Electronic excitation temperature profiles in an air microwave plasma torch

被引:128
作者
Green, KM [1 ]
Borrás, MC [1 ]
Woskov, PP [1 ]
Flores, GJ [1 ]
Hadidi, K [1 ]
Thomas, P [1 ]
机构
[1] MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA
关键词
atmospheric pressure plasma; atomic emission spectroscopy; electronic excitation temperature; microwave plasma;
D O I
10.1109/27.922753
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
A 0.9- to 1.5-kW 2.45-GHz atmospheric pressure air microwave plasma torch has been operated efficiently with less than 1% reflected power. The plasma is sustained in a 28-mm internal diameter fused quartz tube, which penetrates perpendicularly through the wide walls of a tapered and shorted WR-284 (72 x 17-mm cross section) waveguide. A study has been made of the effects of power and airflow on the electronic excitation temperature, T-exc. Abel inversion of radial profile chord averaged Fe I emission lines in the 370-377-nm range have been used to obtain localized profile measurements of T-exc inside the waveguide excitation region. In general, temperature profiles peak on axis with no evidence of a skin effect in the large diameter (10-mm full width at half maximum emission intensity) plasmas. A maximum central T-exc of 6550 K +/- 350 K is observed at an airflow rate of 28 Ipm, When maintaining a constant flow rate of 14 Ipm, a 55% increase in microwave power from 0.9 to 1.4 kW causes a similar to 100% increase in plasma volume without any noticeable effect on the central T,,, value. At a constant microwave power of 1.4 kW, an increase in total flow rate from 11 to 28 Ipm decreases the volume of the plasma by similar to 25% and increases the central T-exc by similar to 13%. The axially peaked temperature profiles are consistent with an electron density of similar to 10(13) cm(-3).
引用
收藏
页码:399 / 406
页数:8
相关论文
共 26 条
[1]   COMPARISON OF TEMPERATURE-MEASUREMENTS IN ICP AND MIP WITH AR AND HE AS PLASMA GAS [J].
ABDALLAH, MH ;
MERMET, JM .
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY, 1982, 37 (05) :391-397
[2]   BEHAVIOR OF NITROGEN EXCITED IN AN INDUCTIVELY COUPLED ARGON PLASMA [J].
ABDALLAH, MH ;
MERMET, JM .
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER, 1978, 19 (01) :83-91
[3]   ELECTRONIC EXCITATION AND IONIZATION TEMPERATURE-MEASUREMENTS IN A HIGH-FREQUENCY INDUCTIVELY COUPLED ARGON PLASMA SOURCE AND THE INFLUENCE OF WATER-VAPOR ON PLASMA PARAMETERS [J].
ALDER, JF ;
BOMBELKA, RM ;
KIRKBRIGHT, GF .
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY, 1980, 35 (04) :163-175
[4]  
BORRAS MC, 1998, 1998 IEEE INT C PLAS, P169
[5]   THE INDUCTIVELY COUPLED RF (RADIO-FREQUENCY) PLASMA [J].
BOULOS, MI .
PURE AND APPLIED CHEMISTRY, 1985, 57 (09) :1321-1352
[6]  
BOUMANS PWJ, 1987, CHEM ANAL, V90, pCH10
[7]   Experimental investigation of large-volume PIA plasmas at atmospheric pressure [J].
Brandenburg, JE ;
Kline, JF .
IEEE TRANSACTIONS ON PLASMA SCIENCE, 1998, 26 (02) :145-149
[8]   PHYSICAL AND ANALYTICAL ASPECTS OF A MICROWAVE EXCITED PLASMA [J].
FALLGATTER, K ;
SVOBODA, V ;
WINEFORDNER, JD .
APPLIED SPECTROSCOPY, 1971, 25 (03) :347-+
[9]  
FLORES GJ, 1998, THESIS MIT CAMBRIDGE
[10]   COMPARISON OF MICROWAVE-INDUCED PLASMA SOURCES [J].
FORBES, KA ;
RESZKE, EE ;
UDEN, PC ;
BARNES, RM .
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, 1991, 6 (01) :57-71