Fast gas heating in nitrogenoxygen discharge plasma: II. Energy exchange in the afterglow of a volume nanosecond discharge at moderate pressures

The process of fast gas heating in air in the near afterglow of a pulsed nanosecond spatially uniform discharge has been investigated experimentally and numerically at moderate (3−9 mbar) pressures and high (200−400 Td) reduced electric fields. The temporal behavior of discharge current, deposited energy, electric field and temperature were measured. The role of processes with participation of excited and charged species was analyzed. It was shown that under the considered conditions the main energy release takes place in reactions of nitrogen and oxygen dissociation by electron impact and quenching of electronically excited nitrogen molecules, such as N2(AΣu , B Πg, CΠu, a’Σu ) by oxygen and quenching of excited O( D) atoms by N2. It was shown that about 24% of the discharge energy goes to fast gas heating during first tens of microseconds after the discharge. Fast gas heating. II. Energy exchange in nanosecond discharge 2