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The output charge distribution of seven channel electron multipliers was accurately measured in order to determine the influence of the count rate on the decrease of the mean gain. A law was established between secondary electron (S.E.) and conduction currents. This law holds for tubes operating in a saturated mode independent of the tube length or axial electric field strength.

The relative efficiency versus energy of a type 4028 Bendix Channeltron has been measured for electron energies in the range 10–1000 eV. A theoretical curve, derived from Lye and Dekker's theory of the secondary emission permits to derive the absolute values of the efficiency from the experimental data. Moreover the dependency of the efficiency on the operating voltage has been investigated and the experimental results are in agreement with the theoretical previsions.

The threshold of detection for charged particles is largely reduced by using a windowless channel electron multiplier. The main characteristics of this detector are: a gain higher than 10 7 , a good detection efficiency for electron between 100 eV and 40 keV, a count rate higher than 10 5 counts/sec. This detector can work independently of the pressure from 10 −3 Torr: thus its use is possible on rockets. Magnetic spectrometers can be made with channel multipliers to study the spectrum and angular distribution of auroral electrons from 100 eV to 40 keV.

The amplitude distributions and time durations of current pulses in a parallel-plate electron multiplier (PPEM) are reported. The performances of the PPEM and the channel electron multiplier (CEM) are compared and the differences in behaviour are pointed out.

The wall current and the charge distribution of a continuous channel electron multiplier are studied between 20 and 100°C. The influence of gas desorption is minimized to find the electronic structure of the emissive layer. Conduction current is characterized by an activation energy temperature dependence while mean charge analysis leads to a saturation process based on electronic conduction in a glassy solid.

We have found the useful lifetime of the channel electron multiplier during prolonged counting at moderate count rates, to be determined soley by the counting rate and operating voltage, and in the absence of any changes in these, an asymptotic value of gain can be expected to be maintained indefinitely. Electronic sensitivity criteria have also been established.

A channel electron multiplier that detects secondary electrons emitted from a thin carbon foil is the basis of a time pickoff system used for pulsed charged-particle beams in the MeV region. This system provides reliable timing reference signals for beams of a wide range of intensities.