A deuterium plasma has electron density and electron temperature .

PHYSICS · Multi-part · Fermi University Physics · Plasma Physics · Kinetic theory, collisions and transport · Kinetic theory, collisions and transport

Plasma Physics, Ch Coulomb collisions: the Coulomb logarithm, the Fokker-Planck equation and Spitzer resistivity

Problem

A deuterium plasma has electron density ne=1.0×1019 m−3n_e = 1.0\times10^{19}\,\mathrm{m^{-3}} and electron temperature Te=1.0 keVT_e = 1.0\,\mathrm{keV}. ((a)) Calculate the Debye length λD=(ϵ0Te/nee2)1/2\lambda_D = (\epsilon_0T_e/n_ee^2)^{1/2}. ((b)) For an electron-ion encounter at the electron thermal speed vte=(Te/me)1/2v_{te} = (T_e/m_e)^{1/2}, calculate the classical cutoff b90=e2/4πϵ0mevte2b_{90} = e^2/4\pi\epsilon_0m_ev_{te}^2 and the quantum cutoff ℏ/mevte\hbar/m_ev_{te}, and decide which one sets bmin⁡b_{\min}. ((c)) Hence evaluate ln⁡Λ=ln⁡(λD/bmin⁡)\ln\Lambda = \ln(\lambda_D/b_{\min}).

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