifically, we determined for both gases their Paschen's law coefficients for breakdown voltage and Goldstein-Wehner coefficients of prime striation thickness. We further discuss computational modeling of the experimental system as a diagnostic technique for plasma characteristics and use a Langmuir probe diagnostic to experimentally determine these characteristics and cross-validate the computational model.