Clock (luminosity) trigger

The clock trigger is used for luminosity monitoring. The idea is that we need an unbiased sample of hits in the tagger to measure the average luminosity. In principle, we could use out-of-time events in the $\pi ^o$ triggers, but these are susceptable to higher frequency beam fluctuations which can be difficult to monitor and even more difficult to correct for. The clock will be produced using a crystal oscillator. A module designed by the Hall-B fast electronics group has been built for primex which will provide $10^4$, $10^3$, $10^2$, and $10^1$ Hz signals. Primex will use the the 10kHz trigger prescaled by a factor of 10 using the Trigger Supervisor. This will give us the option of fine tuning the clock trigger rate easily from the counting house.