1993 Fiscal Year Final Research Report Summary
Pulse Operated MIP-MASS Sectroscopy
| Project/Area Number |
04650041
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理計測・光学
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| Research Institution | Setsunan University |
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Principal Investigator |
UCHIDA Teruo Setsunan University, Faculty of Engineering, Professor, 工学部, 教授 (60029155)
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| Project Period (FY) |
1992 – 1993
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| Keywords | MIP / Plasma / Spectrochemical Analysis / Excitation Temperature / Microwave Cavity / Electron Number Density / Finite Element Method / Atomic Emission Spectrometry / Spectroscopy |
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| Research Abstract |
In this work a new Microwave Induced Plasma(MIP) source with an axially-varied bore discharge tube was developed, whiche is able to introduce liquid aerosols directly into the plasma. The resonant frequency and electric field in the MIP TM010 cavity were calculated using the finite element method. The axially-varied tube highly enhanced the electric field on the edge an the center of the plasma discharge tube.
To confirm the effect of the discharge tube newly developed, the electron number density and the plasma temperatures were measured. The result shows that the density and the temperatures were both elevated. Accordingly, the calculation seems to be qualitatively adequate.
The measurements on plasma temperatures and on electron number density were made at a variety of operating conditions. Observed temperatures and electron number density exhibit significant increase, but decrease of argon emission intensity, upon the aqueous sample introduction. Experimental results suggest that local thermodynamic equilibrium is not consistent and excitation and ionization of atomic species due to collision with high energy elactron is dominant under the operating conditions employed for the measurements.
Using the new MIP source without cooling system, a stable plasma at relatively low forward microwave power (-20W) was obtained even with direct introduction of liquid aerosols. The effects of carrier gas flow rate, plasma gas flow rate and forward power on the intensity of Cd line were measured and the most suitable operating conditions were obtaind. To evaluate the new MIP as an excitation source for atomic emission spectrometry(AES), the linear dynamic range and the detection limits for several elements were also measured.
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