The Dual Data Acquisition Systems for MOLLER at JLab*

The MOLLER (Measurement of a Lepton-Lepton Electroweak Reaction) Project is an upcoming parity-violating electron experiment at Jefferson Lab located in Newport News, VA. MOLLER is designed to measure a 33 parts per billion (ppb) scattering rate asymmetry in the electron-electron interaction (Møller scattering) to an overall uncertainty of 0.8 ppb (2.4%) at 〈Q²〉 = 0.0058 GeV/c² , making it the most precise measurement at low Q² . By comparing the asymmetry value to Standard Model predictions, the running of the weak mixing angle can be tested to high precision. To achieve this goal, MOLLER will employ two data acquisition systems (DAQs): a high-luminosity integration system and a low-luminosity counting system. The integrating system constructs the asymmetry by summing over beam helicity windows of 0.52 ms period that are combined into pseudo-random helicity patterns and must operate without any dead-time or loss. The counting system focuses on the tracking of single electron events to verify expected flux and evaluate inter-detector correlations. The design and implementation of both systems are discussed as well as their respective contribution to the precision measurement.