Speaker
Description
Due to their complex structure, molecules are interesting systems for applications in various fields such as quantum chemistry or precision measurements. But it also implies more difficult cooling techniques than for atoms.
This experiment on Barium Fluoride (BaF) aims at decelerating a supersonic molecular beam by using the electric force on ions, which is much more intense than the dipolar force commonly used on molecules in other slowing techniques. It thus requires fewer space and weaker electric fields compared to other techniques. For instance, applying a field of a few volts/cm is enough to decrease from 600m/s to almost zero velocity the ions in about 10 microseconds and over a few millimeters.
This deceleration process is composed of three main steps: the ionization of the molecules in BaF+ or BaF-, the ions deceleration by an electric field pulse and the neutralization. Whatever the type of formed ion, it is necessary to ensure an electron capture: for the neutralization of BaF+ or for the formation of BaF- from BaF. In both cases, this process will happen through the interaction of the molecules (BaF and BaF+) with a Rydberg atom beam, for which electrons are weakly bound.
These processes will be studied experimentally by probing the internal and external states of the neutral and ionic forms of BaF as a function of the different control parameters available such as the density of Rydberg atoms, the choice of their quantum number and the initial molecular state).
