Kinetic Study of Electron Beam Excited Argon

Abstract

An experimental and theoretical study of the interaction between Argon and a high-energy short-pulse electron beam is reported. A theoretical model describing the argon atom and molecule with ten effective levels and taking into account all the reactions that these levels mny suffered is developped. A comparison, based on time resolved V.U.V. and visible fluorescences and electron density determination, between the theoretical and experimental results shows the ability of our model to describe the interaction in all the experimental range, 400 < P < 5000 Torr, studied.

Ar(1s5) absolute radial densities in a ns‐pulsed argon plasma jet impinging on dielectric targets at floating potential – plasma action on organic molecules

“…This modifies strongly the discharge dynamics. Another quenching mechanism refers to three body reactions between Ar(1s 5 ) and ground state argon atoms …”

“…This is reasonable as in these regions the argon jet is very pure and, thus, the above reaction should be the main destruction mechanism of Ar(1s 5 ). It should be noted that due to the rapid mixing of the four 4s‐levels of excited argon by collisions with electrons or atoms, they can be considered as only one effective state Ar* . At atmospheric pressure and 293 K, the lifetime of the Ar* equals to 242 ns .…”

“…Another quenching mechanism refers to three body reactions between Ar(1s 5 ) and ground state argon atoms. [40,41] The above remarks are based on the experimental results of the present study. The dominant reactions involved in the population/depopulation of Ar(1s 5 ) and their temporal evolution cannot be precisely discriminated.…”

“…It should be noted that due to the rapid mixing of the four 4s-levels of excited argon by collisions with electrons or atoms, they can be considered as only one effective state Ar*. [40,41] At atmospheric pressure and 293 K, the lifetime of the Ar* equals to 242 ns. [41] On the contrary, lower τ values were measured for Q = 0.3 l min −1 at z > 4 mm and −0.2 ≤ y ≤ 0.2 mm, and for Q = 0.4 l min −1 at extreme y coordinates.…”

Influence of Excited States on the Electron Distribution Function in an Argon Plasma for Discharge and Post-Discharge Conditions

“…We have replaced the e-beam heating term by a term corresponding to the applied electric field. The description of the kinetic model and the values of rate coefficients for the radiative decay, collisions of excited states with atoms and for Penning ionization processes were given in a previous paper [5].…”