Study of two-body and three-body channels for the reaction of metastable helium atoms with nitrogen

This work reports the characterization of late time periods in the decay of metastable He(2 3S) atoms produced in 1–4 atm of helium containing up to 1400 mTorr of N2. Results have been obtained that exploit the large dynamic range and high data acquisition rates available from time resolved spectroscopic studies of preionized stripline discharges. A new value was found for the termolecular reaction of (2 3S) with N2 of 1.5×10−31 cm6 s−1 that is in good agreement with a model of collisionally induced capture. An indirect channel of reaction was also found that seems to explain the anomalously rapid and conflicting termolecular rates that were previously reported.