Polarity Effect in DC Breakdown Voltage Characteristics of Pressurized Carbon Dioxide up to Supercritical Conditions

Author

Kiyan, Tsuyoshi ; Takade, Maya ; Namihira, Takao ; Hara, Masanori ; Sasaki, Mitsuru ; Goto, Motonobu ; Akiyama, Hidenori

Author_Institution

Grad. Sch. of Sci. & Technol., Kumamoto Univ., Kumamoto

Volume

36

Issue

3

fYear

2008

fDate

6/1/2008 12:00:00 AM

Firstpage

821

Lastpage

827

Abstract

This paper deals with the effect of the polarity and gap geometry on DC breakdown voltage characteristics of a point-to-plane gap in supercritical carbon dioxide (SC CO₂) that is required to design a plasma reactor. In the experiments, the gap width d and the curvature radius of the point tip r were changed in the range of 80 to 300 mum and 50 to 170 mum respectively, and the CO₂ state was controlled within the gas, liquid, and SC phases. The experimental results showed that a remarkable polarity effect appeared under certain gap conditions. As a result, it was found that negative polarity and a higher stressed electrode are desired conditions for the dc plasma reactor since an active corona supplying rich chemical radicals appears in SC CO₂ under such conditions.

Keywords

carbon compounds; corona; free radicals; plasma chemistry; plasma density; plasma devices; CO₂; DC breakdown voltage; chemical radicals; corona discharge; density; distance 80 mum to 300 mum; gap geometry; gas phase; liquid phase; plasma reactor; point-plane gap; polarity effect; pressurized carbon dioxide; radius 50 mum to 170 mum; stressed electrode; supercritical phase; Carbon dioxide; DC discharge; corona discharge; mist; plasma reactor; polarity effect; supercritical (SC) fluid;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/TPS.2008.920229

Filename

4485015