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The superconducting spoke cavity has been proposed to accelerate the proton in the low energy section of the high power proton linac for the Accelerator Driven Sub-critical System in China. In this paper, the basic geometric and RF parameters of a β=0.3, 352 MHz spoke cavity are given, and the Lorenz detuning and tuning are presented. 相似文献
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The RF and mechanical coupled analyses are essential in superconducting cavity design in order to predict the deformation of the cavity walls and the frequency shift caused by the deformation. In this paper, the detuning caused by both bath helium pressure and Lorentz force is analysed and a tuning system has been investigated and designed to compensate the detuning by deforming the half-wave resonator along the beam axis. The simulations performed with ANSYS code show that the tuning system can adjust and compensate the frequency drift due to external vibrations and helium pressure fluctuation during operation. 相似文献
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北京大学正在设计=0.09, 频率为162.5 MHz taper型的二分之一波长射频超导谐振腔(HWR腔), 这种腔针对高流强质子束(约100 mA)和氘束(约50 mA)的加速而设计。对于这种超导腔而言机械性能分析是十分重要的, 可以通过机械性能分析来估计由于腔体的形变带来的频率偏移。用ANSYS分析了由于液氦压力不稳定造成的麦克风效应以及洛伦兹力造成的腔体失谐, 并且对沿腔体轴线方向的调谐进行了分析。模拟结果显示这只腔压力敏感系数为31.1 Hz/kPa, 洛伦兹力系数为-0.41 Hz/(MVm-1)2。 腔体的调谐范围达到177 kHz, 足够补偿腔体可能的频率偏移。腔体的机械性能满足腔体正常运行的要求。 相似文献
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The superconducting spoke cavity has been proposed to accelerate the proton in the low energy section of the high power proton linac for the Accelerator Driven Sub-critical System in China. In this paper, the basic geometric and RF parameters of a β=0.3, 352 MHz spoke cavity are given, and the Lorenz detuning and tuning are presented. 相似文献
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在正方格二维光子晶体结构中设计了基于可调谐谐振腔的带通滤波器,通过改变1×5谐振腔侧边调谐介质柱位置调节谐振腔与波导系统工作时传输的波段,用CMT理论分析了输入端耦合衰减率及输入端失谐因子对滤波器的影响。借助FDTD方法得到了滤波器波长传输谱,结果表明:当滤波器结构工作于1320~1810 nm波长段时,输出端38个通帯的-3 dB带宽Δλ范围为4.18~11.15 nm,通带峰值波长可调宽度为186.56 nm。该微型滤波器适于光电通信粗波分解复用WDDM系统设计和光集成设计等方面。 相似文献
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FELiChEM is an infrared free electron laser(FEL) facility currently under construction, which consists of two oscillators generating middle-infrared and far-infrared laser covering the spectral range of 2.5–200 μm. In this paper, we numerically study the output characteristics of the middle-infrared oscillator with accurate cavity length detuning. Emphasis is put on the temporal structure of the micropulse and the corresponding spectral bandwidth.Taking the radiation wavelengths of 50 μm and 5 μm as examples, we show that the output pulse duration can be tuned in the range of 1–6 ps with corresponding bandwidth of 13%–0.2% by adjusting the cavity length detuning.In addition, a special discussion on the comb structure is presented, and it is indicated that the comb structure may arise in the output optical pulse when the normalized slippage length is much smaller than unity. This work has reference value for the operation of FELiChEM and other FEL oscillators. 相似文献
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A cesium telluride (Cs2Te) photocathode with a quantum efficiency of 13% at 253.7 nm (radiant incidence 200 μ/cm2) is fabricated by tellurium and cesium vapor deposition onto a stainless-steel substrate. The cesium telluride cathode will be used to provide a high-brightness electron beam source for the 3+1/2 photo-injector at Peking University. The design of the system, the fabrication procedures and the preliminary experimental results are presented in this paper. 相似文献
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The influences of dipole--dipole interaction and detuning on the sudden death of entanglement between two atoms in the Tavis--Cummings model
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The influences of dipole--dipole interaction and detuning on the
entanglement between two atoms with different initial tripartite
entangled W-like states in the Tavis--Cummings model have been
investigated by means of Wootters' concurrence, respectively. The
results show that the entanglement between the two atoms can be
enhanced via appropriately tuning the strength of dipole--dipole
interaction of two atoms or the detunings between atom and cavity,
and the so-called sudden death effect can be weakened
simultaneously. 相似文献
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In this paper we study the atom dissipation effect in a laser cavity. The cavity field mode is described by the Fox- Li quasimode due to the leakiness of the cavity. Our results show that the atom decay rate versus the decay rate of the quasimode is a Lorentz type. Effects of the atom-cavity detuning as well as cavity size are also discussed. 相似文献
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光阴极注入器型能量回收射频加速器(PERL)是新一代加速器,在高平均功率自由电子激光和下一代高亮度光源等研究中有很好的应用前景。分析了PERL的强流与高平均功率特性,对注入器输出束流品质的要求及光阴极注入器、超导加速腔等关键技术进行了研究,设计分析了一种特殊结构的高压DC Gun光阴极注入器,能有效地提高DC加速腔中的加速场强,当高压为1MV和加速场达到10MV/m时,产生的电子束流能够基本满足PERL应用要求。同一超导加速段中的束流加速和能量回收的数值模拟计算结果表明,能获得高效率电子束流能量回收效果。 相似文献
