ELECTRON DRIFT VELOCITIES IN A MODERATE AND IN A STRONG CROSSED MAGNETIC FIELD

From energy balance considerations in the presence and absence of a crossed magnetic field and without assuming an a priori constant electron collision frequency, an equivalent reduced electric Held concept is evolved which reduces to the more familiar equivalent pressure one when the electric field is kept constant. Using the concept and assuming a Maxwellian electron energy distribution, calculation of the electron transverse and perpendicular drift velocity and their ratio tan θ is extended to a moderate and strong magnetic field for hydrogen gas. The results are in good agreement with experimental data in the electron energy range where ionization by collision occurs. It is shown numerically that average electron collision frequency values, derived from the various transport coefficients, inherently vary widely. If the average electron collision frequency is derived from a given transport coefficient, then its value still depends on the magnitude of the reduced magnetic field even when the average electron energy is kept constant. For hydrogen the variation is least (20%) in the above energy range. A now and improved method for measuring the electron collision frequency is given, based upon the equivalent reduced electric field concept. © Taylor and Francis Group, LLC.