共查询到20条相似文献,搜索用时 15 毫秒
1.
N. S. Ginzburg V. Yu. Zaslavskiĭ N. Yu. Peskov A. S. Sergeev A. V. Arzhannikov P. V. Kalinin S. A. Kuznetsov S. L. Sinitskiĭ V. D. Stepanov 《Technical Physics》2006,51(12):1618-1623
A planar free-electron maser with a resonator consisting of a 2D entrance Bragg mirror and a 1D exit Bragg mirror is theoretically studied in the framework of a nonstationary 2D model. In such a configuration, the 2D Bragg mirror provides synchronization of the radiation emitted by a wide (compared with the wavelength) ribbon-shaped electron beam. The transverse electromagnetic energy fluxes arising in this mirror are closed through an additional coupling waveguide, which provides a single-mode single-frequency masing regime insensitive to variation of the beam parameters over wide limits. 相似文献
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T. A. Hargreaves R. P. Fischer R. B. McCowan A. W. Fliflet 《International Journal of Infrared and Millimeter Waves》1991,12(1):9-21
Several properties of the Fabry-Perot-type open resonator used in the quasioptical gyrotron (QOG) and the quasioptical induced resonance electron cyclotron (IREC) maser are derived. The electric fields of the normal modes are given for the general case of the resonator axis tilted with respect to the direction perpendicular to the electron beam axis. The ohmic quality factor and the power dissipated in the mirrors are derived, as is the energy stored in the resonator. The time dependence of the mirror heating, relevant for pulsed experiments, is also derived. The formulae are applied to an example of current relevance, the quasioptical IREC maser resonator. 相似文献
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Ginzburg NS Peskov NY Sergeev AS Phelps AD Konoplev IV Robb GR Cross AW Arzhannikov AV Sinitsky SL 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,60(1):935-945
The use of two-dimensional Bragg resonators of planar geometry, realizing two-dimensional (2D) distributed feedback, is considered as a method of producing spatially coherent radiation from a large sheet electron beam. The spectrum of eigenmodes is found for a 2D Bragg resonator when the sides of the resonator are open and also when they are closed. The higher selectivity of the open resonator in comparison with the closed one is shown. A time-domain analysis of the excitation of an open 2D Bragg resonator by a sheet electron beam demonstrates that a single-mode steady-state oscillation regime may be obtained for a sheet electron beam of width 100-1000 wavelengths. Nevertheless, for a free-electron maser (FEM) with a closed 2D Bragg resonator, a steady-state regime can also be realized if the beam width does not exceed 50-100 wavelengths. The parameters for a FEM with a 2D planar Bragg resonator driven by a sheet electron beam based on the U-2 accelerator (INP RAS, Novosibirsk) are estimated and the project is described. 相似文献
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N. S. Ginzburg V. Yu. Zaslavsky I. V. Zotova A. M. Malkin N. Yu. Peskov A. S. Sergeev A. K. Kaminsky é. A. Perel’shtein S. N. Sedykh 《Radiophysics and Quantum Electronics》2009,52(8):557-563
We consider the possibility of implementation of a free-electron maser with a two-mirror resonator composed of modified and
conventional Bragg mirrors, operated in the short-wave part of the millimeter-wave range. The use of a modified Bragg mirror
based on the traveling and quasicritical wave coupling at the input of the interaction space permits the transverse-index
selection of modes. Amplification of the synchronous co-propagating wave by an electron beam is reached mainly in the regular
part of the resonator. Even slight reflections from the conventional output Bragg cavity, which directly couples the co- and
counter-propagating traveling waves, turn out to be sufficient for generation of self-excited oscillations. It is shown that
the new scheme of a free electron maser ensures the oscillation frequency stabilization with respect to the electron-energy
variation. With the optimal choice of the parameters, the oscillation frequency is close to the cutoff frequency of a quasi-critical
wave excited in the modified Bragg structure. 相似文献
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This paper represents a brief review on some properties of cosmic masers, in particular on OH, H2O, and SiO sources. Emphasis is given to problems of radiative transfer in the maser line as well as in other lines of the
masing molecules. The importance of these effects is an essential difference to laboratory lasers.—Differences and similarities
between the radiative properties of cosmic masers and other (NLTE) sources of line emission having no population inversion
are pointed out.—Various pumping mechanisms suggested for the interpretation of the observations are summarized.
