atomic hydrogen maser

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June 18, 2026

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An atomic hydrogen maser is a device that produces and amplifies electromagnetic radiation in the microwave range, with an output frequency so constant it can control a clock that gains or loses no more than a second over 100,000 years. Introduced in 1960, it uses hydrogen atoms in excited states, which are selected and admitted to a resonator. To improve accuracy, atoms bounce repeatedly within a storage bulb, minimizing disturbance to their frequency. This maser's fundamental frequency is approximately 1,420,405,751.77 Hz, making it a highly precise standard for timekeeping.12

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Gas masers
…frequency or time is the atomic hydrogen maser introduced by American scientists N.F. Ramsey, H.M. Goldenberg, and D. Kleppner in 1960. Its output is a radio wave whose frequency of 1,420,405,751.786 hertz (cycles per second) is reproducible with an accuracy of one part in 30 × 10¹². A clock controlled…
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…frequency or time is the atomic hydrogen maser introduced by American scientists N.F. Ramsey, H.M. Goldenberg, and D. Kleppner in 1960. Its output is a radio wave whose frequency of 1,420,405,751.786 hertz (cycles per second) is reproducible with an accuracy of one part in 30 × 10¹². A clock controlled…
Read More