A liquid hydrogen target for the precision measurement of the weak mixing angle in Møller scattering at SLAC

A 150cm long liquid hydrogen target has been built for the SLAC End Station A E158 experiment. The target loop volume is 55l, and the maximum target heat load deposited by the electron beam is ∼700W. The liquid hydrogen density fluctuation with full beam current (120Hz repetition rate, 6×1011electrons/spill) on the target is well below 10−4 level, which fulfills the requirement for a precision measurement of the weak mixing angle in the polarized electron–electron scattering process.