Experimental insights on experimental volcanic lightning under varying atmospheric conditions

This data publication provides data from 39 experiments performed in 2021 to 2022 in the Gas-mixing lab at the Ludwig Maximilian University of Munich (Germany). The experiments were conducted to investigate the charging and discharging potential of decompressed soda-lime glass beads in varying enveloping gas composition and two different transporting gas species (argon and nitrogen). The experimental setup is a modified version of an apparatus first developed by Alidibirov and Dingwell (1996) and further modified by Cimarelli et al. (2014), Gaudin and Cimarelli (2019), and Stern et al. (2019) to enable the detection and quantification of discharges caused by the interaction of the discharging particles. The latest modifications enable the setup to perform experiments under gas-tight conditions allowing to test different atmospheric composition and pressure and to sample the gas within the particle collector tank. The sample material was ejected from the autoclave into the particle collector tank that is insulated from the autoclave and works as a Faraday cage. Discharges going from the jet to the nozzle were recorded by a datalogger. Additionally, the ejection of the decompressed material was recorded by a high-speed camera. The gas composition in the collector tank was changed from air to CO2 and a mixture of CO2 and CO. The particle collector tank was conditioned in two different modes: purging three times the tank with the desired gas composition or three times of purging and applying a vacuum in between. Analysis of gas samples taken from the collector tank before conducting the experiments revealed that in both cases a complete removal of the air was not achieved, but significantly reduced by the evacuation-purging method. Two gases were used to pressurize the sample within the autoclave: Nitrogen and Argon. The experimental results were compared to previous experiments (Springsklee et al., 2022a; Springsklee et al., 2022b).