Critical comparison of methods for the evaluation of electron-molecule collision frequencies in crossed E and H fields

A comparison is made of two methods for obtaining information about electron-molecule collision frequencies from crossed electric- and magnetic-field investigations. Information is given to show why it is necessary to supplement the breakdown-voltage observations with reliable prebreakdown studies, in which some control is achieved over both nonequilibrium effects and the electron-loss mechanism arising from a crossed E and H (E × H) drift motion.