A tokamak plasma has electron density

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 tokamak plasma has electron density ne=3.0×1019 m−3n_e = 3.0\times10^{19}\,\mathrm{m^{-3}}, electron temperature Te=3.0 keVT_e = 3.0\,\mathrm{keV}, and ln⁡Λ=15\ln\Lambda = 15. A transient induced electric field of E=0.50 V m−1E = 0.50\,\mathrm{V\,m^{-1}} appears along the field lines. ((a)) Calculate the Dreicer field ED=nee3ln⁡Λ/4πϵ02TeE_D = n_ee^3\ln\Lambda/4\pi\epsilon_0^2T_e. ((b)) Calculate the relativistic critical field Ec=nee3ln⁡Λ/4πϵ02mec2E_c = n_ee^3\ln\Lambda/4\pi\epsilon_0^2m_ec^2. ((c)) Decide whether runaway electrons can form, and if so from which part of the distribution.

Browse the problem library