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We describe the design and operation of the cesium frequency frame reference of fountain type CsFO2(SU), designed and manufactured at VNIIFTRI. We present the results of metrological studies that will enable us to more accurately assess the systematic frequency shifts of the frame and to refine the estimate of the unexcluded systematic bias of the cesium frequency frame of type CsFO2(SU), whose estimated value is of the order of 2.5 10–16.

The status of the upgraded system for transmission of frequency and time standard signals is described. The signals are transmitted by different means: the global satellite navigation system (GLONASS), ultralong, long, and short wave radio stations for special and other purposes, and the global internet. The areas in which this system is being developed are examined and its structure is described.

Comparative analysis of beam and cold atom frequency standards is presented and there is a short description of the principles of laser cooling for atoms and equations for their movement. Results are provided for studies directed at creating a new generation of quantum standards for frequency, i.e., a cesium fountain. The atomic resonance for cold atoms with Q of the order of 1010 is obtained by experiment. A plan is developed and the main assemblies for a frequency primary standard vacuum system in a cold atom fountain are prepared.

A highly sensitive intracavity millimeter-wave spectrometer was developed for the investigation of the absorption spectra of van der Waals complexes in a supersonic jet. The key element of the spectrometer is a tunable oscillator, called OROTRON, which generates the millimeter-wave radiation through the interaction of an electron beam with the electromagnetic field of a high quality (Q≈104) Fabry–Perot resonant cavity. This cavity consists of a movable spherical mirror and a fixed planar mirror with the periodic structure imprinted on its surface. The electron beam moves along the periodic structure of the plane mirror. This part separated from the rest of the resonator by a mica foil is kept under ultrahigh vacuum conditions. The molecular jet is injected by a pulsed valve into the other part of the resonator. The absorption in the jet is sensitively detected by measuring the electric current in a special collector circuit of the OROTRON. The spectral purity of the OROTRON radiation is 10–15 kHz providin...

The paper presents results of development programs just finished in VNIIFTRI. Some of them, such as CS fountain standard, ensemble of new H-masers and TWSTFT station, directly improved the State Time and Frequency Standard of Russia, the influence of other are expected in closest future.

The design and operation of a gas millimetre-wave spectrometer based on a tunable generator orotron are presented. The absorption cell occupies a part of the high quality (Q approximately=104) orotron Fabry-Perot cavity. The limit of sensitivity gamma min approximately=(3-5)*10-10 cm-1 has been achieved with source frequency modulation at the output band of a receiver of 1 Hz. The narrow spectral width of the orotron radiation (10-15 kHz without locking) provides the Doppler resolution of spectral lines. An absorption signal of gas under investigation is detected by variations of the collector current of the orotron. New results on rotational transition of SiH4 in a vibrational dyad v2/v4 with the absorption coefficient gamma approximately=10-8 cm-1 are briefly given as an illustration of the sensitivity of this spectrometer.

The design and operation of a gas millimeter-wave spectrometer based on a tunable generator orotron are presented. The absorption cell occupies a part of the high quality (Q approximately equals 10 4 ) orotron Fabry-Perot cavity. The limit of sensitivity (gamma) min approximately equals (3- 5)X 10 -10 cm -1 has been achieved with source frequency modulation at the output band of a receiver of 1 Hz. The narrow spectral width of the orotron radiation (10 - 15 kHz without locking) provides the Doppler resolution of spectral lines.

Problems of the flow of a quasiviscous fluid with an arbitrary rheological law over the surface of a rapidly rotating nozzle are investigated.

Depending on shear stress in the spinneret and the temperature-speed conditions in spinning, it is possible to prepare fibres of the “core-shell” type having various ratios of the viscosities of the components in them (an important rheological characteristic of a polymer optical fibre).

The internal fibre stresses govern the behaviour of the fibres during processing and in service. It was shown elsewhere /I/ that the magnitude of these stresses in the region of the first peak of the isometric heating (IH) diagram depends not only on the orientation of the macrochains but also on that of the macrostructure of the fibre. In the work reported here the relation was determined between the remaining parameters of the IH diagram, the conditions under which the polyacrylonitrile fibre was produced, and the composition of the copolymer.

A common method of studying fibre behaviour in heating is that based on isometric heating. It is well known /I/ that the stresses developing in the specimen in isometric heating depend on the mean orientation of the macromolecules but for fibres spun from a polymer solution other factors enter. The results of the investigation described here were obtained by isometric heating and are linked with the structure and properties of wet-spun polyacrylonitrile (PAN) fibres.