Absolute Atomic Oxygen Density Measurements by Two-Photon Laser-induced Fluorescence (TALIF) in the Effluent of an Atmospheric Pressure Plasma Jet
Abstract
A 13.56 MHz RF-excited plasma jet^1 is diagnosed in this work. The jet operates at ambient conditions. It generates a homogeneous plasma in helium or argon^2 with admixtures ( ∼ 1 %) of molecular gases, here oxygen. The temperature of the effluent is well below 100 C. The jet has been set up in a planar and a concentric version; both were compared by means of TALIF-measurements. Absolute atomic oxygen density profiles have been measured in the effluent of the plasma jet. The atomic oxygen density close to the nozzle amounts to 10^16 cm-3. Even at several centimeters from the nozzle there still is 1% of the initial oxygen density. Emission spectroscopy down to 110 nm has been carried out as a function of distance from the exit nozzle with the effluent hitting an MgF2 window in front of the slit of a vacuum UV monochromator. These spectra exhibit strong emission lines e.g. of oxygen at 130 nm, even at a distance of several centimeters from the nozzle. This work was supported by the ``Ministerium f"ur Wissenschaft und Forschung NRW''
^1J. Y. Jeong, S. E. Babayan, V. J. Tu, J. Park, R. F. Hicks, and G. S. Selwyn, PSST 7, 282 (1998).
^2S. Wang, V. Schulz-von der Gathen, H.F. D"obele, Appl. Phys. Lett. 83, 3272 (2003)
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 2006
- Bibcode:
- 2006APS..GECQR1003R