High precision LED-based light pulser for electromagnetic calorimeter monitoring system

A LED based light pulse generator for an electromagnetic calorimeter monitoring system is described. Active quenching of afterglow allows reduction of light pulse duration of up to 2 times. The number of photons is about 10/sup 9/ per pulse of 10 ns duration. Long-term instability of the light pulse intensity not worse than /spl plusmn/0.2% is obtained. The system is capable of operating in strong magnetic fields up to 3 T.