Feasibility of Special Purpose Atomic Standard
Abstract
A special-purpose frequency standard and clock has been developed, featuring a novel combination of stability and accuracy performance, shock and temperature insensitivity, instant turn-on characteristics, and the potential for low weight, power consumption, and low fabrication costs. This device should be able to fill a metrology need not satisfied by presently available atomic and quartz-crystal standards. The device is based on the well-known 3-3 transition in ammonia (about 23 GHz), which provides the frequency reference for a 0.5 GHz oscillator. This oscillator is a novel stripline transistor oscillator of high spectral purity. Its output is multiplied in one step to K-band and the resulting output is passed through a waveguide cell containing ammonia. The detected absorption feature is used to frequency lock the 0.5 GHz oscillator to line center. To accomplish this, the oscillator is frequency modulated at about 10 kHz and is locked by nulling the third harmonic of the detected output. This technique discriminates to a high degree the effects of 'background' slope pulling. In addition, pulling from the microwave cavity absorption cell is diminished by locking the cavity to the ammonia transition by nulling the fifth harmonic of the detected output. A fixed output frequency between 5 and 10 MHz is provided by direct division from 0.5 GHz.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1976
- Accession Number
- ADA042900
Entities
People
- David J. Wineland
Organizations
- National Institute of Standards and Technology