Suren Kandasamy Dissertation.pdf - University of Surrey

M.Sc Dissertationoperated at – 1800 Volts. Then 60 Co source was placed middle of the two BaF 2 detectorfront paces. The distance between the source and one detector was kept as 8 cm.The output of the each detector taken as two channels representing the fastchannel (anode or timing channel) and the slow channel (dynode or energy channel).The fast channel signal was connected to an ORTEC 934 EG&B constant fractiondiscriminator (CFD), while the energy channel signal was connected to the Canberra2022 shaping amplifier. Then the both signals were recorded using digital oscilloscope,which was triggered in a qualified mode incorporating level crossing of both signals,effectively acting as a coincidence gate to make sure they are in coincidence and passedto the MCA to adjust the CFD window to accept the 1173.24 keV peak only. Then theoutputs of the CFD were connected to the start and stop of the ORTEC 566 time-toamplitudeconverter (TAC) with the range of the TAC set at 50 ns. Finally, output ofthe TAC was connected to the input of an ORTEC (8192 channel) MCA, and the pulseheight spectrum was analysed using ORTEC Maestro for windows software [11].Then BaF 2 scintillator in the stop channel was replaced with the size of 44.450.8mmLaCl 3 :Ce(10%) scintillator directly coupled with Hamamatsu R6231photomultiplier tube operated at +950 Volts. Then the above step was done withLaCl 3 :Ce-BaF 2 detector. To obtain the time resolution in time scale (ps) the MCAsystem was calibrated using nanosecond delay at the stop signal.K. Suren 16