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1.
We report on the results of a numerical investigation of the synchronization of two coupled klystron oscillators with an external feedback circuit. Simulation has been carried out using the particle-in-cell method. We have also considered the results of a numerical analysis of an amplifier klystron and an isolated klystron oscillator, which make it possible to choose the optimal values of parameters of coupled klystrons. The structure of the synchronization domain for various parameters has been analyzed. The possibility of increasing the total output power with an appropriate choice of parameter of coupling between the oscillators has been revealed. 相似文献
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J. J. Barroso K. G. Kostov J. P. Leite Neto 《International Journal of Infrared and Millimeter Waves》2001,22(2):265-276
With application to centimeter-wave monotron oscillators, the present work proposes a rippled wall cylindrical cavity that provides efficient coupling to a coaxial output circuit. Driven by a centered, solid 50 A, 34 keV electron beam, the corrugated cavity thus designed operates at 10.5 GHz in the 2-mode with two radial variations. The monotron operation is examined through 2.5D particle-in-cell simulation giving 260 kW average power output. This corresponds to 15.3 percent overall efficiency at the theoretical limit of 20.0% percent electronic effciency as predicted by one-dimensional analysis. 相似文献
3.
提出了一种新型的高功率虚阴极径向反射速调管振荡器,它结合了虚阴极振荡器容易起振和速调管微波产生效率较高的特点。利用虚阴极反射电子束对调制腔的正反馈,可以减小起振电流和起振时间,而且提高了微波产生效率。它是一种结构简单、紧凑的器件。用2.5维PIC程序对这种器件进行了数值模拟研究。得到的数值模拟结果表明,输入电压620 kV,电流25 kA,输出微波周期平均功率为2.5 GW。虚阴极振荡频率被锁定,频率为1.25 GHz。 相似文献
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Conclusions The efficiency of a two-resonator CRM oscillator is greater than that of a CRM monotron. The maximum value of the transverse electron efficiency of a two-resonator CRM is 0,87 with hard self-excitation and 0,82 with soft self-exoitation.In two-resonator CRM oscillators we can employ shorter resonators with a lower Q, and hence operate under conditions with large currents and high output power level without a substantial loss of efficiency.Adjustable feedback makes it possible to vary CRM parameters over wide limits and to achieve, e.g., better mode selection or higher efficiencies.Institute of Applied Physics, Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 22, No. 8, pp. 1011–1019, August, 1979. 相似文献
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对一个新型、紧凑、高效的电子直线加速器的加速管的设计,进行了等阻抗与等梯度两种结构的比较研究.对于使用一个5MW速调管的能量和相位经过选择的用毕束流注入到两种加速管的情况应用Parmela程序进行了模拟计算.说明宜于加工和调试的等阻抗加速管更为适宜.最后,简单地讨论了如用更高功率(如30MW?,相应加速能量约为30MeV)的速调管用毕束流作为这种新型加速器的注入束时,等阻抗加速结构除了在设计、加工、调试中的简单易行外,同时模拟结果表明整个加速管无需外加横向聚焦磁场. 相似文献
6.
为了提高相对论速调管放大器的工作频率、输出功率以及转换效率, 结合三重轴相对论速调管和多注速调管的特点, 采用三维电磁粒子模拟软件分析与设计了工作在X波段的长脉冲同轴多注相对论速调管放大器, 通过优化设计有效地抑制了X波段长脉冲相对论速调管放大器的自激振荡, 避免了脉冲缩短现象的产生, 使X波段相对论速调管放大器在长脉冲状态下能够稳定工作, 在注入微波功率为70 kW、束压为600 kV、束流为5 kA、轴向引导磁感应强度为0.8 T的条件下, 输出微波功率达到了1.23 GW, 效率为41%, 增益为42 dB. 相似文献
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提出了一种新结构的高功率径向强流速调管振荡器,该器件利用折叠式同轴谐振腔的微波场与接近空间电荷限制电流的径向电子束强烈相互作用产生高功率微波。首先对这种器件的实现机理进行了初步的分析,提出了有间隙电压情况时的径向同轴间隙的空间电荷限制电流1维近似估计模型。分析表明:对于电子束直流接近但小于直流空间限制电流的径向速调管,当有调制间隙电压时,空间限制电流要小于无调制间隙电压情况下的直流空间限制电流,径向强流电子束电流接近和超过空间电荷限制电流时会出现强烈的调制。然后用PIC程序对其特性进行了粒子模拟,在二极管输入电压500 kV、电子束电流为30 kA条件下,最终得到了峰值功率6 GW、频率1.3 GHz的微波输出。 相似文献
8.
