Cylindrical probe in anisotropic plasma: how can we achieve reliable results?
- 1 — National Mineral Resources University (Mining University)
- 2 — National Mineral Resources University (Mining University)
Abstract
It has been demonstrated, that cylindrical probe in anisotropic plasma allows to measure only the even components of the electron velocity distribution expansion. For the first time the method for determining the odd moments of the distribution function by solving a system of ki-netic Boltzmann equations, connecting the even and odd moments ( f 0 , f 1 ); ( f 0 , f 1 , f 2 ) etc. has been developed. The method was tested in plasma of low-voltage beam discharge in helium. The experimental probe I- V traces for different orientations of a cylindrical probe with respect to the axis of symmetry of the plasma has been obtained. The moments of f 0 and f 2 has been cal-culated, f 1 moment is defined by solving the «vector» kinetic equation. The accuracy of f 1 calculation controlled by coincidence of calculated and measured values of discharge current. Theoretical and experimental values are in a good agreement.
References
- Голант В.Е. Основы физики плазмы / В.Е.Голант, А.П.Жилинский, С.А.Сахаров. М., 1977. 283 с.
- Измерение интеграла электронатомных столкновений в низкотемпературной плазме / А.П.Мезенцев, А.С.Мустафаев, В.Ф.Лапшин, В.Л.Федоров // ЖТФ. 1986. Т.56. № 11. С.2104-2109.
- Лапшин В.Ф. Метод плоского одностороннего зонда для диагностики анизотропной плазмы / В.Ф.Лапшин, А.С.Мустафаев // ЖТФ. 1989. Т.59. № 2. С.35-45.
- Мустафаев А.С. Исследование пучковой плазмы низкого давления. Процессы ионизации с участием возбужденных атомов / А.С.Мустафаев, В.Ф.Лапшин. Л., 1989. С.156-193.
- Хаксли Л. Диффузия и дрейф электронов в газе / Л.Хаксли, Р.Кромптон. М., 1977. 290 с.
- Winkler R., Braglia G.L., Hess A., Wilhelm J. Fundamentals of a technique for determining electron distribution functions by multi-term even-oder expansion in legendre polynomials. I. Theory // Beitr. Plasmophys. 1984. Vol.24. N 6. Winkler R., Braglia G.L., Hess A., Wilhelm J. Calculations of electron swarm properties in N2 at moderate values of E/N // Beitr. Plasmophys. 1985. Vol.25. N 4. P.351-378.
- Mustafaev A.S. Probe method for investigation of anisotropic EVDF. Electron kinetic and applications of glow discharges. // Edited by U.Kortshagen, L.D.Tsendin. NY & London, Plenum Press. NATO ASI Series B: Physics. 1998. Vol.367. P.531-545.
- Godyak V.A., Demidov V.I. Probe measurements of electron-energy distributions in plasmas: what can we measure and how can we achieve reliable results?// J. Appl. Phys. 2011. Vol.44. P.1-29.
- Kumar K. The physics of swarms and some basic questions of kinetic theory // Phys. Rep. 1984. Vol.112. N 5. P.321-375.
- Sinfailam A.L., Nesbet R.K. Variational calculation on electron helium scattering // Phys. Rev. 1972. Vol.46. P.2118-2129.