Nonadiabatic transition inn=2atomic hydrogen

We present an experiment studying the nonadiabatic passage of the $F=1\mathrm{}$ hyperfine component of the $2{}_{}{}^2{}_{}{}^{}S_{\frac{1}{2}}^{}{}_{}{}^{}$ metastable state of atomic hydrogen through a reversing solenoidal magnetic field. The nonadiabatic region is compared to the model field of Hight, Robiscoe, and Thorson. The measured transition amplitudes are fitted by the calculated amplitudes and the results are discussed.