Main INDEX
Monthly INDEX
PREV
NEXT
User name P. Monaghan
Log entry time 06:16:05 on January 8,2005
Entry number 138478
keyword=Prescale rates and triggers
After putting in the 4cm hydrogen target, with 5uA beam, the rates in the neutron detector were greater than 3*e6 and could not be prescaled away. We lowered the current to 4uA and also turned the high voltage to the vetos OFF but still the rate was too high. We decided to prescale away the neutron detector triggers (T7) and to keep the HRS-L and Proton detector triggers (T3 and T6) at the moment. The prescalers for T3 and T6 were set to 200 to do this. However, we found that the event rate in coda was much LESS than what we expected - about 50Hz. Changing the prescalers did not help this much and we tried several different runs. Perhaps either we have a huge amount of computer deadtime or we have a problem with the DAQ; I'm open to suggestion.