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D. Babánková

M. Bittner

J. Cihelka

S. Civiš

J. Cvačka

O. Frank

J. Jehlička

L. Juha

J. Krása

P. Kubát

A. Muck

J. Skála

Large Laser Sparks

Large Laser Sparks for laboratory simulation of high-energy-density events in planetary atmospheres

Single ≤ 1 kJ pulses from a high-power laser are focused into molecular gases to create large laser sparks. This provides a unique way to mimic the chemical effects of high-energy-density events in planetary atmospheres (cometary impact, lightning), matching the natural energy-density and plasma-volume scaling of such events in a fully-controlled laboratory environment. The many chemical reactions initiated by laser-induced dielectric breakdown (LIBD) in both neat molecular gases and in mixtures with compositions related to the study of the chemical evolution of the Earth’s early atmosphere are systematically studied. The processes responsible for the chemical action of laser sparks are identified and investigated. The results of our high-energy single-pulse experiments will be compared with the results for many low-energy pulses from high-repetition-rate lasers, where reaction products from earlier pulses may undergo additional reactions due to LIDB by later pulses.

Recent publications

S. Civiš, L. Juha, D. Babánková, J. Cvačka, O. Frank, J. Jehlička, B. Králiková, J. Krása, P. Kubát, A. Muck, M. Pfeifer, J. Skála, J. Ullschmied: Amino acid formation induced by a high-power laser in CO2/CO-N2-H2O gas mixtures, Chem. Phys. Lett. 386, 169–173 (2004)

    In mixtures of molecular gases with compositions of CO2-N2-H2O or CO-N2-H2O and total pressure close to that of the Earth’s early atmosphere, a centimeter-sized plasma was created by focusing a single 85-J, 450-ps near-infrared laser pulse in the center of a 15-L gas cell. Chemical consequences of laser-produced plasma generation in such a mixture were investigated by means of liquid chromatography equipped with a mass-spectrometric detector (HPLC-MS). Amino acids were identified in both reaction mixtures after they had been exposed to ten laser shots.

D. Babánková, S. Civiš, L. Juha: Chemical consequences of laser-induced dielectric breakdown in molecular gases, Chem. Listy, 99, 109–115 (2005).

    Chemical reactions initiated by laser-induced dielectric breakdown (LIDB) in homogeneous molecular gases are reviewed. Attention is paid to processes induced in gas mixtures, prepared according to the expected composition of planetary atmospheres, in order to simulate the chemical effects of high-energy-density events (e.g. cometary impact and lightning) in these atmospheres. Utilization of a single pulse from a high-power laser system for this purpose is discussed. The particular processes responsible for the chemical action of laser sparks are identified and described in detail.

Collaborating groups