An Apparatus for Measurement of Lifetime of the Excited States of Atoms and Molecules

An apparatus developed in our laboratory for measurement of the radiative lifetime of atoms and molecules is described. Atoms are excited by a 4 keV pulsed electron beam of 2 ns duration. The photons emitted due to the decay of a level are detected by a photomultiplier tube having a favourable single photon response. The decay curve of a desired level is measured using a modified delayed coincidence method. A typical decay curve is presented