Grapinet M Udaltsov V Jacquot M Lacourt PA Dudley JM Larger L 《Chaos (Woodbury, N.Y.)》2008,18(1):013110
We describe experimental studies of the dynamical behavior of a recently proposed electro-optic discrete time nonlinear delay oscillator. With appropriate choice of the oscillator loop parameters and external forcing of the dynamics using a pulsed laser source, the system allows for the physical realization of a high dimensional mathematical nonlinear mapping. The dynamical features observed with this new class of discrete time delay oscillator differ significantly from those observed with similar continuous time nonlinear delay feedback oscillators and reveal the intrinsic discrete time nature of the dynamics. We also discuss specific applications to chaos communications using regularly clocked binary data. 相似文献
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Harmonic lasing of low-gain free electron laser oscillators has been experimentally demonstrated in the terahertz and infrared regions. Recently, the low-gain oscillator has been reconsidered as a promising candidate for hard x-ray free electron lasers, through the use of high reflectivity, high-resolution x-ray crystals. In this Letter, it is proposed to utilize a crystal-based cavity resonant at a higher harmonic of the undulator radiation, together with phase shifting, to enable harmonic lasing of the x-ray free electron laser oscillator, and hence allow the generation of hard x-ray radiation at a reduced electron beam energy. Results show that fully coherent free electron laser radiation with megawatt peak power, in the spectral region of 10-25 keV, can be generated with a 3.5 GeV electron beam. 相似文献
11.
Jeong-Ryeol Choi 《Reports on Mathematical Physics》2003,52(3):321-329
Exact solution of the Schrödinger equation is derived for underdamped, critically damped, and overdamped harmonic oscillators with a driving force. A unitary operator transforming Hamiltonian into a simple form is introduced. The transformed Hamiltonian, represented in terms of a modified frequency ω, is identical with the Hamiltonian of the standard harmonic oscillator for the underdamped oscillator, with the Hamiltonian of a free particle for the critically damped oscillator, and with the Hamiltonian of a system with a harmonic parabolic potential for the overdamped oscillator. The eigenvalues of underdamped oscillator are discrete while those of the critically damped and the overdamped oscillators are continuous. 相似文献
12.
Middle cavities between the input and output cavity can be used to decrease the required input RF power for the relativistic klystron amplifier.Meanwhile higher modes,which affect the working mode,are also easy to excite in a device with more middle cavities.In order for the positive feedback process for higher modes to be excited,a special measure is taken to increase the threshold current for such modes.Higher modes' excitation will be avoided when the threshold current is significantly larger than the beam current.So a high-gain S-band relativistic klystron amplifier is designed for the beam of current 5 kA and beam voltage 600 kV.Particle in cell simulations show that the gain is 1.6×105 with the input RF power of 6.8 kW,and that the output RF power reaches 1.1 GW. 相似文献
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Pegna R Nobili AM Shao M Turyshev SG Catastini G Anselmi A Spero R Doravari S Comandi GL De Michele A 《Physical review letters》2011,107(20):200801
Mechanical oscillators can be sensitive to very small forces. Low frequency effects are up-converted to higher frequency by rotating the oscillator. We show that for 2-dimensional oscillators rotating at frequency much higher than the signal the thermal noise force due to internal losses and competing with it is abated as the square root of the rotation frequency. We also show that rotation at frequency much higher than the natural one is possible if the oscillator has 2 degrees of freedom, and describe how this property applies also to torsion balances. In addition, in the 2D oscillator the signal is up-converted above resonance without being attenuated as in the 1D case, thus relaxing requirements on the read out. This work indicates that proof masses weakly coupled in 2D and rapidly rotating can play a major role in very small force physics experiments. 相似文献
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We experimentally investigated spatiotemporal patterns in chains of coupled biological oscillators with boundaries and found hidden symmetric patterns that are not straightforwardly derived from explicit geometrical symmetry of the systems. We propose a model of coupled oscillators in chains with a hidden oscillator interconnecting its boundaries. The model can explain all observed patterns including the hidden symmetric ones, while other models such as discrete analogs of Neumann boundary conditions in continuous systems cannot. 相似文献
17.
The main characteristics of a delayed-feedback multiple-cavity klystron oscillator with various oscillation modes (single-frequency
oscillations, as well as regular and chaotic self-modulations) are studied experimentally. Maps of dynamic modes on the beam
current-accelerating voltage plane are presented. Basic scenarios of transition to chaos are considered. As the beam current
and amount of feedback increase, regular and chaotic oscillation modes are found to alternate in a complex manner. It is shown
that one can significantly increase the power of chaotic oscillations by appropriately tuning the control parameters. 相似文献
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文中给出了对一个新型紧凑的电子直线加速器(linac)证明原理的研究结果.在该linac中,通过偏转磁场选择特定能量和相位的大功率速调管用毕束流,然后将它们注入到加速节中,同时使速调管工作在自激振荡状态,使传统linac上的许多部件都可以省去.据此建成的linac的结构简单、维护容易、性能良好、造价经济.因此实现这种具有众多优点的新型linac将有助于linac应用的推广.要实现这样的linac有许多关键的问题需要解决.电子束团的性能参量,如能量、电流、发射度,以及速调管自激振荡的频率稳定度等都必须符合加速的要求.文中给出的计算机模拟和实验结果都表明了实现这种新型的linac的可行性 相似文献
20.
In order to get high beam quality, a RF distribution system is required, with minimal phase drifts and errors in the BEPCⅡ linac. The additional installation of phase reference cables and monitoring equipments and stable RF distribution for BEPC linac are finished. The master oscillator is chosen to offer RF signal with low phase noise and a stable phase distribution system is built to deliver RF signal to each klystron. A phase and amplitude detector is constructed to measure the phase precisely and an IΦA unit is used for a phase shifter. Control software based on EPICS is used to connect all the units of the system, and a phasing method based on BPM is adopted to optimize the phase of each klystron. Now the phasing system is installed and tested in the klystron gallery of the BEPCⅡ linac. 相似文献