A Fluorescence Emission Detector with 100 Picosecond Time Resolution

An emission telescope has been developed for studying light intensity vs. time of scintillators and Cerenkov radiators in the subnanosecond time domain. Sample excitation is achieved with 10-MeV, 50-psec pulses of electrons from the EG&G/AEC linear accelerator. Test samples are viewed by an ultrahigh speed, coaxially mounted vacuum-photodiode detector via a 6-inch spherical mirror with an effective aperture of f/l. Photodiode detector output signals are recorded by a sampling-oscilloscope, computer-of-average-transients, data-handling system. Overall time resolution of the system is 150 psec (FWHM). The resolution function is obtained from Cerenkov emission in lucite and water. The response of one typical fast fluor material is presented, showing the prompt Cerenkov emission followed by the comparably slow fluorescence rise and decay.