A direct sampling RF receiver for precise beam charge measurement*

We demonstrate an RF receiver design that employs a direct digital sampling architecture. In September 2020, this receiver was installed at Jefferson Lab for its first beam test. It took signals from two beam intensity monitoring cavities on the Hall A beamline. With a 130uA beam current, it achieved 25ppm uncertainty in measuring the amplitude of a 1497MHz sinusoidal signal in a 0.5ms integration window. This device can be used for future parity-violation experiments, e.g. the MOLLER experiment to improve their beam charge uncertainties.