RadPhi TechNote
radphi-1999-601
June 16, 1999
(updated July 2, 1999)
During the first half of 1999 the Radphi experiment underwent a major upgrade in which the recoil proton detector was replaced by a scintillator hodoscope covering angles from 30to 90
in the lab, and a barrel calorimeter was added. By increasing the detector coverage both for the recoil proton and for gammas in the barrel, the experiment improves both its acceptance and its ability to discriminate background from signal events. The increase in acceptance comes at a cost of increased trigger rates and data acquisition overhead, which can offset the gains by requiring the experiment to run at lower intensity or higher dead time. This is a major concern to Radphi, whose primary physics goals require obtaining the highest statistics possible. This note summarizes what we expect for the increase in trigger rates in the upgraded detector, based upon Monte Carlo simulation.