Characteristics of the 3-2 Line Double-Beam Maser of N14H3 and the Precision of Frequency Comparison

The characteristics of a double-beam maser of N¹⁴H3 3-2 line were investigated. In the experiment, Zeeman effect is used for the determination of the reference frequency. The shift of the reference frequency due to a variation of 30 per cent in the ammonia pressure, that of 20 per cent in the focuser voltage or that of 10 per cent in the intensity of the perturbing magnetic field is less than one part in 10¹⁰. The variation in the traveling-wave effect by change of the effective beam intensity, both in single-beam and double-beam types, were calculated for practical use. The phase variation and noise in the frequency multiplier and the quartz oscillator were preliminarily investigated in order to improve the precision of frequency comparison between maser and quartz crystal oscillator.