Akademik Veri Yönetim Sistemi
Rafatov I. (Yürütücü)
TÜBİTAK Uluslararası İkili İşbirliği Projesi, 2022 - 2024
The project deals with the investigation of atmospheric
pressure DC glow discharge (APGD) in helium.
One- and two-dimensional numerical models for simulations of
the APGD in helium are developed and verified. The models are based on a fluid
description of charged and neutral particles and a drift-diffusion
approximation for particle fluxes. The performance of the models is analyzed by
studying the effects of several factors (such as the form of the electron
energy distribution function (Maxwellian vs non-Maxwellian), the description of
plasma-chemical processes, the secondary electron emission coefficient, energy
loss due to gas heating, thermal diffusion, and the width of the discharge gap)
on the discharge characteristics.
Studies revealed a significant effect of the temperature
regime on the cathode (cooled vs uncooled cathode) on the basic discharge parameters
(such as the electric field profile, thickness of the cathode fall layer,
current density, and gas temperature) of the cathode fall of the APGD in
helium. An analysis of the formation of normal APGD is carried out, which
revealed good agreement with experimental data. The transition of the discharge
to an obstructed mode with gas heating is investigated. The spontaneous
emergence and self-organization of current structures (such as cathode spots
and ring patterns) is studied. The parameter dependence of nonlinear
oscillations of the APGD in the subnormal mode is investigated. The dynamical behavior
of the system is analyzed and bifurcation diagrams are constructed.
The results provide new insight into the fundamental
physical processes occurring in the plasma of high (atmospheric) pressure glow
discharges. In particular, the data obtained contribute to understanding of the
dynamical behavior of APGDs, and provides useful information from the point of
view of increasing stability and efficiency of their operation.