Assistant Professor, Institute of Plasma and Nuclear Fusion, Institute of Nuclear Science and Technology, Tehran, Iran
Abstract
Microwave interferometry which is being used in various tokamaks in the world, is considered as one of the most reliable techniques for electron density measurement of tokamaks. The simplest type of homodyne microwave interferometers is the single channel or central-chord interferometer which measures the line integrated electron density along the longest chord of the plasma cross section of the tokamak. One of the restrictions of central-chord interferometers is that they cannot determine the spatial distribution of electron density. In this paper a semi-analytic approach based on phase difference analysis, is proposed for qualitative evaluation of electron distribution in tokamaks with central-chord interferometer. According to the suggested model, several density profiles are proposed to describe the electron distribution. It is found that in high frequency ranges the trapezoidal distribution can provide a better qualitative estimation of the spatial distribution of electron density in tokomaks. The proposed model can be used as a primary analysis of the spatial distribution of electron density along with complimentary techniques such as the microwave reflectometry and multi-channel interferometers.
H. Hutchinson, “Principles of plasma diagnostics,” Cambridge university press, 1987.##
J. Hartfuss T. Geist, “Fusion Plasma Diagnostics with mm-Waves,” Wiley-VCH, 2013.##
Miyamoto, “Plasma physics and controlled nuclear fusion,” Springer, 2005.##
C. Efthimion, et. al., “1-millimeter wave interferometer for the measurement of line integral electron density on TFTR,” Rev. Sci. Instrum., vol. 56, pp. 908-910, 1985.##
Prentice, et. al., “A two color mm-wave interferometer for the JET divertor,” Rev. Sci. Instrum., vol. 66, pp. 1154-1158, 1995.##
J. A .Fessey, et. al., “Plasma electron density measurements from the JET 2 mm wave interferometer,” J. Phys. E., vol. 20, pp. 169- 174, 1987.##
Nabipour and M. Karimi, “The effect of the propagation mode of a laser wave in an interferometer diagnostics in determining of electron density of Damavand tokamak plasma and calculation of the measurement error,” J. Appl. Electrom., vol. 4, pp. 47-53, 2016. (In Persian)##
F. Chen, “Introduction to plasma physics and controlled fusion,” Springer, 2016.##
A. Bittencourt, “Fundamental of plasma physics,” Springer, 2004.##
The facility MI-1 for the determining average plasma density of Damavand tokamak, vol. I: “Common description,” RCC Kurchatov Institute: Moscow, 1995.##
The facility MI-1 for the determining average plasma density of Damavand tokamak, “Testing results of the facility MI-1 at the Damavand tokamak,” RCC Kurchatov Institute: vol. IV, Moscow, 1995.##
L. Doane, E. Mazzucato, and G. L. Schmidt, “Plasma density measurements using FM–CW millimeter wave radar techniques,” Rev. Sci. Instrum., vol. 52, pp. 12-15, 1981.##
U. Bo, et. al., “The interaction of collisional plasma with microwave,” Plasma Sci. Technol., vol. 8, pp. 535-538, 2006.##
Noori, E. (2021). Semi-Analytic Evaluation of the Electron Density Distribution of Tokamaks With Central Chord Microwave Interferometer. Applied Electromagnetics, 9(2), 81-86.
MLA
Ehsanollah Noori. "Semi-Analytic Evaluation of the Electron Density Distribution of Tokamaks With Central Chord Microwave Interferometer", Applied Electromagnetics, 9, 2, 2021, 81-86.
HARVARD
Noori, E. (2021). 'Semi-Analytic Evaluation of the Electron Density Distribution of Tokamaks With Central Chord Microwave Interferometer', Applied Electromagnetics, 9(2), pp. 81-86.
VANCOUVER
Noori, E. Semi-Analytic Evaluation of the Electron Density Distribution of Tokamaks With Central Chord Microwave Interferometer. Applied Electromagnetics, 2021; 9(2): 81-86.