排序方式: 共有17条查询结果,搜索用时 46 毫秒
1.
M. V. Kartikeyan G. Singh E. Borie B. Piosczyk M. Thumm 《International Journal of Infrared and Millimeter Waves》2006,27(5):657-670
The feasibility of an 84 GHz, 500 kW, CW gyrotron for ECRH on an experimental tokamak will be presented in this paper. Mode
competition and mode selection procedures are carefully investigated by considering various candidate modes and the TE10,4 mode is chosen as the operating mode. A conventional cylindrical cavity resonator with weak input and output tapers and parabolic
roundings is considered for interaction studies. Self-consistent, both single mode and time-dependent, calculations are carried
out and power and efficiencies are computed for a typical set of beam parameters. The results show that an output power of
well over 500 kW, CW and efficiency around 40% can be reached without a depressed collector. 相似文献
2.
M. V. Kartikeyan E. Borie M. Thumm 《International Journal of Infrared and Millimeter Waves》2007,28(8):611-619
A design concept of a 250 GHz, ≈ 50 W, CW, second harmonic gyrotron for spectroscopy will be presented in this paper. Mode
competition, in particular with regard to competition with first harmonic modes, and mode selection procedures are carefully
investigated by considering various candidate modes and the TE6,2 and TE6,3 modes are chosen as probable operating modes. Cold cavity and self-consistent calculations of power and efficiency are carried
out to determine optimum parameters for these two modes. The results indicate that an output power of well over 50 W, CW can
be achieved. 相似文献
3.
M. V. Kartikeyan A. K. Sinha H. N. Bandopadhyay S. N. Joshi E. Borie M. Thumm 《International Journal of Infrared and Millimeter Waves》2000,21(4):553-561
In this work, the field analysis of a cylindrical interaction structure, with helical grooves, and an inner dielectric lining for possible employment in high power TWT amplifiers in the conventional slow-wave regime, is presented. The Ohmic dominance of the microwave power on the walls of this propagating circuit is deduced. 相似文献
4.
Kartikeyan M.V. Borie E. Thumm M.K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2000,28(3):645-651
We present a study of the feasibility of continuous wave (CW) operation of a 140-GHz conventional cavity gyrotron at high power levels operating in the TE/sub 31,8/- and TE/sub 25,10/-modes. The question of mode selection is discussed, and a possible design of such a gyrotron with beam energy up to 90 keV and a current of 60-70 A is given. We find that it should be possible to operate a 140-GHz gyrotron at power up to 2 MW if a sufficiently high-order mode is used, although CW power may be somewhat lower. 相似文献
5.
G. Singh M. V. Kartikeyan 《International Journal of Infrared and Millimeter Waves》2007,28(11):911-922
In this paper, we have analyzed the design parameters of the axially - extracted virtual cathode oscillator, which is high-power
microwave source based on the concept of the virtual cathode associated with the intense relativistic electrons beam oscillations
in the electrostatic potential well. The microwave emission by the virtual cathode oscillator results from both the space
and time oscillations of virtual cathode and reflexing electrons trapped in the potential well between the virtual and real
cathodes. In the X-band frequency spectrum 700 MW microwave peak power has been obtained analytically by the solid electron
beam of 300 kV and 20 kA for feasible design parameters. The analysis has been performed by 2-dimensional, relativistic, electromagnetic
particle-in-cell simulation code XOOPIC. 相似文献
6.
Collective behavior of cortico-thalamic circuits: Logic gates as the thalamus and a dynamical neuronal network as the cortex 下载免费PDF全文
Alireza Bahramian Sajjad Shaukat Jamal Fatemeh Parastesh Kartikeyan Rajagopal and Sajad Jafari 《中国物理 B》2022,31(2):28901-028901
This paper introduces a two-layer network to investigate the effects of cortico-thalamic circuits on the cortex's collective behavior. In the brain, different parts of the cortex collaborate to process information. One of the main parts, which is the path of different cortex contacts, is the thalamus whose circuit is referred to as the "vertical" cortico-thalamic connectivity. Thalamus subnuclei can participate in the processing of the information that passes through them. It has been shown that they play the functional role of logic gates (AND, OR and XOR). To study how these thalamus circuits affect the cortical neuron behavior, a two-layer network is proposed wherein the cortex layer is composed of Hindmarsh-Rose models and the thalamus layer is constructed with logic gates. Results show that considering these logic gates can lead the network towards different synchronization, asynchronization, chimera and solitary patterns. It is revealed that for AND-gate and OR-gate, increasing the number of gates or their outputs can increase and decrease the network's coherency in excitatory and inhibitory cases, respectively. However, considering XOR-gates always results in the chimera state. 相似文献
7.
G. Singh M. V. Kartikeyan G. S. Park 《International Journal of Infrared and Millimeter Waves》2006,27(3):333-342
Theoretical investigation of the peak-gain and 3-dB bandwidth of the vane-loaded gyro-traveling wave tube (gyro-TWT) amplifier
in the small-orbit TE01 waveguide mode configuration at 35 GHz has been presented. The vane-loaded gyro-TWT enjoys higher gain and bandwidth compared
to that of the smooth-wall device. In the analysis, the azimuthal harmonic effects generated due to the angular periodicity
of vanes in the wedge-shaped metal vane-loaded cylindrical waveguide interaction structure have been taken into account in
the cold (beam-absent) dispersion relation only. 相似文献
8.
G. Singh M. V. Kartikeyan A. K. Sinha B. N. Basu 《International Journal of Infrared and Millimeter Waves》2002,23(4):517-533
In this paper, the dispersion relation for a vane-loaded cylindrical waveguide, considering the azimuthal harmonic effects arising from the azimuthal periodicity of the vanes, excited in transverse electric (TE) modes and the gain for a gyro-TWT have been presented. The effects of beam and magnetic field parameters on two highly competing modes have been studied. 相似文献
9.
A highly selective and sensitive spectrophotometric procedure for the determination of cadmium is developed. This is based on the interaction of rhodamine 6G with tetraiodocadmate (II) anion to form a pink product which absorbs maximally at 575 nm that is stable for 24 hr when stabilized with gelatin. Cadmium concentrations as low as 0.01 ppm can be readily determined. The method is precise and has been applied to synthetic sea water samples and high purity zinc materials. 相似文献
10.
Arun Kumar M. V. Kartikeyan 《International Journal of Infrared and Millimeter Waves》2007,28(1):13-23
A circularly polarized stacked patch microstrip antenna and a 2 × 2 subarray for circular polarization are proposed in this
paper. The proposed design has the input impedance bandwidth and axial ratio bandwidth of about 10% and 4.7% respectively.
Circular polarization is obtained with the help of slits cut in the patch. A size reduction of around 37% is also achieved
with the help of the slits. A subarray based on sequentially rotated feeding technique for circular polarization is also presented
in this paper. Array element was deigned using a high dielectric constant laminate for feed network. In addition to low boresight
axial-ratio, the subarray has impedance and 3-dB axial-ratio bandwidths of 12% and 8% respectively. 相似文献