FEU-30 photoelectron multiplier operation in the key mode at nanosecond control signal duration

The problem of controlling the sensitivity of the FEhU-30 photomultipllier has been studied at a nanosecond duration of control signals. The flowsheet of the installation applied for studying the time characteristics of the FEhU control regime is considered. The dependence of the sensitivity modulation depth on the control signal amplitude and time diagrams of FEhU operation have been determined upon switching from a cut-off state to an open one. The measurements presented show that in the key regime the sensitivity modulation depth accounts for 104, the time of switching is 20 ns, a stray signal on the FEhU anode does not exceed 0.3 V at the 50 Ohm load and the amplitude of control signals equal to 140 V. A conclusion has been drawn on the applicability of the FEhU-30, operating in a key regime, for investigation of weak light fluxes, which for a time of 100 ns are preceded by a pulse light fluxes with about 104 times stronger intensity