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In the active hydrogen maser, the cavity oscillates by itself. This requires a higher hydrogen atom density and a higher quality factor for the cavity. With advanced microwave cavities made out of silver-plated ceramic, the gain factor can be much higher, thereby requiring less hydrogen atom density. [ 3 ]
A hydrogen maser. The hydrogen maser is used as an atomic frequency standard. Together with other kinds of atomic clocks, these help make up the International Atomic Time standard ("Temps Atomique International" or "TAI" in French). This is the international time scale coordinated by the International Bureau of Weights and Measures.
A hydrogen maser produces a very accurate signal (1.42 billion cycles per second), which is highly stable—to one part in a quadrillion (10 15). This is equivalent to a clock that drifts by less than two seconds every 100 million years. [5] A microwave signal derived from the maser frequency was transmitted to the ground throughout the mission.
If SVG files are required, it is recommended that structure diagrams be exported as enhanced metafiles (.emf) which can be read by Inkscape and other image editors. From the "Options" menu, choose "Set Structure Drawing Style" → ACS Style; Draw the structure or reaction diagram; Export the file as PNG or EMF for further processing (see below)
Download as PDF; Printable version; In other projects Wikidata item; Appearance. ... Five caesium clocks, one passive hydrogen maser, two active hydrogen masers. [26]
Atomic clocks based on hydrogen standards are therefore regarded as secondary representations of the second. Hydrogen masers have superior short-term stability compared to other standards, but lower long-term accuracy. The long-term stability of hydrogen maser standards decreases because of changes in the cavity's properties over time.
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The site also hosts a hydrogen maser, a standard feature for radio telescopes that can also serve to receive telemetry from deep space missions. Other instruments formerly at the site included a solar -observing array of thirty-two 10 ft (3 m) dishes, and a single 1.8 m solar flux monitor observing at 10.7 cm wavelength, and an 18 m radio ...