Modeling of Wave Driven Molecular ( H 2 , N 2 , N 2 – Ar ) Discharges as Atomic Sources

Microwave H2, N2, and N2–Ar discharges driven by traveling surface waves are investigated as sources of ground state N(S), H(1s) atoms. The dissociation kinetics is discussed in the framework of theoretical models based on a self-consistent treatment of the main discharge balances, wave electrodynamics and plasma-wall interactions. It is shown that the number density of hydrogen H(1s) atoms depends heavily on the wall conditions at low pressure conditions. The kinetics of N( S) and metastable N( D) and N(P) atoms and of the molecular N2(A 3 )metastable state in a pure N2 discharge are shown to be strongly coupled. One possible way to control and to enhance nitrogen dissociation is the use of an N2–Ar mixture. The increase in dissociation degree of N2 molecules at high Ar fractional concentration can be attributed to dissociative recombination between electrons and N +2 positive ions. The predicted results for the atomic density are compared with emission spectroscopy data.

[1]  E. Tatarova,et al.  Wave driven N2–Ar discharge. I. Self-consistent theoretical model , 2002 .

[2]  E. Tatarova,et al.  On the self-consistent modeling of a traveling wave sustained nitrogen discharge , 2002 .

[3]  E. Tatarova,et al.  Kinetic theory of low-temperature plasmas in molecular gases , 2000 .

[4]  M. Pinheiro,et al.  A travelling wave sustained hydrogen discharge: modelling and experiment , 2000 .

[5]  C. M. Ferreira,et al.  Experimental investigation of surface wave propagation in collisional plasma columns , 1999 .

[6]  A. Ricard,et al.  On the axial structure of a nitrogen surface wave sustained discharge: Theory and experiment , 1999 .

[7]  E. Tatarova,et al.  Travelling Wave Discharges in Nitrogen: Modelling and Experiment , 1999 .

[8]  M. Chaker,et al.  Influence of the field frequency on the nitrogen atom yield in the remote plasma of an high frequency discharge , 1998 .

[9]  M. Pinheiro,et al.  Self-consistent kinetic model of low-pressure - flowing discharges: II. Surface processes and densities of N, H, species , 1998 .

[10]  M. Pinheiro,et al.  Self-consistent kinetic model of low-pressure - flowing discharges: I. Volume processes , 1998 .

[11]  C. M. Ferreira,et al.  SPATIALLY RESOLVED EXPERIMENTAL INVESTIGATION OF A SURFACE WAVE SUSTAINED DISCHARGE IN NITROGEN , 1998 .

[12]  M. Nagatsu,et al.  High-density flat plasma production based on surface waves , 1998 .

[13]  I. Zhelyazkov,et al.  Self-consistent kinetic model of a surface-wave-sustained discharge in nitrogen , 1997 .

[14]  V. Guerra,et al.  Electron and heavy particle kinetics in a low-pressure nitrogen glow discharge , 1997 .

[15]  V. A. Shakhatov,et al.  CARS study of the vibrational kinetics of nitrogen molecules in the burning and afterglow stages of a pulsed discharge , 1997 .

[16]  V. Guerra,et al.  Non-equilibrium coupled kinetics in stationary N2-O2 discharges , 1995 .

[17]  A. Viggiano,et al.  Rate constants for the reaction of Ar+(2P3/2) with N2 as a function of N2 vibrational temperature and energy level , 1993 .

[18]  Mohammadreza Safari.  Decharges microondes en ecoulement dans les melanges oxygene-azote comme sources d'oxygene atomique et singulet. Comparaison avec d'autres types de plasmas , 1992 .

[19]  Y. C. Kim,et al.  Recombination of oxygen, nitrogen, and hydrogen atoms on silica: kinetics and mechanism , 1991 .

[20]  A. Ricard,et al.  Active species in microwave postdischarge for steel-surface nitriding , 1990 .

[21]  T. Amano.  The dissociative recombination rate coefficients of H+3, HN+2, and HCO+ , 1990 .

[22]  Wetzel,et al.  Measurements of electron-impact-ionization cross sections of N2, CO, CO2, CS, S2, CS2, and metastable N2. , 1990, Physical review. A, Atomic, molecular, and optical physics.

[23]  C. M. Ferreira,et al.  Electron and vibrational kinetics in the hydrogen positive column , 1989 .

[24]  Bonnie,et al.  Observation of exceptionally high vibrational excitation of hydrogen molecules formed by wall recombination. , 1988, Physical review letters.

[25]  V. Ostrovsky,et al.  Non-Franck-Condon transitions in the electron impact excitation of molecules. II. Semi-empirical approach: transitions in H2 , 1981 .

[26]  J. Bacri,et al.  Electron diatomic molecule weighted total cross section calculation: I. Principles for calculation , 1980 .

[27]  A. Phelps,et al.  Quenching of N2(A 3Σ+u, v=0,1) by N2, Ar, and H2 , 1978 .

[28]  C. Lin,et al.  Application of the close-coupling method to excitation of electronic states and dissociation of H 2 by electron impact , 1978 .

[29]  W. D. Robb,et al.  The scattering of electrons by atomic nitrogen , 1975 .

[30]  T. Slanger,et al.  Measurements of vibrationally excited molecules by Raman scattering. I The yield of vibrationally excited nitrogen in the reaction N+NO → N2+O , 1973 .

[31]  A. J. Cunningham,et al.  Dissociative recombination at elevated temperatures. II. Comparison between theory and experiment in neon and argon afterglows , 1972 .

[32]  D. Rapp,et al.  Total Cross Sections for Ionization and Attachment in Gases by Electron Impact. I. Positive Ionization , 1965 .