INFLUENCE OF LASER FLUCTUATIONS AND SPONTANEOUS EMISSION ON THE RING-SHAPED ATOMIC DISTRIBUTION IN A MAGNETOOPTICAL TRAP

We present results of numerical simulations to justify the origin of t he width in ring-shaped atomic distributions of cold atoms held in a m agneto-optical trap. We have considered the effects of laser fluctuati ons (phase and intensity) and the presence of recoil due to spontaneou s emission. The results show that the occurrence of spontaneous emissi on accounts for the existence of a width in the atomic trajectory whil e laser fluctuations only change the average value of the atomic orbit .