TY - JOUR
T1 - Simultaneous measurement of nitrogen and hydrogen dissociation from vacuum ultraviolet self-absorption spectroscopy in a developing low temperature plasma at atmospheric pressure
AU - Laity, George
AU - Fierro, Andrew
AU - Dickens, James
AU - Neuber, Andreas
AU - Frank, Klaus
N1 - Funding Information:
This work was supported by the U.S. Air Force Office of Scientific Research (AFOSR) grant on the “Basic Physics of Distributed Plasma Discharge.” G. Laity was under fellowship support from the Directed Energy Professional Society and the Directed Energy Scholar program at the U.S. Air Force Research Laboratory (AFRL). A. Fierro was under fellowship support from the National Physical Science Consortium in partnership with Sandia National Laboratories. The authors would like to thank the National Institute of Standards and Technology (NIST) for the Atomic Spectra Database (ASD) available online.
PY - 2013/5/6
Y1 - 2013/5/6
N2 - We demonstrate a method for determining the dissociation density of N and H atoms present in a developing low temperature plasma, based on the emission and self-absorption of vacuum ultraviolet radiation produced from the plasma. Spark plasmas are produced via pulsed discharge in N2/H2 mixtures at atmospheric pressure, where information on the dissociated densities of the constituent gas molecules is desired without employing invasive diagnostic techniques. By analyzing the self-absorption line profile of 121.5 nm Lyman-α H radiation emitted within the first ∼1.0 mm of plasma near the anode tip, a peak dissociated H atom concentration of 5.6 × 10 17 cm-3 was observed ∼100 ns into spark formation, with an estimated electron density of 2.65 × 1018 cm -3 determined from Stark broadening. Similarly, simultaneous line fitting of the N 120.0/124.3 nm emission profiles revealed a peak dissociated N atom concentration of 3.8 × 1017 cm-3 during the same discharge period.
AB - We demonstrate a method for determining the dissociation density of N and H atoms present in a developing low temperature plasma, based on the emission and self-absorption of vacuum ultraviolet radiation produced from the plasma. Spark plasmas are produced via pulsed discharge in N2/H2 mixtures at atmospheric pressure, where information on the dissociated densities of the constituent gas molecules is desired without employing invasive diagnostic techniques. By analyzing the self-absorption line profile of 121.5 nm Lyman-α H radiation emitted within the first ∼1.0 mm of plasma near the anode tip, a peak dissociated H atom concentration of 5.6 × 10 17 cm-3 was observed ∼100 ns into spark formation, with an estimated electron density of 2.65 × 1018 cm -3 determined from Stark broadening. Similarly, simultaneous line fitting of the N 120.0/124.3 nm emission profiles revealed a peak dissociated N atom concentration of 3.8 × 1017 cm-3 during the same discharge period.
UR - http://www.scopus.com/inward/record.url?scp=84877732883&partnerID=8YFLogxK
U2 - 10.1063/1.4804369
DO - 10.1063/1.4804369
M3 - Article
AN - SCOPUS:84877732883
SN - 0003-6951
VL - 102
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 18
M1 - 184104
ER -