Precision Spectroscopy of Hydrogen with a Lamb‐Shift Polarimeter Available to Purchase

A spinfilter, the most important component of a Lamb‐shift polarimeter, is used to produce a beam of metastable hydrogen (deuterium) atoms in one hyperfine state (HFS)(α1, α2 and together with the Sona transition β3). As function of a magnetic field separated transitions between the $2s1/2$ metastable Zeeman states seem to be observable as well as single transitions into the short‐lived $2P1/2$ and $2P3/2$ states. The Breit‐Rabi diagrams for these states and, therefore, the g factors can be measured with good precision. Furthermore, the hyperfine splittings and the Lamb shift can be observed as well. Application of this method to anti‐hydrogen atoms is suggested.