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1.
FPGA-based amplitude and phase detection in DLLRF   总被引:1,自引:0,他引:1       下载免费PDF全文
The new generation particle accelerator requires a highly stable radio frequency(RF) system. The stability of the RF system is realized by the Low Level RF(LLRF) subsystem which controls the amplitude and phase of the RF signal. The detection of the RF signal's amplitude and phase is fundamental to LLRF controls. High-speed ADC(Analog to Digital Converter) ,DAC(Digital to Analog Converter) and FPGA(Field Programmable Gate Array) play very important roles in digital LLRF control systems. This paper describes the implementation of real-time amplitude and phase detection based of the FPGA with an analysis of the main factors that affect the detection accuracy such as jitter,algorithm's defects and non-linearity of devices,which is helpful for future work on high precision detection and control.  相似文献
2.
 在大学基础物理教材中,将用透明薄膜获得相干光的方法称为分振幅法。因此,在一些教材和教员的教学中,常说成薄膜将入射波的振幅(或强度)分割成若干部分。这种说法往往使学生(尤其是非物理专业的学生)误认为透射光的振幅和强度是不可能大于入射光的振幅和强度的。下面,我们将说明这种认识是不正确的。  相似文献
3.
刘献铎 《应用声学》1987,6(1):47-47
W.Wang and R.Carter为印刷电路板的冷却系统制成了双阶梯超声泵的原型.如图所示,它由铝振动体、PZT激励器、应力支撑铝环和不锈钢球阀构成不用高压供给系统,可对不同种类的液体,以5—10cm~3/min的泵流量工作.系统的共振频率、振幅和泵流量对泵的几何结构是敏感的,并且,振幅与泵流量也强烈地依赖于激励电压. 超声泵的特点是效率高、成本低、尺寸小、可靠性  相似文献
4.
We study the motion of a spiral wave controlled by a local periodic forcing imposed on a region around the spiral tip in an excitable medium. Three types of trajectories of spiral tip are observed: the epicycloid-like meandering, the resonant drift, and the hypocycloid-like meandering. The frequency of the spiral is sensitive to the local periodic forcing. The dependency of spiral frequency on the amplitude and size of local periodic forcing are presented. In addition, we show how the drift speed and direction are adjusted by the amplitude and phase of local periodic forcing, which is consistent with a theoretical analysis based on the weak deformation approximation.  相似文献
5.
姚成贵  何志威  占萌 《中国物理 B》2013,22(3):30503-030503
High-frequency signals are pervasive in many science and engineering fields.In this work,the effect of high-frequency driving on general nonlinear systems is investigated,and an effective equation for slow motion is derived by extending the inertial approximation for the direct separation of fast and slow motions.Based on this theory,a high-frequency force can induce various phase transitions of a system by changing its amplitude and frequency.Numerical simulations on several nonlinear oscillator systems show a very good agreement with the theoretic results.These findings may shed light on our understanding of the dynamics of nonlinear systems subject to a periodic force.  相似文献
6.
2010年普通高等学校招生全国统一考试(理综)全国卷Ⅰ中选择题的21题答案给的是B、C.但笔者认为这个答案有些问题.原题如下.【题目】一简谐振子沿x轴振动,平衡位置在坐  相似文献
7.
The J-PARC linac has three DTL tanks to accelerate the negative hydrogen ions from 3 MeV to 50 MeV. The RF phase and amplitude are adjusted for each cavity with a phase scan method within the accuracy of 1° in phase and 1% in amplitude. The experimental results show a remarkable agreement with the numerical model within a suffcient margin in the tuning of the last two DTL tanks. However,a notable discrepancy between the experiment and the numerical model is seen in the tuning of the first DTL tank. After studying with a three-dimensional multi-particle simulation,the generation of the low energy component and the pronounced filamentation are identified as the main causes of the discrepancy. The optimization of the tuning scheme is also discussed to attain the tuning goal accuracy for the first DTL tank.  相似文献
8.
B. Julia-Diaz 《中国物理 C》2009,33(12):1296-1301
Within the Excited Baryon Analysis Center we have performed a dynamical coupled-channels analysis of the available p(e,e'π)N data in the region of W ≤ 1.6 GeV and Q2 ≤1.45 (GeV/c)2. The channels included are γ*N, π*N, ηN, and ηN which has π△, pN, and σN components. With the hadronic parameters of the model determined in our previous investigations of πN→ πN reaction, we have found that the available data in the considered W ≤ 1.6 GeV region can be fitted well by only adjusting the bare γ*N → N* helicity amplitudes for the lowest N* states in P33, P11, S11 and D13 partial waves. The meson cloud effect, as required by the unitarity conditions, on the γ*N → N* form factors are examined.  相似文献
9.
利用反应显微谱仪对70 keV He2+-He转移电离过程中的出射电子进行了成像,研究了出射电子的空间速度分布特征.结果表明:电子主要集中在散射平面内;在散射平面内,电子速度分布介于零与入射离子速度Vp之间(即前向出射)且在散射离子和靶核核间轴处有一极小值,呈现出典型的双峰结构.出射电子的上述分布特征可由出射电子波函数σ振幅和π振幅的干涉进行定性解释,σ振幅和π振幅对出射电子波函数的贡献与碰撞参数相关.在小碰撞参数下,π振幅的贡献更加明显;而在大碰撞参数下,σ振幅的贡献更加显著. 关键词: 反应显微谱仪 转移电离 电子速度分布 σ振幅和π振幅干涉  相似文献
10.
We investigate the optical bistability(OB) in a duplicated two-level system contained in a ring cavity.The atoms are driven by two orthogonally polarized fields with a relative phase.The OB behavior of such a system can be controlled by the amplitude and the relative phase of the coupling field,and it is possible to switch between bistability and multistability by adjusting the relative phase.  相似文献
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