Experimental test of local oscillator-induced performance limitation for pulse-mode passive frequency standards

An experimental test of Local-Oscillator (L.O.) degradation of time-sequential passive oscillator performance was accomplished using the TAG-controlled crystal oscillator described in an accompanying paper. For this quantitative demonstration, an electronic frequency-counter discriminator replaced the trapped ion physics package in a closed-loop experiment. With a 10 second cycle time and 5 second dead time, L.O. limited stability was demonstrated in excellent agreement with theoretical calculations. The results are also in agreement with computer simulations and confirm previous noise analysis for the case of a passive standard with short pulse "Ramsey" interrogation.