TY - JOUR

T1 - Hydrodynamic model of a dielectric-barrier discharge in pure chlorine

AU - Avtaeva, S. V.

PY - 2017/8/1

Y1 - 2017/8/1

N2 - A one-dimensional hydrodynamic model of a dielectric-barrier discharge (DBD) in pure chlorine is developed, and the properties of the discharge are modeled. The discharge is excited in an 8-mm-long discharge gap between 2-mm-thick dielectric quartz layers covering metal electrodes. The DBD spatiotemporal characteristics at gas pressures of 15–100 Torr are modeled for the case in which a 100-kHz harmonic voltage with an amplitude of 8 kV is applied to the electrodes. The average power density deposited in the discharge over one voltage period is 2.5–5.8 W/cm3. It is shown that ions and electrons absorb about 95 and 5% of the discharge power, respectively. In this case, from 67 to 97% of the power absorbed by electrons is spent on the dissociation and ionization of Cl2 molecules. Two phases can be distinguished in the discharge dynamics: the active (multispike) phase, which follows the breakdown of the discharge gap, and the passive phase. The active phase is characterized by the presence of multiple current spikes, a relatively high current, small surface charge density on the dielectrics, and large voltage drop across the discharge gap. The passive phase (with no current spikes) is characterized by a low current, large surface charge density on the dielectrics, and small voltage drop across the discharge gap. The peak current density in the spikes at all pressures is about 4 mA/cm2. In the multispike phase, there are distinct space charge sheaths with thicknesses of 1.5–1.8 mm and a mean electron energy of 4.3–7 eV and the central region of quasineutral plasma with a weak electric field and a mean electron energy of 0.8–3 eV. The degree of ionization of chlorine molecules in the discharge is ~0.02% at a pressure of 15 Torr and ~0.01% at 100 Torr. The DBD plasma is electronegative due to the fast attachment of electrons to chlorine atoms: e + Cl2 → Cl + Cl–. The most abundant charged particles are Cl2 + and Cl− ions, and the degree of ionization during current spikes in the active phase is (4.1–5.5) × 10–7. The mechanism of discharge sustainment is analyzed. The appearance of a series of current spikes in the active phase of the discharge is explained.

AB - A one-dimensional hydrodynamic model of a dielectric-barrier discharge (DBD) in pure chlorine is developed, and the properties of the discharge are modeled. The discharge is excited in an 8-mm-long discharge gap between 2-mm-thick dielectric quartz layers covering metal electrodes. The DBD spatiotemporal characteristics at gas pressures of 15–100 Torr are modeled for the case in which a 100-kHz harmonic voltage with an amplitude of 8 kV is applied to the electrodes. The average power density deposited in the discharge over one voltage period is 2.5–5.8 W/cm3. It is shown that ions and electrons absorb about 95 and 5% of the discharge power, respectively. In this case, from 67 to 97% of the power absorbed by electrons is spent on the dissociation and ionization of Cl2 molecules. Two phases can be distinguished in the discharge dynamics: the active (multispike) phase, which follows the breakdown of the discharge gap, and the passive phase. The active phase is characterized by the presence of multiple current spikes, a relatively high current, small surface charge density on the dielectrics, and large voltage drop across the discharge gap. The passive phase (with no current spikes) is characterized by a low current, large surface charge density on the dielectrics, and small voltage drop across the discharge gap. The peak current density in the spikes at all pressures is about 4 mA/cm2. In the multispike phase, there are distinct space charge sheaths with thicknesses of 1.5–1.8 mm and a mean electron energy of 4.3–7 eV and the central region of quasineutral plasma with a weak electric field and a mean electron energy of 0.8–3 eV. The degree of ionization of chlorine molecules in the discharge is ~0.02% at a pressure of 15 Torr and ~0.01% at 100 Torr. The DBD plasma is electronegative due to the fast attachment of electrons to chlorine atoms: e + Cl2 → Cl + Cl–. The most abundant charged particles are Cl2 + and Cl− ions, and the degree of ionization during current spikes in the active phase is (4.1–5.5) × 10–7. The mechanism of discharge sustainment is analyzed. The appearance of a series of current spikes in the active phase of the discharge is explained.

KW - ELECTRONEGATIVE RADIOFREQUENCY DISCHARGES

KW - CAPACITIVELY COUPLED DISCHARGES

KW - RF GLOW-DISCHARGES

KW - CONTAINING PLASMAS

KW - OPTICAL-EMISSION

KW - GAS TEMPERATURE

KW - DIAGNOSTICS

KW - CL-2

KW - DENSITIES

KW - ION

UR - http://www.scopus.com/inward/record.url?scp=85032328604&partnerID=8YFLogxK

U2 - 10.1134/S1063780X17080037

DO - 10.1134/S1063780X17080037

M3 - Article

AN - SCOPUS:85032328604

VL - 43

SP - 876

EP - 890

JO - Plasma Physics Reports

JF - Plasma Physics Reports

SN - 1063-780X

IS - 8

ER -