An investigation was made of the formation a train ultrashort pulses in an yttrium aluminum garnet laser. This process found to depend strongly on ratio radiation intensities active material and nonlinear absorber. A suitable selection this increased efficiency fluctuation with highest amplitude improved considerably contrast, i.e., intensity principal the.intensity background. criterion correct conditions presence two definite thresholds, one which corresponded free oscillations other...

An investigation was made of the influence spiking on spectral characteristics injection-laser diodes. The carried out single and double GaAs diodes operating at 90°K. It found that emission spectrum obtained in non-spiking case consisted one or two longitudinal modes. Spiking characterized by a modulation depth about 50% increased number modes to three four. appearance spikes with greater gave rise five eight axial This behavior semiconductor lasers attributed excitation spikes.

Two periods of fast (covering one or two solar rotations) global variations magnetic fields have been found to exist in each 11‐year cycle activity. Solar activity that is determined from commonly employed indices (Wolf numbers, radio flux, etc.) changes little during these periods. These are characterized by both an enhancement flaring activity, which accounts for the current, and, accordingly, structures. One occurs rising phase and accompanied large‐scale structure corona. In this case,...

Problem Statement and Purpose. Generalized data on the location of freshwater molluscs families Bulinidae Herrmansen, 1846 Lymnaeidae Lamarck, 1799 Karagan, Konk, Sarmatian regions Southern Ukraine are given. The bulinids lymnaeids in Neogene other territories, as well features vertical distribution from deposits Ukraine, were described. Data&Methods. Freshwater genus Planorbarius Dumeril, 1806 (Kovalenko, Zubaneva, 2021) Lymnaea studied by us sediments Karaganski Regioyarsk (St. 29z,...

The article presents forced axial vibrations of the rotor with an automatic unloading machine in oxidizer pump. A feature design is use autoloading system slotted throttles mutually inverse throttling. Their conductivity determined by a numerical experiment ANSYS CFX software package.

The results are given of an investigation the time characteristics electron-beam-pumped GaAs sealed-enclosure laser. Spatial scanning electron beam across crystal made it possible to vary power, shape, and repetition frequency 10−10–10−6 sec laser output pulses. was achieved by a wide-band system deflecting plates grid modulation electrode.

The Monte Carlo method is used to calculate the spatial distribution of density absorbed energy and dimensions excited region in GaAs CdS semiconductor lasers by beams electrons energies from 10 keV 20 MeV. results calculations are derive an approximate analytic expression convenient for determination with depth material a wide range electron energies. A considerable reduction maximum value pump occurs when beam diameter small. This one reasons increase lasing threshold (expressed terms...

A study was made of time and spectral-time characteristics the radiation emitted from pure doped cadmium sulfide subjected to high rates excitation (1027 – 1028 cm−3sec−1) at 300 °K. The radiative transition times were determined for various recombination channels: τex = (11–12)×10−9 sec exciton mechanism accompanied by emission one or two phonons; τib 6×10−9 interband (when nonequilibrium carrier density Δn 1×1018 cm−3); τimp (1–3)×10−9 involving shallow impurities. coefficient Bib...

We discuss the issues of primary importance for understanding nature climate changes in 20th century and main physical processes responsible them. Special attention is paid to which occurred 1943–1976 2000–2014. These periods exhibit maximum increase CO2 atmosphere, with virtually unchanged global temperature its reduction some regions. study atmospheric sea surface effects solar activity. The paper deals results analysis regularities peculiarities a tropospheric response separate...

Introduction. The investigation of possibility using the slot resonators in compact microwave filters with Chebyshev characteristic is aim work. constructions on base filters-prototypes sections length λ/16 narrow rectangular microstrip line ground plane are considered. Main part. On transmission theory, fast analyzing technique such by means ABCD-matrices proposed (simple theory). numerically analyzed and experimental measurement proposed. Conclusion. According to technique, high-impedance...

An electron-beam-pumped cadmium sulfide laser was developed in the form of a sealed unit cooled with liquid nitrogen. The electron energy up to 60 keV, density electron-beam current 10 A/cm2, and radiation output 40 W. duration pulses could be varied from 10–6 10–10 sec by modulation scanning crystal beam. pulse repetition frequency beam 200 Hz 1 GHz.

To determine the fraction of 30 keV hydrogen atoms that were ionized by Lorentz force in a magnetic field up to 60 kG, we performed direct measurement, unlike experiment Sweetman who evaluated neutral flux following charge exchange. The beam was obtained from exchange proton on supersonic jet carbon dioxide vacuum residual pressure 5 × 10 −7 torr; strength, measured with small inertial calorimeter (thermocouple) calibrated an ion beam, nearly constant during pulse. Electrons removed weak...