Based on an invited paper presented at the 4th Intern. Conf. on Molecular Energy Transfer (Loccum, Germany, June 30 to July
4, 1975). 相似文献
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First experimental observations are reported on stimulated coherent synchrotron radiation from highly relativistic electrons in a strong magnetic field. The experiment employed a quasioptical millimeter-wave resonator and a 6-MeV electron beam gyrating in a field of up to 25 kG. Coherent radiation at 54 GHz, corresponding to the 11th gyroharmonic, was observed and characterized. These observations demonstrate the possibility of a synchrotron resonance maser. 相似文献
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Ginzburg NS Kaminsky AA Kaminsky AK Peskov NY Sedykh SN Sergeev AP Sergeev AS 《Physical review letters》2000,84(16):3574-3577
A new type of high-selective Bragg resonator having a step of corrugation inside the interaction region was used as a microwave system for a free-electron maser (FEM). Using a LINAC LIU-3000 (1 MeV/200 A/200 ns) to drive the FEM oscillator, a single-mode single-frequency operation was achieved at a frequency of 30.74 GHz with an output power of about 50 MW, which corresponded to a record efficiency of 35% for a millimeter wavelength FEM. 相似文献
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G. A. Markov A. S. Belov V. L. Frolov V. O. Rapoport M. Parrot 《Journal of Experimental and Theoretical Physics》2010,111(6):916-920
A method for controlled excitation of a magnetospheric maser through the production of artificial density ducts by high-power
HF radio emission from the Earth’s surface has been proposed and implemented in an in-situ experiment. Artificial density
ducts allow one to affect the maser resonator system and the excitation and propagation of low-frequency electromagnetic waves
in a disturbed magnetic flux tube. The experimental data presented here were obtained at the mid-latitude Sura heating facility.
The characteristics of electromagnetic and plasma disturbances at outer-ionosphere altitudes were measured using the onboard
equipment of the DEMETER satellite as it passed through the magnetic flux tube rested on the region of intense generation
of artificial ionospheric turbulence. 相似文献
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The formation of the space-time structure of the intensity distribution for whistlers, as well as the content of the energetic electrons in the radiation belts of Jupiter, has been considered. Parametric nonlinear processes in a plasma magnetospheric maser have been analyzed. It has been shown that, owing to the azimuthal inhomogeneity of a magnetic trap in combination with the fast rotation of the planet, a component that is characterized by the periodic modulation and is independent of the azimuth coordinate is formed in the Q factor of the magnetospheric resonator. This modulation is manifested as an external force that ensures the synchronization of oscillations in the level of whistlers in individual magnetic field tubes under the global-resonance conditions. 相似文献
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Berthold-Georg Englert Nicoletta Sterpi Herbert Walther 《Optics Communications》1993,100(5-6):526-535
An experiment to determine the parity of the photon field of one privileged mode in a high-Q resonator is proposed. Even parity indicates that the photon number equals zero, two, four or any other even integer; likewise, odd parity states are mixtures of states with any odd number of photons. The parity measurement can be performed while the resonator is pumped as in standard one-atom maser operation. The time dependence of the parity expectation value is studied theoretically, and we suggest its experimental verification, which would serve as a test of the standard models describing both the relaxation of the cavity field toward thermal equilibrium and the pumping process. The connection between parity expectation values and Wigner's phase space function is recalled; the central value of the Wigner function equals twice the mean parity and it is, therefore, a measurable quantity. 相似文献
