Back in May, three of the Ps Spectroscopy team had the pleasure of attending PSAS 2022, which took place at the University of Warsaw, Poland. The conference focuses on precision measurements of simple atomic and molecular systems, including the development of new experimental methods and refinement of the theoretical calculations and models.
We heard talks from groups around the world, on Hydrogen, QED theory, exotic atoms and more. David’s talk was on our recent measurements of the microwave spectroscopy of the Ps n=2 fine structure. These experiments had the highest precision to date, though they significantly disagreed with theory and produced asymmetric lineshapes (published here and here). Later, we found out that the experimental vacuum chamber was causing reflections of the microwave fields, which appear to be the cause of the observed asymmetric lineshapes and shifts (published here). Recent experiments with a smaller vacuum chamber initially seem to have reduced the reflections in the chamber leading to symmetric lineshapes, more info to come. All of the talks are available on YouTube and are well worth a watch.
Tamara and Sam both presented posters on upcoming experiments, Ramsey interferometry of Ps and THz spectroscopy of He respectively. Tamara’s poster detailed our new DC Ps beamline (now in development!) in which an energy tunable 2S Ps beam will be created via collisions with Xe gas. With this we’re aiming to perform Ramsey interferometry using two waveguides instead of one, which we anticipate will improve our microwave spectroscopy measurements greatly. Sam’s poster showed some preliminary data on the THz spectroscopy of Rydberg He atoms. We’re planning to do more measurements like this in well-defined electric fields to perform the spectroscopy between stark manifolds, but more on all of these experiments is to come.
We’d like to thank the Candela foundation and the faculty of Physics at the university of Warsaw for organizing the conference and hosting us. We’re looking forward to the next PSAS in Wuhan!