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An analytical solution for a master equation describing the dynamics of a qubit interacting with a nonlinear Kerr-like cavity through intensity-dependent coupling is established. A superposition of squeezed coherent states is propped as the initial cavity field. The dynamics of the entangled qubit-cavity states are explored by negativity for different deformed function of the intensity-dependent coupling. We have examined the effects of the Kerr-like nonlinearity and the qubit-cavity detuning as well as the phase cavity damping on the generated entanglement. The intensity-dependent coupling increases the sensitivity of the generated entanglement to the phase-damping. The stability and the strength of the entanglement are controlled by the Kerr-like nonlinearity, the qubit-cavity detuning, and the initial cavity non-classicality. These physical parameters enhance the robustness of the qubit-cavity entanglement against the cavity phase-damping. The high initial cavity non-classicality enhances the robustness of the qubit-cavity entanglement against the phase-damping effect. 相似文献
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We investigate the dynamics of palrwise quantum discord (QD) for a mixed three-qubit W-type state in three independent non-Markovian reservoirs at zero temperature, each of which is modeled by a leaky cavity with Lorentzian spectral density. The influence of the environment's amount of non-Markovianity, the detuning between the qubit frequency and the cavity centre frequency, and the purity of the initial state on the QD dynamics are analyzed in detail. It is found that in the non-Maxkovian regime the system-reservoir interactions induce QD revivals and oscillations no matter whether the detuning is zero or not. Moreover, QD can be preserved for a long time if the non-Markovian condition and the detuning condition are satisfied simultaneously. 相似文献
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The problem of regimes of an active interferometer—a cavity with an amplification cell, excited by an external signal—is solved for the case in which the frequency of the cavity is modulated. If the modulation frequency is larger than the phase-matching bandwidth, upon tuning the cavity frequency, there are ranges of detuning where the mean beat frequency is constant and proportional to the modulation frequency, and peaks of width proportional to the phase-matching bandwidth arise in the output power in these detuning ranges. 相似文献
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We study the dynamics of the multipartite systems nonresonantly interacting with electromagnetic fields, focusing on the large detuning limit for the effective Hamiltonian. Due to the many-particle interference effects, the more rigorous large detuning condition for neglecting the rapidly oscillating terms for the effective Hamiltonian should be N 1/2 g, instead of g usually used in the literature even in the case of multipartite systems, with N the number of microparticles involved, g the coupling strength, the detuning. This result is significant since merely the satisfaction of the original condition will result in the invalidity of the effective Hamiltonian and the errors of the parameters associated with the detuning in the multipartite case. 相似文献
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Dependence of the coupling strength of two-wave mixing gain in photorefractive materials for the single unidirectional ring resonator on oscillation conditions has been analyzed in the strong nonlinear regime. In this regime, difference between the frequency of the pump beam and oscillating beam is proportional to the cavity-length detuning, which can be explained in terms of the photorefractive phase-shift. This phase-shift results due to slightly non-degenerate two-wave mixing that compensates for cavity detuning and satisfies the round-trip phase condition for the steady-state oscillation. The presence of such a phase-shift allows the possibility of the nonreciprocal steady-state energy transfer between the pump and oscillating beams. If the gain due to the beam coupling is large enough to overcome the cavity losses then the signal beam is amplified in the presence of material absorption. Such amplification is responsible for the oscillations. For the single unidirectional ring resonator, the effects of cavity-length detuning, energy coupling coefficient, crystal thickness of the material, reflectivity of the cavity mirrors and material's absorption coefficient on the frequency and intensity of oscillations have also been studied in detail. It has been found that for the smaller value of absorption coefficient (α) of the photorefractive crystal, the unidirectional ring resonator can oscillate at almost any cavity-length detuning (ΔΓ) whereas for the larger value of α oscillation occurs only when the cavity-length detuning is limited to small region (around ΔΓ=0). But reverse of the case is found for energy coupling coefficient (γ0). 相似文献