A New Approach to Timing: The Fast-Fast System

A dual channel constant fraction timing discriminator incorporating multiple energy windows and coincidence logic has been developed. Incorporation of energy discrimination and fast coincidence logic into the timing channel has distinct advantages in terms of system simplicity, stability and data rates. A prototype applying the F2 approach has been constructed and tested. The system gives a Co60 FWHM of ~ 210 psec at a singles rate of > 7.5 × 105 sec-1 (~ 1200 coincidences/sec).