TY - JOUR

T1 - Spatial and temporal formation dynamics of glow discharge constriction and stratification

AU - Golubovskii, Yu B.

AU - Siasko, A. V.

AU - Kalanov, D. V.

AU - Nekuchaev, V. O.

PY - 2018/8/30

Y1 - 2018/8/30

N2 - In the present work, we experimentally study the formation dynamics of positive column constriction in neon glow discharge at intermediate pressures (pR = 50 ± 500 Torr cm) with the simultaneous development of longitudinal instabilities in the form of moving striations. Discharge current, which exceeded the critical value for the transition to the constricted regime, was modulated by short rectangular pulses in order to avoid the inhomogeneous heating of the gas. During the pulse, the ionization balance was establishing and then discharge was switching to the constricted regime. The temperature field of neutral atoms was determined using interferometric methods based on a scheme of the Michelson interferometer. The heat equation was solved for the stationary and pulsed regimes. It is shown that under the described discharge conditions, in spite of the absence of inhomogeneous gas heating, discharge switches to the constricted regime with the appearance of moving striations. On the basis of the performed experiments, it can be concluded that inhomogeneous gas heating in neon is not the main cause of discharge constriction. A nonlinear dependence of the ionization rate on the electron density related to the Maxwellization of the electron energy distribution function should be considered as the basic mechanism of constriction.

AB - In the present work, we experimentally study the formation dynamics of positive column constriction in neon glow discharge at intermediate pressures (pR = 50 ± 500 Torr cm) with the simultaneous development of longitudinal instabilities in the form of moving striations. Discharge current, which exceeded the critical value for the transition to the constricted regime, was modulated by short rectangular pulses in order to avoid the inhomogeneous heating of the gas. During the pulse, the ionization balance was establishing and then discharge was switching to the constricted regime. The temperature field of neutral atoms was determined using interferometric methods based on a scheme of the Michelson interferometer. The heat equation was solved for the stationary and pulsed regimes. It is shown that under the described discharge conditions, in spite of the absence of inhomogeneous gas heating, discharge switches to the constricted regime with the appearance of moving striations. On the basis of the performed experiments, it can be concluded that inhomogeneous gas heating in neon is not the main cause of discharge constriction. A nonlinear dependence of the ionization rate on the electron density related to the Maxwellization of the electron energy distribution function should be considered as the basic mechanism of constriction.

KW - constriction

KW - gas heating

KW - glow discharge

KW - interferometry

KW - plasma instabilities

KW - positive column

KW - striations

KW - INSTABILITY

KW - POSITIVE-COLUMN

KW - NEON

KW - DIFFUSE

KW - NITROGEN

KW - RARE-GASES

KW - PLASMA-COLUMN

UR - http://www.scopus.com/inward/record.url?scp=85053147770&partnerID=8YFLogxK

U2 - 10.1088/1361-6595/aad799

DO - 10.1088/1361-6595/aad799

M3 - Article

AN - SCOPUS:85053147770

VL - 27

JO - Plasma Sources Science and Technology

JF - Plasma Sources Science and Technology

SN - 0963-0252

IS - 8

M1 - 085009

ER -