COMPUTED ELECTRON DRIFT VELOCITY IN MOIST AIR

The free electron drift velocity in air and water vapor mixtures is calculated using the average electron method. The results indicate that the electron mobility is decreased by addition of water vapor for small electric fields, and increased by additon of water vapor for large electric fields. For still larger electric fields, the change caused by addition of water vapor dwindles. The mobility increases by as much as 43 percent for 6 percent water vapor content, occurring for an Ep near 2.5 the crossover occurs at an Ep of 1.04 for 6 percent water vapor content. The maximum increase is less for smaller water vapor contents and then occurs at lower electric field strengths.