THREE-CAVITY SUPERCONDUCTING OSCILLATOR FOR GRAVITY WAVE RESEARCH.

摘要

The properties and performance of a three-cavity tunnel diode oscillator operating at 600 MHz to be used at cryogenic temperature for gravitational radiation detection are described.;A method which enables one to indirectly determine the Q's and couplings for the system by pure frequency measurements of hysteretic frequency jumps was developed and used.;The properties of tunnel diodes used as active elements in cavity oscillators are discussed, as well as the design criteria for superconducting resonators to be used in frequency stabilization schemes.;Two versions of the three-cavity oscillator are described. The first one was designed for measurements devoted to understanding the behavior and properties of the system and thoroughly used for this purpose. The second was optimized for good frequency stability, compatibility with the size and frequency design restrictions. Both versions were built out of copper and the stabilizing cavity was lead electroplated.;We have analyzed the theoretical properties of the stabilization scheme, linking the performance of the oscillator to the system's parameters, namely resonators' quality factors and cavity coupling coefficients.;Preliminary results with the second version have led to frequency stabilities of (DELTA)f/f(, )<(, )10('-12) with parameters far from being optimal for high stabilization. We expect this model to perform at stability levels of (DELTA)f/f (TURNEQ) 10('-14) - 10('-15).