Numerical study of secondary electron emission in a coaxial   radio-frequency driven plasma jet at atmospheric pressure
  In this work we investigate a numerical model of a coaxial RF-driven plasma jet operated at atmospheric pressure. Due to the cylindrical symmetry an adequate 2-D representation of the otherwise 3-dimensional structure is used. A helium-oxygen chemistry reaction scheme is applied. We study the effect of secondary electrons emitted at the inner electrode as well as the inserted dielectric tube and discuss their impact on the discharge behavior. We conclude that a proper choice of materials can improve the desired mode of operation of such plasma jets in terms of materials and surface processing. 
Torben Hemke, Jan Trieschmann, Alexander Wollny, Ralf Peter Brinkmann,   Thomas Mussenbrock
physics.plasm-ph