Nitrogen Oxide Production in Laser‐Induced Breakdown Simulating Impacts on the Hadean Atmosphere
A. N. Heays, Tereza Kaiserová, Paul B. Rimmer, Antonín Knížek, Lukáš Petera, Svatopluk Civiš, L. Juha, R. Dudžák, M. Krůs, Manuel Scherf, H. Lämmer, Robert Pascal, Martin Ferus
Abstract
Abstract The high‐energy‐density synthesis of N x O y species is simulated in gas mixtures representing an O 2 ‐free early‐Earth atmosphere by terawatt‐kilojoule‐class laser‐induced dielectric breakdown (LIDB). These experiments differ from previous LIDB experiments due to the 100 times greater energy delivered per pulse and sensitive analysis of products by high‐resolution infrared spectroscopy. The measured yields of NO, N 2 O, and NO 2 are 0.08–8 × 10 15 , 5 × 10 12 , and 0.03–7 × 10 14 molec J −1 . The high N 2 O yield is above the upper‐limit constraint of previous tabletop LIDB experiments and the expected yield of a thermochemical freeze‐out at any temperature between 2000 and 5000 K, while the NO and NO 2 yields are in broad agreement with freeze‐out models. Using a one dimensional chemical model of the Hadean atmosphere and a simple model of late bombardment, we compute the source flux of N 2 O assuming the same high production yield as measured experimentally and find the steady‐state partial pressure of N 2 O is insufficient to warm the climate.