Measurement of the 0.081 Mev excited state of cesium 133 when using constant fraction single channel analyzers and a comparison of the result with that found in a previous study when using conventional single channel analyzers

Abstract

In this study a coincidence circuit composed of Ortec modules with Ge(Li)-NaI(Tl) detectors was utilized. An investigation of the different fractional threshold settings of a Constant Fraction of Pulse Height Trigger was made.Two different isotopes were investigated. A sample of 22Na was used as a prompt source. The half-life of the 0.081 Mev energy levelof 133Cs was studied. This half-life has been reported as being 6.3 nsec. Results were compared with results of a previous study at Ball State University which had used a conventional single channel analyzer and had used the zero crossover point for timing purposes.The best value received for the 133Cs energy state using a slope measurement was 8.12 t 0.25 nsec. Using a centroid shift measurement the best value of the 133Cs energy state was 5.66 nsec.