Experimental study of unconfined surface wave discharges at atmospheric pressure by optical emission spectroscopy

Author(s)

Ridenti, M. A. ^{[1, 2]} ; Souza-Correa, J. A. ^[3] ; Amorim, J. ^{[1, 4]}

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, Inst Fis Gleb Wataghin, BR-13083859 Sao Paulo - Brazil

^[2] Lab Nacl Ciencia & Tecnol Bioetanol CTBE CNPEM, BR-13083970 Sao Paulo - Brazil

^[3] Ctr Univ Salesiano Sao Paulo UNISAL, BR-13087290 Sao Paulo - Brazil

^[4] Inst Tecnol Aeronaut, Dept Fis, BR-12228900 Sao Jose Dos Campos - Brazil

• Document type: Journal article
• Source: JOURNAL OF PHYSICS D-APPLIED PHYSICS; v. 47, n. 4 JAN 29 2014.
• Web of Science Citations: 10

Abstract

A surface wave discharge (SWD) in argon at atmospheric pressure generated by a surfatron device was studied by optical emission spectroscopy (OES). Two distinct situations were investigated; (i) a discharge plasma in open air and (ii) a discharge plasma totally confined in a quartz tube. The electron density ne, electron temperature T-e and gas temperature T-g were investigated as a function of applied power and gas flow rate. The self-absorbing method was used to estimate the population of the metastable state Ar(1s(5)). These physical quantities were determined through optical measurements along the plasma axis of symmetry. The profile of the electron density presented a maximum value under certain conditions, in contrast with typical electron density profiles of SWDs which are usually monotonically decreasing. A correlation between the electron density and the metastable state Ar(1s(5)) was found in one of these cases, suggesting that stepwise ionization from metastable states and non-local kinetics play an important role on the unexpected increase in ionization degree along the discharge. (AU)

• FAPESP's process: 08/58034-0 - Processing of sugarcane cellulose employing atmospheric pressure plasmas
• Grantee: Marco Aurelio Pinheiro Lima
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants