Maser Oscillators

Abstract

Two maser oscillators have been constructed and operated. The behavior of one maser has been observed under various operating conditions by comparing it with the second maser which is used as a reference standard. The expeimental setup is shown and experimental results are given. The frequency‐pulling effects of the beam and the oscillation amplitude as a function of cavity‐tuning are compared with the theoretically expected behavior. It is shown that the simple behavior predicted by theory exists only for oscillation frequencies which are well removed from line center. The theoretical curves are obtained from a new analysis which includes the velocity distribution in the beam. A comparison is made between the velocity‐distributed and uni‐velocity theories. It is shown that the introduction of the velocity distribution drops the maximum beam efficiency from 1 to 0.76 and causes a region of stability to appear in the beam frequency‐pulling function.