Nonadiabatic processes in the course of the collisions of highly excited atoms with the solid surfaces

Atomic spectroscopy is the foundation of our knowledge of the nature. Atomic spectroscopy leaded to the birth of quantum mechanics. The definition of the second, the unit of time, is based on the measurement of the frequency the atomic transition. We deal with the influence of collisions on the optical transitions in the atoms. Of special interest for us are the processes that take place at the collisions of the atoms with the walls of the cell where they are contended. These collisions perturb the atom and lead to the transition from the highly exited states into the ground state or into the other less excited states. The last process was discovered in our laboratory with the help of a extremely thin cell, the distance between the cell walls being smaller than the wavelength of the resonance atomic transition. In such a cell the atoms collide with the cell walls much more often than with each other. Hence the processes of collisions with the walls are easer to study. In the extremely thin cell, the spectral line shapes are also unusual. Their widths depend periodically on the cell thickness becoming now brighter then thinner. The last case is very attractive for the development of miniaturized sensors of magnetic fields.