Abstract
We report time and wavelength resolved studies of the vacuum-ultraviolet (VUV) emission from a windowless dielectric barrier discharge (DBD) in helium. Short-pulse voltage excitation is utilised to clearly resolve the fast and slow temporal components of the Hopfield continuum between λ = 60-120 nm. Experimental results and theoretical modelling of the spectral distributions indicate that the two components of the VUV emission must originate from the same radiating molecular state - , and that two distinct pumping mechanisms populate this state. The time evolution of the fast component is found to correlate with that from the (0,0) molecular transition (λ = 513.4 nm). Thus the state is initially rapidly pumped via radiative cascade from higher molecular states. In addition, the observed band emissions from the molecular v=0 and v=0 states and the line emissions from the atomic He∗(n = 3) states all exhibit similar temporal behaviour during the discharge excitation period. Our results are consistent with the recent report of Frost et al (J. Phys. B 34 1569 2001) concerning the existence of a so-called 'neglected channel' to fast production from He∗(n = 3) atomic state precursors.
| Language | English |
|---|---|
| Article number | 085201 |
| Pages | 1-18 |
| Number of pages | 18 |
| Journal | Journal of Physics D: Applied Physics |
| Volume | 49 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2 Mar 2016 |
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Time-resolved vacuum-ultraviolet emission (λ = 60-120 nm) from a high pressure DBD-excited helium plasma : formation mechanisms of the fast component. / Carman, R. J.; Ganesan, R.; Kane, D. M.
In: Journal of Physics D: Applied Physics, Vol. 49, No. 8, 085201, 02.03.2016, p. 1-18.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Time-resolved vacuum-ultraviolet emission (λ = 60-120 nm) from a high pressure DBD-excited helium plasma
T2 - Journal of Physics D: Applied Physics
AU - Carman, R. J.
AU - Ganesan, R.
AU - Kane, D. M.
PY - 2016/3/2
Y1 - 2016/3/2
N2 - We report time and wavelength resolved studies of the vacuum-ultraviolet (VUV) emission from a windowless dielectric barrier discharge (DBD) in helium. Short-pulse voltage excitation is utilised to clearly resolve the fast and slow temporal components of the Hopfield continuum between λ = 60-120 nm. Experimental results and theoretical modelling of the spectral distributions indicate that the two components of the VUV emission must originate from the same radiating molecular state - , and that two distinct pumping mechanisms populate this state. The time evolution of the fast component is found to correlate with that from the (0,0) molecular transition (λ = 513.4 nm). Thus the state is initially rapidly pumped via radiative cascade from higher molecular states. In addition, the observed band emissions from the molecular v=0 and v=0 states and the line emissions from the atomic He∗(n = 3) states all exhibit similar temporal behaviour during the discharge excitation period. Our results are consistent with the recent report of Frost et al (J. Phys. B 34 1569 2001) concerning the existence of a so-called 'neglected channel' to fast production from He∗(n = 3) atomic state precursors.
AB - We report time and wavelength resolved studies of the vacuum-ultraviolet (VUV) emission from a windowless dielectric barrier discharge (DBD) in helium. Short-pulse voltage excitation is utilised to clearly resolve the fast and slow temporal components of the Hopfield continuum between λ = 60-120 nm. Experimental results and theoretical modelling of the spectral distributions indicate that the two components of the VUV emission must originate from the same radiating molecular state - , and that two distinct pumping mechanisms populate this state. The time evolution of the fast component is found to correlate with that from the (0,0) molecular transition (λ = 513.4 nm). Thus the state is initially rapidly pumped via radiative cascade from higher molecular states. In addition, the observed band emissions from the molecular v=0 and v=0 states and the line emissions from the atomic He∗(n = 3) states all exhibit similar temporal behaviour during the discharge excitation period. Our results are consistent with the recent report of Frost et al (J. Phys. B 34 1569 2001) concerning the existence of a so-called 'neglected channel' to fast production from He∗(n = 3) atomic state precursors.
UR - http://www.scopus.com/inward/record.url?scp=84957586285&partnerID=8YFLogxK
U2 - 10.1088/0022-3727/49/8/085201
DO - 10.1088/0022-3727/49/8/085201
M3 - Article
VL - 49
SP - 1
EP - 18
JO - Journal of Physics D: Applied Physics
JF - Journal of Physics D: Applied Physics
SN - 0022-3727
IS - 8
M1 - 085201
ER -