Breakdown of deuterium with a ruby laser

Solving the quantum-kinetic equation for electrons interacting with deuterium molecules and a 1.8-eV photon field, we have made time-dependent calculations of the breakdown of deuterium gas by a ruby laser. We find that the quantum flux G corresponding to the breakdown threshold E field is given by an equation which is approximately of the form ln 44 = ln[δt/A(G/ω)] - B(ω/G)1/2where Δt and ω are the laser pulse length and frequency, and A and B are constants. The field strength thresholds which emerge from these calculations are compared with available experimental data, and good agreement is obtained.