hydrogen maser

device

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Last updated

June 29, 2026

Quick Summary

A hydrogen maser is a device that produces and amplifies electromagnetic radiation in the microwave range. It is a type of maser, a term that is an acronym for "microwave amplification by stimulated emission of radiation." The hydrogen maser is particularly known for its extreme accuracy in keeping time.

The frequency of a hydrogen maser is exceptionally stable and reproducible, making it a fundamental standard for frequency and timekeeping. A clock controlled by a hydrogen maser can maintain accuracy within about one part in 10¹⁴ for several hours, meaning it would not lose or gain more than a second in approximately 100,000 years. This precision is achieved by examining the resonance of hydrogen atoms over an extended period within a large resonator containing a storage bulb.12

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maser
Gas masers
In the hydrogen maser, hydrogen atoms are produced in a discharge and, like the molecules of the ammonia maser, are formed into a beam from which those in excited states are selected and admitted to a resonator. To improve the accuracy, the resonance of each atom is…
Read More
In the hydrogen maser, hydrogen atoms are produced in a discharge and, like the molecules of the ammonia maser, are formed into a beam from which those in excited states are selected and admitted to a resonator. To improve the accuracy, the resonance of each atom is…
Read More