Microdischarge Sources of O2(singlet Delta)
Abstract
The focus was to obtain yield measurements in DC microdischarges but there will also be an important modeling component conducted in parallel with the experiments. The existing MHCD model was developed for rare gases, and this will be extended to include a description of the O2 kinetics based on previously published work. A particularly important parameter is the gas temperature and the gas heating source term in the model also needs to be extended to include V-T (vibrational to translation) energy exchange ion heating in the sheath (expected to be the dominant component) is included in our present model). We originally proposed measuring the O2(1D) yield using IR absorption spectroscopy and we still feel that it will eventually be necessary to develop this or another or the more traditional spectroscopic methods (eg CARS or UV absorption). However, during the proof-of-principle phase of this project we propose using an isothermal calorimeter as has been developed previously for measurements of O2(1D) yields by several groups 7.8. We have been in contact with Dr, Ikonnikov and he has kindly provided us with additional information on the set-up of Lodin et a17. This calorimetric technique is, in our opinion the best way to obtain a quick inexpensive and accurate estimate of the O2(1D) yield in a single microdiecharge operating in a DC mode, The experimental set-up is simple a nickel coil is positioned in the gas flow on the downstream side of the microdischarge and the chemical energy in the gas flow is detected as a change in the external power required to maintain the coil at a constant temperature (eg 150 degrees C). This power is reduced when O2(1D) is deactivated at the coil surface. The Russian group7 used a self-balancing bridge circuit to maintain the constant temperature and they calibrated their system by measuring the O2(1D) emission signal before and after the detector. They determined that between 70 and 90% of the O2(1D) reacted with the nickel coil.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 2006
- Accession Number
- ADA462987
Entities
People
- Antoine Rousseau
- Jean-Pierre Boeuf
- Leanne C. Pitchford
- Vincent Puech