• python
• microwaves
• lifetime
• de-excitation
• blackbody
• radio frequencies
• ARC
• Rydberg

Rydberg atoms are neutral atoms with high principal quantum number $n$. The subject of this thesis is the measurement of the lifetime of Rubidium $87$ Rydberg atoms in controlled conditions.

The lifetime of a Rydberg state is determined by two processes: the spontaneous emission and transitions towards neighbouring Rydberg states due to the blackbody radiation (BBR). We use the de-excitation technique, which is a hybrid optical and field ionization method, to measure their lifetime on a wide range of $nS$ states.

Theoretical predictions take into account BBR-induced transitions are based on Planck's formula. Finite dimensions of the apparatus can lead some deviations in the frequency distribution, in particular for wavelenghts similar to the dimensions of the experimental apparatus, resulting as a deviation of the lifetime values from theoretical predictions. The presence of a stray electric field also affects our measured lifetime values.

This work presents the first experimental data for Rubidium Rydberg atoms lifetime in the $nS$ states with $60\lesssim n \lesssim 100$ by using the de-excitation method. A ready to use Python program which simulates the time evolution of our experimental protocol is provided. Discrepancies from theoretical predictions are found and they are probably due to finite dimensions of our cell which could lead to an enhancement or a reduction of some of BBR-induced transitions.
The deviations of the lifetime value can be used hence as a sensor of BBR.