The German chemist Robert Bunsen and physicist Gustav Kirchhoff discovered caesium in 1860 by the newly developed method of flame spectroscopy. It has the largest atomic radius of all elements whose radii have been measured or calculated, at about 260 picometers. Caesium-137, a fission product, is extracted from waste produced by nuclear reactors. It has only one stable isotope, caesium-133. It is the least electronegative element, with a value of 0.79 on the Pauling scale. It is pyrophoric and reacts with water even at −116 ☌ (−177 ☏). Caesium has physical and chemical properties similar to those of rubidium and potassium. It is a soft, silvery-golden alkali metal with a melting point of 28.5 ☌ (83.3 ☏), which makes it one of only five elemental metals that are liquid at or near room temperature. Ushakov, V.: Optical devices in radio engineering.Caesium ( IUPAC spelling cesium in American English) is a chemical element with the symbol Cs and atomic number 55. 400 (2002)ĭudkin, V.I., Pachomov, L.N.: Quantum electronics. Oduan, K, Gino, B.: Chronometry and basics of GPS, p. Semenov, V.V., Nikiforov, N.F., Ermakov, S.V., Davydov, V.V.: Calculation of stationary magnetic resonance signal in optically oriented atoms induced by a sequence of radio pulses. Radiotekhnika I Elektronika (Journal of Communications Technology and Electronics) 44(12), 1528–1531 (1999) Instruments and Experimental Techniques 44(2), 215–218 (2001)ĭavydov, V.V., Semenov, V.V.: Nutation line of nuclear magnetic spectrometer with a flowing sample. Management, NTV IUT 6(186), 45–52 (2013)ĭavydov, V.V., Ermak, S.V.: A quantum spectrum analyzer based on radiooptical resonance. Petrov, A.A., Davydov, V.V., Shabanov, V.E., Zaletov, D.V.: Digital frequency synthesizer for a quantum frequency standard caesium atoms – 133. KeywordsĮrmak, S.V., Semenov, V.V., Pyatyshev, E.N., Kazakin, A.N., Komartsev, I.M., Velichko, E.N., Davydov, V.V., Petrenko, M.V.: Production and research of integrated cells for compact frequency standard on the effect of coherent population trapping. Experimental research of the metrological characteristics of the quantum frequency standard on the atoms of caesium - 133 with a new functional unit showed an improvement in the daily frequency stability.
A range of generated output frequencies is expanded, and the possibility of detuning the frequency of the neighboring resonance of spectral line that makes it possible to adjust the C-field in quantum frequency standard is implemented. The theoretical calculations and experimental research showed decrease step frequency tuning by several orders and improvement the spectral characteristics of the output signal of frequency converter. The new design of frequency converter is based on method of direct digital synthesis. A new implementation of a digital frequency converter for atomic clocks is presented. One of the directions of modernization of the caesium atomic clocks is considered.
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