Systematic studies in a helium 2P fine structure experiment.

An improved atomic beam laser spectroscopy experiment on the helium 2P fine structure is being performed. Continued experimental work in this area[1] will hopefully encourage corresponding theoretical progress. A number of systematic checks need to be performed, the most important of which involve magnetic field corrections, laser intensity control, laser and atomic beam alignment control and detection effects. Verification of the implemented laser intensity control will be done using the atomic beam intensity. Laser and atomic beam alignment sensitivity is studied with probe laser beams from both left and right sides of the atomic beam and studying the fine structure splitting as a function of alignment. The effects of transient changes in the detector efficiency with counts can be minimized. The status of these and other systematic studies will be discussed.

[1] F. Heydarizadmotlagh et. al  Phys. Rev. Lett.132.16. 3001 (2024)