The Atomic Physics Laboratory was established in 2015 within the framework of a National Project funded by the Italian Ministry for Education and Research (PRIN2015 call, project n. 0152MRAKH, entitled «A new primary method of gas thermometry based upon Doppler-broadened mercury spectroscopy in the UV region»).
The laboratory is devoted to precision measurements in atomic systems, with two main missions:
1. Development of Doppler broadening thermometry in atomic gases for the practical realization of the new kelvin;
2. Producing high quality atomic data for applications to Astrophysics.
The first activity is performed in collaboration with INRIM in Torino and INO-CNR in Florence. It is aimed to develop a primary gas thermometer based upon Doppler broadening thermometry (DBT). This method represents an optical route to the thermodynamic temperature that consists in measuring the Doppler width of a spectral line in atomic or molecular gas samples at the thermodynamic equilibrium. Past literature shows a few examples of DBT implementations in which low-pressure alkali-metal vapors have been used as thermometric substance. We propose mercury as the ideal candidate to perform DBT for a number of favorable reasons. The current limitations of DBT are likely to be overcome by observing very precisely the shape of the intercombination transition in mercury vapors at 253 nm. This line is normally used for laser cooling of Hg atoms.
Regarding the second activity, we intend to improve the current capabilities of laser spectroscopy to produce high-quality atomic data of astrophysical interest, with a particular focus on lifetimes, transition probabilities and absolute line center frequencies. High resolution and high precision spectroscopy is performed in laboratory plasmas, combining the technology of self-referenced optical frequency combs in the near-infrared with the most advanced techniques of non-linear optical mixing and non-linear spectroscopy. Within the framework of the V:ALERE Program (funded by University of Campania “Luigi Vanvitelli”), we have started a Laboratory Astrophysics Atomic Spectroscopy Program, in the ultraviolet-visible region, with the ambitious goal to provide a significant contribution to the satisfaction of the currents needs of the Astronomy community.
The Group is also part of the FAMU collaboration, since 2017, funded by INFN (National Institute for Nuclear Physics).