No abstract available

[en] Up to now, the production of plasma columns through the propagation of electromagnetic surface waves had been reported essentially in the microwave range (200MHz-10GHz). It is shown that such plasmas can be achieved at much lower frequencies, at least down to 27MHz. The possibility of operating this plasma both in the RF and microwave frequency range is unique as compared to the other HF produced plasma we know. It allows to optimize the plasma parameters for given applications. We also discuss methods for producing large plasma column diameters and, as an example, characteristics of a 124mm diameter, 3.7 metre long surface wave produced plasma column, are presented

[en] Two models are described whose solution is the current density in a tubular conductor that is given by the radii r_i < r_o and supplied from an ideal current source of a frequency that does not exceed 1 GHz. It has been proven that the two models are equivalent, but model 1 can practically be used only to calculate current density in a cylindrical conductor (r_i = 0). The general methods proposed are applied to several concrete examples of tubular and cylindrical conductors. The solution of examples is given in the figures. In the solution of examples, attention is devoted to problems that are connected with the realization of numerical calculation on a computer

[en] The circuit of a wideband amplifier with automatic setting of the gain as a function of the amplitudes of the investigated signals is described. The input dynamic range is approximately 10³ (6 mV - 6 V), while the output dynamic range is -4(2-8 V). The upper boundary frequency of the passband is approximately 35 MHz. The maximum transient time for automatic setting of the chosen gain is 150 nsec. The range of working temperatures is -10 to +40⁰ C

[en] In this study, we discuss the basic concept and applicability of the LC high pass filter configuration for the magnetoimpedance sensors, and examine its performance with SPICE simulation and experiment using amorphous ribbon pattern as a sensor element. Special attention is given to the sensitivity of the filter configuration. The LC filter circuit shows the output-changing ratio per 1 Oe of 5% at 50 MHz. This value is larger in 2.5 times than the output-changing ratio expected in a conventional bridge circuit with constant current excitation

[en] We report a high-speed electrical beam switching of vertical cavity surface emitting laser with a transverse coupled cavity. A high speed (sub-gigahertz) and large deflection angle (>30°) beam switching is demonstrated by employing the transverse mode switching. The angular switching speed of 900 MHz is achieved with narrow beam divergence of below 4° and extinction ratio of 8 dB. We also measured the near- and far-field patterns to clarify the origin of the beam switching. We present a simple one-dimensional Bragg reflector waveguide model, which well predicts the beam switching characteristic

No abstract available

[en] A radiosource in Cas A at 20 and 25 MHz frequencies is investigated. Cas A measurements are carried out in 1977-1978 using the URANIUM-1 interferometerr with the 42.6 km basis. The value of the vision function for the bulk of the data at the 25 MHz frequency is 0.037+-0.1, while at 20 MHz is constitutes 0.068+-0.013. The interference observations carried out at decameter waves have proved the existence of a compact source in Cas A and permitted to determine its spectrum in the 20-111 MHz range

[en] The possibility is considered that by using a pulsed rf system a substantial reduction can be made in the rf power requirement for the next generation of large storage rings. For a ring with a sufficiently large circumference, the time between bunch passages, T/sub b/, can exceed the cavity filling time, T/sub f/. As the ratio T/sub b//T/sub f/ increases, it is clear that at some point the average power requirement can be reduced by pulsing the rf to the cavities. In this mode of operation, the rf power is turned on a filling time or so before the arrival of a bunch and is switched off again at the time of bunch passage. There is no rf energy in the accelerating structure, and hence no power dissipation, for most of the period between bunches

[en] The principle and structure of a hybrid voltage divider are proposed and the calibration and experimental testing are carried out. The ideal response conditions of the divider are analyzed by using the simplified divider model, the attenuation characteristic of two-stage voltage dividing is discussed, and then an error control method is presented. Through load calibration, the pulsed voltage frequency response of the divider can be greater than 2.9 MHz with the largest pulse width of 40 μs, the attenuation ratio (or the attenuation coefficient) of 2. 60 kV/V and the measurement error of less than 5%. The divider has the merits of low cost, easy fabrication, and being capable of ns-to μs-level pulsed voltage measurement, and it can be applied to laboratory- scale pulsed power measurement. (authors)