Laser cooling and trapping of Cs-133 neutral atoms at CENAM

摘要

At the moment the National Center of Metrology (CENAM) develops to the necessary technology for the creation of a frequency standard of high accuracy denominated CsF 1 atomic fountain. The first stage of development of this clock consists of laser cooling and trapping neutral Cs-133 atoms. The mechanism of laser cooling and trapping of atoms requires of the accomplishment of a magneto-optical trap (MOT) in where is indispensable to maintain a strict control in its parameters of operation. In this experiment, the MOT operates with three set of red detuning |6~2 s_(1/2), F = 4 > → | 6~2_(3/2), F′ = 5 > cyclical transition of Cs-133, mutually orthogonal, counterpropagating laser beams, with opposite circular polarization, intersecting at the center of a magnetic field which is generated by a pair of coil in anti-Helmholtz configuration. Additionally, a beam of light that comes from a repumping laser, tuned to the frequency of the |6~2s_(1/2), f = 3 > → | 6~2_(3/2), F′ = 4 > transition of Cs-133, is injected to the MOT to maintain an atoms population in the |6~2s_(1/2), F = 4 > state. To cool and trap atoms to so low temperatures, of the order of the microkelvins on the zero absolute, by several seconds, minutes or even by several hours, provided the fundamentals tools to us to study the temporal and spatial behavior of the fluorescence of the atomic cloud and to make exact measurements in the count of such, in order to deduce the parameters of operation of the MOT that allows us to trap 10~(10) atoms or more. In this work the theoretical concepts as well as the experimental details of the parameters of operation of the MOT for the formation of the cold atom cloud are approached.