Separated oscillatory field measurement of hydrogen 2S1/2-2P3/2fine structure interval

The 2${\mathit{S}}_{1/2\mathrm{-}}$2${\mathit{P}}_{3/2}$ interval in hydrogen has been measured using a fast atomic beam and a separated oscillatory field technique at a beam energy of 96.5 keV using standard X-band waveguides as interaction regions. The experimental value for the 2${\mathit{S}}_{1/2\mathrm{-}}$2${\mathit{P}}_{3/2}$ hydrogen fine structure interval is 9911.200(12) MHz. This implies a Lamb shift of 1057.839(12) MHz, in fair agreement with the theoretical value of 1057.866(5) MHz that was calculated using the smaller of the two discrepant values of the proton radius in the literature.