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User name M Friend
Log entry time 17:51:27 on May 3,2010
Entry number 320846
keyword=Compton neutron trigger rates
Compton neutron background trigger rates with and without the lead hut: figure 1 is the trigger rate without the lead hut (GSO out of the Compton photon beam, run 22545) -- 330kHz, figure 2 is after building the lead hut (beam going straight, run 22797) -- 310kHz. Both runs are with the lead target in, HV=-1900, 50uA.
These rates are from the DAQ itself and have a very low discriminator threshold. They are not what appears on the stripchart. The stripchart now shows a rate of 580Hz/uA (still HV=-1900, lead target in, beam going straight). Normalized rates (from the DAQ, not the stripchart) are 6.7kHz/uA before and 6.2kHz/uA after the lead hut.