Modeling of the Distinctive Ground-State Atomic Oxygen Density Profile in Plasma Needle Discharge at Atmospheric Pressure

Autor:	Xiao-Chang Chen, Cong-Ying Yang, Dezhen Wang, Song Liu, Gengsong Ni, Mu-Yang Qian
Rok vydání:	2015
Předmět:	Materials science Atmospheric pressure General Physics and Astronomy chemistry.chemical_element Plasma Volumetric flow rate chemistry Penning ionization Ionization Physics::Atomic Physics Atomic physics Ground state Electron ionization Helium
Zdroj:	Chinese Physics Letters. 32:075202
ISSN:	1741-3540 0256-307X
Popis:	A two-dimensional coupled model of neutral gas flow and plasma dynamics is presented to explain the two distinctive patterns of ground-state atomic oxygen density profiles that have been observed experimentally in the helium plasma needle discharge. When the gas flow rate is 0.25 standard liter per minute (SLM), the discharge is substantially sustained by the electron impact ionization of air near a dielectric surface, corresponding to the radial density peaks along the axis of the symmetry. However, as the flow rate is 1.1 SLM, Penning ionization between helium metastables and surrounding air dominates the ionization reactions and peaks at an off-center position (r = 0.9 mm), which indicates the ring-shaped density distribution. The critical feeding gas flow rate is found to be around 0.4 SLM. The peak density is on the order of 1020 m−3 in our case. Previous reports of a flow-dependent bacterial killing pattern and ground-state atomic oxygen measurement support our simulation results.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c384fd4ea569beb17124fef2c775c337 https://doi.org/10.1088/0256-307x/32/7/075202 Zobrazit plný text záznamu