Abstract
We report a numerical simulation of the action of the one(_^85)Rb atom micromaser which shows that the micromaser field evolves towards a steady state equilibrium when the condition that T_p≫ t_int satisfies. In this steady state regime the cavity field reaches a steady state after a sufficient number of atoms have passed through the cavity. The cavity temperature T and the cavity quality factor Q can produce a quantitive change when one of them or the two are changed but they are not responsible for the qualitative changes in the micromaser field. Evidently the only responsible parameter for these qualitative changes is the repetition time T_p namely if T_p≫ t_int then the micromaser field evolution is towards a steady state equilibrium. In contrast when T_p reduced to the order of t_int then the micromaser field evolution is controlled by the trapping state dynamics – no steady state is apparent in this case. The first going-up trapping state at n=3 plays a significant role in the early dynamics of the micromaser field . Moreover the state of the field ultimately evolves towards a mixed state rather than a pure state.