Ultrastable X- band traveling-wave masers

Uniformly high gain per unit length has been achieved in a comb type traveling wave maser at X-band using Czochralski grown ruby and a high-homogeneity superconducting magnet. A high stability dual channel 9GHz maser and a single channel 3 GHz maser were developed which provide gain in excess of 30 db, noise temperature less than 7.0° Kelvin, and an intrinsic tunability in excess of 800 MHz. Electronic adjustment of gain and bandwidth in both amplifiers is provided by means of magnetic field trimming coils incorporated in the superconducting magnets.