Evolution of metastable state molecules N2(A3Σu+) in a nanosecond pulsed discharge: A particle-in-cell/Monte Carlo collisions simulation

A particle-in-cell plus Monte Carlo collisions method has been employed to investigate the nitrogen discharge driven by a nanosecond pulse power source. To assess whether the production of the metastable state N-2(A(3)Sigma(+)(u)) can be efficiently enhanced in a nanosecond pulsed discharge, the evolutions of metastable state N-2(A(3)Sigma(+)(u)) density and electron energy distribution function have been examined in detail. The simulation results indicate that the ultra short pulse can modulate the electron energy effectively: during the early pulse-on time, high energy electrons give rise to quick electron avalanche and rapid growth of the metastable state N-2(A(3)Sigma(+)(u)) density. It is estimated that for a single pulse with amplitude of -9 kV and pulse width 30 ns, the metastable state N-2(A(3)Sigma(+)(u)) density can achieve a value in the order of 10(9) cm(-3). The N-2(A(3)Sigma(+)(u)) density at such a value could be easily detected by laser-based experimental methods. (C) 2012 American Institute of Physics. [doi:10.1063/1.3677261]