Precision Zeeman Modulation Microwave Spectrometer

Abstract
A high-precision Zeeman modulated microwave spectrometer was developed to measure the rotational fine structure of oxygen. The transitions lie between 50 and 65 kMc. Direct measurement of the line widths was made at pressures from 20 to 500 μ. The Zeeman components were resolved and compared with the theoretical expectation for the N−=3 line. Twelve lines were measured to better than 0.01 Mc and 11-line breadth parameters were measured to 0.1 Mc/mm. Of particular interest is the use of transistor circuits to achieve design simplification and improvement.