Title :
Progress on prototype synthesizer electronics for 199Hg + at 40.5 GHz
Author :
Nelson, C.W. ; Walls, F.L. ; Ascarrunz, F.G. ; Pond, P.A.
Author_Institution :
Nat. Inst. of Stand. & Technol., Boulder, CO, USA
Abstract :
The design and specifications of a synthesizer for the 199 Hg+ ion standard are presented. A fractional frequency stability of 5×10-15 at 100 s will be required in order to reach the fundamental linewidth imposed by the shot noise of the atomic signal. This might be achieved by first locking a low-noise 5-MHz oscillator to an active hydrogen maser. A 100-MHz oscillator can then be locked up to the 5-MHz oscillator to reduce close-in phase noise. A commercial digital synthesizer can be used to offset-lock a 100.018-MHz oscillator to the 100-MHz signal. Frequency resolution and modulation capabilities will be provided by the digital synthesizer. The 100.018 MHz will be multiplied by five, filtered, amplified, and routed through a step recovery diode. The 81st harmonic will be extracted to probe the hyperfine resonance of 199Hg+ ions. A long-term stability of 6×10-17 is expected from the first prototype
Keywords :
frequency measurement; frequency stability; frequency synthesizers; measurement standards; mercury (metal); microwave oscillators; particle traps; radiation pressure (atoms); 40.5 GHz; 5 to 100 MHz; 199Hg+ ion standard; Ramsey interrogation; atomic signal; digital synthesizer; fractional frequency stability; frequency resolution; frequency standard; hyperfine resonance; ion trap; long-term stability; modulation capabilities; prototype synthesizer electronics; shot noise; 1f noise; Frequency; Hydrogen; Masers; Mercury (metals); Oscillators; Phase noise; Prototypes; Stability; Synthesizers;
Conference_Titel :
Frequency Control Symposium, 1992. 46th., Proceedings of the 1992 IEEE
Conference_Location :
Hershey, PA
Print_ISBN :
0-7803-0476-4
DOI :
10.1109/FREQ.1992.270034
