In this work we present a simple model to describe evaporative cooling for ultracold trapped atoms. This process is used to achieve low temperatures of the gaseous sample by removing the hottest atoms and subsequently rethermalizing the remaining atoms at a lower temperature. The model assumes a Maxwell-Boltzmann distribution of velocities in the atomic sample and allows the calculation of the temperature and the number of remaining atoms after the hottest atoms have been removed and the rethermalization has taken place. Using these expressions we simulate the process of evaporative cooling as it is usually carried out in experiments, where colder atoms are removed after each successive rethermalization.
cold atoms; evaporation; Maxwell-Boltzmann distribution
