Simple Photomultiplier Tube Internal-Gating Method for Use in Subnanosecond Time-Resolved Spectroscopy

Abstract

We propose a simple photomultiplier tube (PMT) internal-gating method for use in the field of subnanosecond time-resolved spectroscopy. In the proposed method, we control two dynodes in the PMT by applying a gate signal whose pulse width is Tg. When controlling the mth and the n(>m)th dynodes, a resolution time Δ t is approximately given by Δ t = Tg – ( n – m)τ, where τ is a transit time of a lump of secondary electrons traveling between the two dynodes in the PMT. In principle, the resolution time Δ t shorter than the pulse width Tg of the gate signal can be easily obtained. From a fundamental performance test, we found that a subnanosecond resolution time Δ t = 0.31 ns was obtained for the case of m = 2 and n = 5. To demonstrate the effectiveness of the proposed method, we carried out a time-resolved spectroscopic measurement of emission obtained from a white-light-emitting diode (LED) driven by a nanosecond current pulse.