Messung der Elektronendriftgeschwindigkeit in N2 und in CH4

In a homogeneous electrical field a swarm of electrons was released at the cathode by means of a short light flash. The development of the electron avalanches and their transit time were measured by photomultiplier technique. The transit timesT - and the gap distanced allows to calculate the electron drift velocitiesv −=d/T −. The drift velocities in N2 were measured in theE/p-region between 34 and 49 V/cm·Torr, in CH4 between 30 and 35 V/cm·Torr and in N2+CH4 between 33,5 and 42 V/cm·Torr.