![]() ![]() Nie straci nawet sekundy przez 200 mln lat". ^ "Uruchomiono najdokładniejszy zegar atomowy w Polsce.Institut für Experimentalphysik, Heinrich-Heine-Universität Düsseldorf. ^ "With PST, "Filipino time" is now "on time" "."Research on Cesium Atomic Clocks at the Korea Research Institute of Standards and Science". ^ Lee, Ho Seong Kwon, Taeg Yong Park, Sang Eon Choi, Sang-Kyung Park, Young-Ho (August 2004).^ "Development of Korea's First Primary Frequency Standard, 'KRISS-1' " (PDF).^ "Current activities of the National Standard Time and Frequency Laboratory of the Telecommunication Laboratories" (PDF).National Time and Frequency Standard Laboratory. The Government of the Hong Kong Special Administrative Region. ![]() ^ "History of Hong Kong Time Service".Ikegami, T., "Cesium Atomic Fountain Clocks at NMIJ" (PDF), Precise Time and Time Interval Systems and Applications Meeting, pp. 321–328, archived from the original (PDF) on "Japanese atomic clock is accurate to a 100 quadrillionth of a second". National Institute of Information and Communications Technology. Since the atoms are moving so fast, the observation time. ^ "Mission of Japan Standard Time Group - Generation of Japan Standard Time (JST)". Traditional cesium clocks measure room-temperature atoms moving at several hundred meters per second.^ "Larimer County station helps set clocks".Naval Observatory Alternate Master Clock". The National Institute of Standards and Technology (NIST). ^ "A Brief History of Atomic Clocks at NIST"."UK's atomic clock 'is world's most accurate' ". ^ "Seit wann läuft die erste Atomuhr in der PTB?".Other circuits count the atomic clock's minutes, hours, days, years, decades, centuries, millennia. When first started, the atomic clock's time is set with respect to International Atomic Time (TAI, Temps Atomique International) - which has been kept by generations of atomic clocks since 1958 when it was set relative to astronomical time. Simple electronics counts the output cycles of the quartz oscillator, and issues a pulse every 10 million cycles - exactly 1 second apart. This is a frequency standard, suitable for use in metrology, communications, and many other applications in engineering or science.Ī cesium atomic clock needs a few other parts. After the small remaining biases are measured and eliminated, the output frequency is a very accurate 10000 000 Hz, accurate to about 5 parts in one hundred thousand billion when averaged over a day. The quartz oscillator is adjusted automatically by the servo control to maximize the number of cesium ions collected, keeping the microwaves in step with the spinning of the cesium atoms. The other atoms are absorbed by another carbon getter. The B magnet deflects the in-step atoms towards a detector, the hot wire cesium ionizer and ion collector. The B magnet collects the cesium atoms that stayed in step with the microwaves, and which now have their magnetization pointing the other way (the cesium-133 atoms in the f=4 level). The spinning is stopped by the microwaves at the other end of the Ramsey cavity. (Quantum mechanics describe these cesium-133 atoms as an oscillating combination of the two hyperfine levels, f=4 and f=3.) Magnetic shielding isolates the atoms from outside magnetic fields. Allowing for tiny corrections, their magnetization spins at 9 192 631 770 rotations per second in a very uniform magnetic field, the C field of less than 1/10 the Earth's magnetic field. A cesium atomic Clock is an excellent way to backup GNSS/GPS technology for frequency, time and phase applications. Some atoms have their magnets set spinning by microwaves in the Ramsey cavity. The A magnet selects cesium atoms with their atomic magnets pointing one way (those in the f=3 level of the ground state of the cesium-133 atom), and sends other atoms to be absorbed by a carbon getter. How does it all work?Ĭesium is evaporated at the cesium source to form a beam of well-separated cesium atoms that travel without collisions at about 250 m/s, through a vacuum maintained by the vacuum pump. ![]() The clock is located in a copper room to isolate it from radio interference. Cesium atoms are emitted at one end of the tube and pass through two microwave cavities (the copper waveguide which feeds the microwaves to these cavities can be seen above the tube) before they are analyzed and detected at the other end. The large aluminium tube is a vacuum vessel which contains the heart of the clock. Officers in the Frequency and Time group, make adjustments to one of the NRC-built cesium atomic clocks. Jean-Simon Boulanger and Rob Douglas, Research ![]()
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