2004, volume 9, special issue
5-9
10-41
The results of investigations and developments made in the course of the preparatory stage of an experiment dealing with light detection and ranging of the lunar surface using a ruby laser are presented. The experiment was conducted in an effort to specify the lunar orbit parameters. Statement of the problem, general scheme of the experiment, theory of an optimum signal accumulation (for the case when the distance to the object essentially changes with the time between pulses and an average number of photons received within a pulse is much less than a unit), evaluation of the signal quantity, noise level and the time needed for getting a reliable result, the results of studies of photomultipliers and limits of potentials of a ruby laser with the Q-factor modulation are given in the paper. A ruby laser having high directivity and power of more than 10 J under conditions of Q-factor modulation, receiving and recording equipment and light detection and ranging complex on the whole are also described.
42-67
The review is presented for results of investigations
of the millimeter-band (MB) multiple-vane pulse operating magnetrons and the
continuous operating magnetron triodes and tetrodes of a millimeter and
centimeter band, which were carried out in the Usikov Institute for
Radiophysics and Electronics of NAS of Ukraine (IRE NASU) during 1955-2003, and
also results of investigations of the pulse operating MB multiple-vane
magnetrons with the secondary-emission cathodes, which were carried out in IRE
NANU during 1966-1986 and in the Radioastronomic Institute of NAS of Ukraine
(RI NASU) during 1986-2003. The peculiarities of the magnetron constructions,
operation modes, power characteristics, the conditions for a stable one-frequency
generation of the operating oscillation modes, the conditions for a doublet
stability of degenerated oscillation modes are considered. The parameters of
some pulse surface wave magnetrons (SWM) with thermionic-emission and cold
secondary-emission cathodes, and, also, of the continuous operating SWM with
thermionic-emission cathodes are given. The results of the theoretical and
experimental investigations and the use of the millimeter-band SWM are
described briefly. It is shown that, that in the frequency interval of 30-300
GHz the magnetron oscillators operating on high electromagnetic space harmonics
of non-
oscillation modes have parameters which
correspond to practical requirements. The designed MB magnetrons are not
inferior in power characteristics to the best foreign devices in the long-wave
region of MB and have no foreign analogues in the short-wave region of MB.
68-74
The millimeter and submillimeter O-type generator with wide range and higher power is presented. This is a clinotron, which has been offered in the Institute of Radiophysics and Electronics of Ukrainian Academy of Sciences. The first specimens of the clinotron have been designed under the direction of A.Ya.sUsikov in the fiftieth of past century. The way of the devices improvement from the first specimens to present one is followed.
75-85
À problem of determining the electron flow velocities averaged over the initial phases of the entrance depending on the longitudional coordinate is considered. Different possibilities of obtaining approximate analytic expressions for this function are compared. The limiting cases of small and large wave amplitude are considered. For the case of a small amplitude the analytic expression in twelfth approximation is obtained by the method of perturbation with a small parameter. The Taylor series for this function, up to 51th term is obtained. A comparison of these analytic results with those obtained by numerical computation is carried out.
86-90
A history of microwave quantum radiophysics including the main, from author’s point of view, milestones of rise and development of this direction in IRE NAS of Ukraine is stated briefly. The main results obtained in the Institute on creation of microwave quantum amplifiers are presented.
91-111
The review is devoted to works on the organic compound solution lasers. These works had been accomplished in IRE NAS of Ukraine at the initiative and aid of A.Ya.Usikov. Numerous studies of novel active media for dye lasers have been generalized in the review. The results of investigations of electrical and spectrum-energy characteristics of non-monochromatic pumping systems for these lasers have been analyzed in it as well as the researches of processes forming the spatial-angular distribution of laser radiation have been summarized.
112-120
Some new polarizing and spectral prisms for laser are described: multy-reflection crystalline plate, interference polarizing prisms of straight view, polarizing laser kuvete, bilens for analyzing of polarized light and single light pulse energy measurer.
121-127
The mode pattern of resonance oscillations of electrooptical crystals of KDP was investigated by using two methods such as holographic interferometry and polarizing optics. It was found that the theoretical solution based on the approximation of a thin plate are in a satisfactory fit to the shift oscillations which become excited in crystals of the rectangular form (odd modes). Besides there is revealed the existence of own oscillations in these crystals that can be interpreted as even modes. The conditions necessary for effective modulation of a laser ray on resonance frequencies of the crystals KDP are determined.
128-139
A review of investigation of natural lenses is presented, that was carried out in the Institute of Radio Physics and Electronics and in the Institute of Radio Astronomy of NAS of Ukraine during many years. Kharkov scientific school of “lensists” has been created using an idea of lens effect of the terrestrial atmosphere, which has been for the first time formulated by the Ukrainian Academician Alexander Yakovlevich Usikov in 1961. For many long years, the school was being headed by the honourable worker of the Ukrainian science and technology, Professor P.V.Bliokh. The methods to calculate diffraction, statistical and geometric-optical characteristics of various natural lenses in a wide wavelength range have been developed by this school. Such lenses as the Earth atmosphere, solar corona, the shadow from the Moon in solar eclipses, and gravitational lenses are discussed in the work. Many of the results of theoretical efforts have been demonstrated experimentally.
140-153
The given work is devoted to the problem of overcoming the Terrestrial atmosphere interference during astronomical observations. The interferometric image formation been proposed earlier is investigated in the work. This method is based on measuring the coherence electromagnetic field function in the optical wave band. The method advantages over the traditional method of astronomical observation using the telescope and the multi-mirror telescope of the same configuration is demonstrated on computer models. Simulated results of signal integration are also given here.
154-157
A method of constructing nonredundant element configurations on hexagonal grids based on using difference sets is stated, and the use of such constructions in radio and optical interferometers is described. Methods of building configurations ensuring complete uniform coverage of a given hexagomal domain in the spatial-frequency plane are also adduced.
158-165
It is shown that the data of drift velocities of type III radio bursts and HB components of type II ones do not contradict the idea of the low velocity electrons beam free propagation with Coulomb scattering taking into account. The results of kinetic theory lead to character mean drift velocity strongly depending upon the height of the beam origin and therefore upon the plasma density at beam’s initial position. It can substantially determine the difference between the velocities of the beams generated by the chromosphere bursts and the velocities of the beams generated by the shock waves in corona.