Surveying the acoustics from laser-induced plasmas under non-standard atmospheric conditions: Implications for extraterrestrial missions

Abstract

The snapping sound accompanying laser produced plasmas are standing out in recent times as a complementary source of information to the spectroscopic measurements, allowing to catalogue occurring processes as well as to categorize inspected samples. These promising uses are currently considered for the identification of geological material and the characterization of the Martian atmosphere by the SuperCam instrument and its microphone onboard the NASA Perseverance rover. The singularity of each laser plasma, combined with the effect of the different atmospheric environments in which its expansion can occur (composition, pressure, temperature, etc.) provides multiple scenarios that affect the analytical signals generated. Despite the extensive bibliography on the effects of the surrounding atmosphere on the optical emission of laser-induced plasmas, little has been studied about the acoustics derived out of them. The present work aims to systematically scrutinize the effect of the more common atmospheric variables like pressure, temperature and composition into the final acoustic signal from laser-induced plasmas to accurately use this information source.