A global (volume averaged) model of a chlorine discharge

Abstract

A steady state global (volume averaged) model is developed for the chlorine discharge using a revised reaction set. Various calculated plasma parameters are compared with measurements found in the literature, showing a good overall agreement. The reaction rates for the various reactions are evaluated in the pressure range 1-100 mTorr. In particular, we explore the dissociation process as well as the creation and destruction of the negative ions Cl − . The discharge is highly dissociated throughout the pressure range explored, 1-100 mTorr, even when the absorbed power is low. The mechanism for Cl creation is complex. Although electron impact dissociation dominates with roughly 60-65% contribution, mutual neutralization of positive and negative ions and dissociative electron attachment are important contributors to the production of Cl atoms at high pressure. The electronegativity increases rapidly with decreasing dissociation fraction since the Cl − ions are created entirely by dissociative electron attachment, predominantly from Cl 2 (v = 0), but also up to 14% from Cl 2 (v > 0) at 100 mTorr. The negative ion Cl − is lost almost entirely through mutual neutralization with Cl + 2 at high pressure while Cl + has a significant contribution at low pressure.

Global (volume-averaged) model of inductively coupled chlorine plasma: Influence of Cl wall recombination and external heating on continuous and pulse-modulated plasmas

“…Additionally, such a dependence is also observed for a stainless steel wall by Stafford et al [8]. We define these variable recombination probabilities by parametric fits [19] log 10 (γ A2 ) = −0.82 − 1.59 exp −1.81 n Cl n Cl 2 ,…”

“…The former is represented by {P } and the latter by {D}. Based on these notations, the source is written as [19] …”

“…We employ a fit function for γ > 10, presented in [19], with the assumption that α b is equal to the central degree of electronegativity.…”

“…Compared with similar chlorine studies [10,19], we explicitly include the atomic excited levels Cl( 2 P 1/2) and Cl( 1 P 5/2). The reactions and the rate coefficients are listed in table 4.…”

A Global Enhanced Vibrational Kinetic Model for High-Pressure Hydrogen RF Discharges

“…Therefore, at low electronegativity, instead of solving (27), α s = 0 or the analytic expression for α s in terms of α 0 and γ derived in [49] can be used. At higher pressures, however, the temperature ratio could be relatively low γ 1, thus making α s ≈ α b .…”