We present results of numerical simulations to justify the origin of the width in ring-shaped atomic distributions of cold atoms held in a magneto-optical trap. We have considered the effects of laser fluctuations (phase and intensity) and the presence of recoil due to spontaneous emission. The results show that the occurrence of spontaneous emission accounts for the existence of a width in the atomic trajectory while laser fluctuations only change the average value of the atomic orbit. © 1996 The American Physical Society.

• Received 16 April 1996

DOI:https://doi.org/10.1103/PhysRevA.54.2271