排序方式: 共有23条查询结果,搜索用时 31 毫秒
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During the design process, multipacting effect has been taken into consideration using a 2D simulation code MultiPac and all of the corners are rounded to suppress the multipacting effect in the pill-box cavity. However, unexpected multipacting effect prevents the increase of the input power when the magnetic field of focusing coils is added after adequate conditioning and a novel method is adopted to suppress it by introducing extra coils to counteract the field. This paper focuses on the simulation of multipacting effect in different magnetic field configurations. The experimental observations and simulation results of multipacting effect are presented and details of the multipacting process are also analyzed. 相似文献
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基于围岩变形破坏原理,建立了围岩稳定极限状态方程的普遍形式,研究了响应面方法求解该方程的过程,得出经典响应面方法仅仅适用于围岩物理力学参数随机分布曲线偏度系数为零的情况。针对围岩物理力学参数统计分布曲线的复杂性,利用统计矩参数对随机变量分布曲线形态特征的控制作用,提出了抽样样本修正方法和具体计算公式,归纳了修正后响应面算法的运行程序。以某公路隧道为例,分别采用经典算法和修正后算法计算了围岩稳定可靠度,然后与蒙特卡洛模拟结果进行了对照,经典方法计算结果与准精确解的绝对误差为1.017%,修正方法的计算结果与准精确解的绝对误差为0.388%。 相似文献
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Preliminary Systematic Study of the Temperature Effect on the K—Cs—Sb Photocathode Performance Based on the K and Cs Co-Evaporation 下载免费PDF全文
It is very important to increase the quantum efficiency(QE)and prolong the lifetime of the photocathode in a variety of applications.We have succeeded in preparing a high QE cesium potassium antimonide(K-Cs-Sb)photocathode by K and Cs co-evaporation in the photocathode preparation facility.In order to better understand the effect of the substrate(photocathode)temperature on the photocathode performance,the photocathode preparation,photocathode performance degradation,photocathode performance recovery and photocathode removal are studied in detail. 相似文献
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RF deflectors can be used for bunch length measurement with high resolution. This paper describes a completed S-band traveling wave RF deflector and the bunch length measurement of the electron beam produced by the photocathode RF gun of the Shanghai DUV-FEL facility. This is the first time that such a transverse RF deflector has been developed and used to measure the bunch length of picosecond order in China. The deflector's VSWR is 1.06, the whole attenuation 0.5 dB, and the bandwidth 4.77 MHz for VSWR less than 1.1. With a laser pulse width of 8.5 ps, beam energy of 4.2 MeV, and bunch charge of 0.64 nC, the bunch lengths for different RF input power into the deflector were measured, and an averaged rms bunch length of 5.25 ps was obtained. A YAG crystal is used as a screen downstream of the deflector, with the calibrated value of 1 pix = 136 μm. 相似文献
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X射线自由电子激光器(FEL)由于其超高亮度、超短脉冲等特点,在世界范围内得到广泛应用。基于尾流场理论,我们计算了上海X射线自由电子激光器(SXFEL)中从直线加速器出口到波荡器末端,束流在245 m不锈钢传输线和波荡器中的阻抗壁尾场。通过对两种不同的阻抗壁尾场的叠加,发现将导致束流纵向相空间的畸变。在SXFEL上进行束流物理的实验,并得到与理论预测非常吻合的实验结果。结合之前对主要直线加速器部分的详细模拟和实验研究,为后续FEL整体束流优化提供了参考。 相似文献
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上海软X射线自由电子激光用户装置(SXFEL)是我国首台可以运行在水窗波段的自由电子激光装置,未来可以为5个实验线站供光,其主要运行模式为自放大自发辐射模式以及外种子模式。本文就SXFEL的外种子模式进行了从头到尾的模拟研究,主要包括EEHG-HGHG混合级联与单级EEHG两种方案。模拟结果表明,虽然EEHG-HGHG混合级联模式较为复杂,但能够产生更高功率的高次谐波辐射。除此之外,我们还研究了各种三维效应对EEHG的影响。模拟和分析结果表明,通过上述两种方案,采用紫外波段的种子激光,用户可以得到全相干、窄带宽、短脉冲的水窗波段自由电子激光。 相似文献
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Burgers equation is reduced into a first-order ordinary differential equation by using travelling wave transformation and it has typical bifurcation characteristics.We can obtain many exact solutions of the Burgers equation,discuss its transcritical bifurcation and control dynamical behaviours by extending the stable region.The transcritical bifurcation exists in the (2 + 1)-dimensional Burgers equation. 相似文献
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