A simple method for measuring transition efficiencies of weak-field radio frequency transition units for polarized atomic hydrogen sources

A weak magnetic field radio frequency transition unit (RFT) was developed a nd installed in a compact atomic-beam type polarized ion source. A simple e xperimental method was devised to determine the transition efficiency of th e RFT without ionizing and/or accelerating of the atomic beam. This method is based on the switching operation of the RFT generating the difference in the atomic beam intensity. The measurement of the atomic beam intensity an d the calculation of the acceptance for each stale of the atom in the atomi c bean system allow us to determine the transition efficiency of the RFT. T he experimental transition efficiency of the RFT for hydrogen atoms mas 0.8 8. For studying the validity of this method, the transition efficiency was calculated bi solving a time-dependent Schrodinger equation by considering the actual magnetic field distribution in the RFT. The calculation results reproduced the experimental data within about 10% error.