William V. Smith

A Microwave Secondary Frequency Standard

A method of obtaining accurate frequency markers every 90 megacycles from 2970 megacycles to above 40,000 megacycles is described. Interpolation between markers is possible by means of a calibrated standard communications receiver. The basic frequency of 10 megacycles is continuously checked against the primary frequency standard broadcast by WWV. This equipment may be used for measuring the frequencies of spectra observed in microwave spectroscopy or for accurately calibrating microwave wavemeters. A table of absorption lines providing reference frequencies between 23,000 and 40,000 megacycles is given.

Molecular Quadrupole Moments of N2 and O2

Molecular orbital calculations of the quadrupole moments of N2 and O2 have been made. Models assuming 20 percent s—p hybridization for N2 and 5–10 percent s—p hybridization for O2 give calculated quadrupole moments agreeing with those deduced from microwave line broadening data (0.27e×10−16 esu for N2 and <0.09e×10−16 esu for O2).