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The theory of a one-atom maser, when the atoms enter the microresonator being excited to the upper maser level from its ground state by the bichromatic laser field resonant with the two adjacent optically allowed transitions with arbitrary angular momenta, is built. This theory is applied to the investigation of the polarization properties of a one-atom maser, i.e., the dependence of the maser field characteristics on the mutual orientations of the polarization vectors of the maser field mode and of the pump laser field. New experiments are proposed to study such polarization properties, which may be performed within the framework of the experimental setup used by Professor H. Walther and collaborators [1–3]. 相似文献
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Chen C. Danly B.G. Shvets G. Wurtele J.S. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(3):149-154
The influence of the longitudinal space-charge waves of a coherently gyrophased helical relativistic electron beam on the cyclotron maser instability is investigated in a cylindrical waveguide configuration using a three-dimensional kinetic theory. A dispersion relation that includes waveguide effects is derived. The stability properties of the cyclotron maser interaction are examined in detail. It is shown that, in general, the effects of space-charge waves on a coherently gyrophased beam are suppressed in a waveguide geometry, in comparison with an ideal one-dimensional cyclotron maser with similar beam parameters 相似文献
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N. S. Ginzburg V. Yu. Zaslavskii E. V. Ilyakov I. S. Kulagin A. M. Malkin N. Yu. Peskov A. S. Sergeev 《Technical Physics》2011,56(12):1791-1801
The feasibility of using 2D distributed feedback based on 2D planar and coaxial Bragg structures for generating spatially
coherent radiation from rectilinear ribbon and tubular electron beams is studied. One-section and sectional Cherenkov masers
are analyzed. In the former design, a 2D Bragg structure acts as a resonator and a periodic slow-wave system simultaneously.
In the latter (sectional) design, radiation is synchronized in a 2D Bragg structure that is placed at the cathode end of the
interaction space and couples longitudinal and transverse (azimuthal) wave flows. The wave is amplified by the electron beam
mainly in the fairly long middle section. The output (collector) part contains a standard 1D Bragg structure that partially
reflects the amplified radiation toward the cathode and closes the feedback circuit. It is shown that dissipation introduced
into the 2D Bragg structure of the sectional design makes it possible to increase one of the transverse sizes of the system
to ∼103 wavelengths with the energy exchange efficiency and one-frequency masing mode stability remaining the same. With such an
overdimension, the millimeter-wave radiation integral power may reach a gigawatt level. 相似文献
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本文提出一种不用缓冲气体而用涂层泡的Rb87激射器的试验方案。给出了满足激射振荡要求的特定的涂层泡的设计,同时,讨论了激射器的振荡条件及予期所能获得的短期频率稳定度。最后,指出该激射器可能发展为长、短稳兼优的频标。 相似文献
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激光抽运铯束贮存泡激射器 总被引:1,自引:1,他引:0
本文提出一种铯原子束激射器的建议,其中利用了双束激光抽运选态技术和原子贮存泡方法。用密度矩阵理论分析了振荡条件,给出了激射器的振荡功率和进泡的原子束流之间的关系式。在使用TE021模腔和石腊作涂层的环状石英泡的情况下,计算了激射器的振荡功率、线宽和腔的填充因子,对激射器的短稳亦作了相应的估计。还给出了双原子束双隔离泡的此类激射器的设想。 相似文献
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V. L. Bratman N. G. Kolganov A. V. Savilov S. V. Samsonov A. É. Fedotov 《Technical Physics》2001,46(8):1001-1008
A new version of a cyclotron-resonance maser is studied theoretically and experimentally. Here, a spatially periodic helical electron beam couples traveling (autoresonance) and quasi-cutoff (gyrotron) waves of the same frequency, interacting with them at different cyclotron harmonics. The theory and early experimental results show that this maser can effectively generate a traveling wave with low quasi-cutoff wave excitation losses using a very simple feedback system. 相似文献