maser
Sign in to save300px|thumb|upright=1.7 |The first prototype ammonia maser in front of its inventor [[Charles H. Townes. The ammonia nozzle is at left in the box, the four brass rods at center are the quadrupole state selector, and the resonant cavity is at right. The 24 GHz microwaves exit through the vertical waveguide Townes is adjusting. At bottom are the vacuum pumps.]] thumb|right|260px|A hydrogen radio frequency discharge, the first element inside a #Hydrogen maser|hydrogen maser (see description below)
Article
12 sectionsContents
- History
- Technology
- Some common types
- 21st-century developments
- Uses
- Hydrogen maser
- Astrophysical masers
- Terminology
- See also
- References
- Further reading
- External links
300px|thumb|upright=1.7 |The first prototype ammonia maser in front of its inventor [[Charles H. Townes. The ammonia nozzle is at left in the box, the four brass rods at center are the quadrupole state selector, and the resonant cavity is at right. The 24 GHz microwaves exit through the vertical waveguide Townes is adjusting. At bottom are the vacuum pumps.]] thumb|right|260px|A hydrogen radio frequency discharge, the first element inside a #Hydrogen maser|hydrogen maser (see description below)
A maser is a device that produces coherent electromagnetic waves (microwaves), through amplification by stimulated emission. The term is an acronym for microwave amplification by stimulated emission of radiation. Nikolay Basov, Alexander Prokhorov and Joseph Weber introduced the concept of the maser in 1952, and Charles H. Townes, James P. Gordon, and Herbert J. Zeiger built the first maser at Columbia University in 1953. Townes, Basov and Prokhorov won the 1964 Nobel Prize in Physics for theoretical work leading to the maser. Masers are used as timekeeping devices in atomic clocks, and as extremely low-noise microwave amplifiers in radio telescopes and deep-space spacecraft communication ground-stations.