ArF laser photodissociation of NH3 at 193 nm: internal energy distributions in NH2 X̃2B1 and Ã2A1, and two-photon generatin of NH A 3Π and b 1Σ+

摘要: Abstract Ammonia is photolyzed with an ArF excimer laser at 193 nm. NH 2 formed in the A 1 state, detected through identification of → X B emission bands between 620 and 1100 nm, also identified by dye induced fluorescence on ← transition. The A-state yield about 2.5% relative to X-state. state has a propensity for being high K rotational levels v vibrational appear be populated monotonically decreasing distribution, average energy content 1000 cm −1 . Rotational populations are deduced 050 Σ level state. colder-than-room-temperature distribution ( T TDI = 210 ± 40 K) explained angular momentum conservation arguments. features observed excitation spectrum A←X could not assigned near collision-free pressures. However, under thermalized conditions, 090 000 Σ, Δ, 0 100 - π φ clearly identified. Arguments presented which show that nascent photofragment created either population, or population inverted. 3 Π − b + 336 471 respectively. Formation si attributed two-photon resonance processes