Qweak: A Low Noise Experiment

The Q$_{Weak}$ experiment at Jefferson Lab will make a measurement of the weak charge of the proton with a 4\% combined statistical and systematic errors using parity-violating elastic e p scattering. The main technical challenge in this precision measurement arises from the extraction of the experimental asymmetry of 0.25 ppm from the scattering rates. The primary source of error comes from the counting statistics. Strategies will be used by the collaboration to minimize the effect of other random noise that are generated by the target density fluctuations, 60Hz pick up and the electronic modules. Custom low noise electronics built for us by TRIUMF includes an 18-bit, 500kHz sampling ADC and low noise preamplifire. Performance in realistic tests will be presented.