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电子直线加速器束流动力学的三维理论和计算 总被引:2,自引:0,他引:2
本文提出了电子直线加速器束流动力学计算的三维理论。将注入的脉冲束流划分为等电荷的环,追踪这些环在三维几何空间的运动,并在六维相空间内讨论束流的性能,给出束流在(r,p_r),(rθ,p_θ),(z,p_Z)三个相平面上的图象以及均方根发射度的数值。本文还介绍了应用三维理论的实例计算结果,并对影响径向发射度的因素作了讨论。 相似文献
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BEPCⅡ直线加速器采用改变四极磁铁励磁电流,测量获取的束流横截面荧光图像得到束流包络,进而通过对束流包络和励磁电流的拟合计算得到束流发射度和Twiss参数.在BEPCⅡ直线加速器的改进过程中,发现并解决了影响发射度测量结果准确性的多个问题,改进了束流横截面测量方法和发射度计算方法,提高了测量结果的准确性.根据BEPCⅡ直线加速器的具体情况,还编写了束流截面测量程序和发射度计算程序,提高了发射度的测量和计算速度,方便了发射度测量实验的使用. 相似文献
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研究了束流传输理论沿用的束流相空间与实测束流发射度椭圆之间的对应关系,推导了束流相空间参数与束流椭圆对应关系的表达式,为束流传输理论与束流测量实验之间的相互验证提供了直接依据。 相似文献
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能散度是反映束流品质的重要参数,采用传统测量方法测量时打到靶上的束流不能得到利用,测得的数据也是多个宏脉冲的平均值,利用该方法的测量结果进行束流调节时,要等待荧光靶从束流轨道中反复插入和提出,调节时间很长。基于单个四条带束流位置检测器,结合发射度测量的方法,实现了非拦截式能散度测量方法。该方法能在不加入额外设备的情况下对每个束流宏脉冲的能散度进行测量,测量结果与传统的拦截式测量方法结果相吻合。进行了误差分析,指出为了减小测量系统误差,需要尽可能使束流通过束流位置检测器中心。 相似文献
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利用束流截止板热量计原理,测量了诊断中性束(DNB)注入托卡马克的束流功率及束流剖面分布。基于热量截止板上正交分布的13只K型热电偶探针测量出DNB引出束流,在加速极电源49 kV,6 A,100 ms的脉冲放电时,采样铜靶上的最高温升为14 ℃,从而计算出注入束流功率达到160 kW并得到束剖面分布。同时通过对热量截止板冷却循环水温升测量值在时间上的积分数值计算,也获得了注入束流总功率,为130 kW。分析了两种测量结果存在差异的原因,实验结果表明惯性束截止板热量计方法是测量粒子束流功率及剖面分布的有效手段。 相似文献
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3.5 MeV 注入器是“神龙一号”直线感应加速器的束源,在注入器束流调试中,首先通过数值模拟方法,初步确定束流过聚焦和聚焦不足两种极端情况下引出线圈输运磁场峰值的变化范围;然后以注入器出口束流波形为参考,通过实验调试找到了这两种情况下引出线圈输运磁场峰值的实际配置;再通过测量束流的剖面或发射度,在这两种配置中选定一个折中的引出线圈磁场配置,并最终确定了注入器输运磁场的总体配置。经过调试完成后的注入器束流为3.6 MeV,流强为2.8 kA,归一化边发射度为1 040 mm·mrad,达到了预期的指标。 相似文献
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An ion beam extracted from an ECRIS suffers from the inhomogeneous distribution of cold electrons within the minimum B configuration,necessary to confine the plasma.Especially for higher ion currents,the space charge force is not negligible any more,and because of the nonlinear force,emittance growth will occur. Measurements of the profile and the emittance of the beam directly behind the source show the complicated correlation between extraction voltage and plasma density.The emittance has been measured with a pepper pot device to account for the inhomogeneous azimuthal distribution of the beam.These results indicate that further information about the profile is required.To visualize the beam profile a tantalum foil with a thickness of 20μm has been used for an electrical beam power between 10 and 50W.Looking on the back side of the foil with a CCD camera it is possible to record the profile in real time.As a more sensitive diagnostic tool viewing targets made from BaF has been used. Three dimensional computer simulations have been used to identify the reason for the structures,observed in measurements. 相似文献
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Beam experiments with a non-intercepting beam induced f luorescence profile monitor for the ADS LINAC 下载免费PDF全文
XIE Hong-Ming WU Jun-Xia ZHANG Yong ZHU Guang-Yu XIA Jia-Wen YE Min-You 《中国物理C(英文版)》2015,39(11):117004-117004
An accelerator-driven subcritical system(ADS) project was launched in China in 2011, aiming to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power. The driver linac is defined to be a 10 m A current of high energy protons at 1.5 Ge V in continuous wave operation mode. To meet the extremely high power and intense beam accelerator requirements, non-interceptive monitors for the beam transverse profile are required for this proton linac. Taking advantage of the residual gas as active material, the Beam Induced Fluorescence(BIF) monitor exploits gas-excited fluorescence in the visible spectrum region for transverse profile measurements. The advantages of this non-intercepting method are that nothing is installed in the vacuum pipe,component design is compact and there is no need for expensive signal processing electronics. Beam experiments have been performed under constant beam conditions. The helium spectrum has been verified with different optical filters, showing that a proper optical band-pass filter covering 400–500 nm is necessary for fluorescence experiments with helium. By changing gas pressure, it is shown that gas pressure is proportional to the signal amplitude but has no influence on detected profile width. Finally, a comparison experiment between the BIF monitor and a wire scanner shows that the detected profile width results of both methods agree well. 相似文献
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Yuanshuai QIN Zhijun WANG Chi FENG Shuhui LIU Weiping DOU Weilong CHEN Wangsheng WANG Hongming XIE Yuan HE 《原子核物理评论》2021,38(1):30-37
在C-ADS直线加速器样机中,为了描述束流相空间分布,需要精确测量束流在RFQ出口处的参数。束流横向信息已通过发射度重构测量获得,束流光学也得到了验证。采用了一种用BPM的SUM信号测量束流纵向参数的方法。在实验中,调节两台聚束器的聚束腔压并记录其下游BPM上的SUM信号。通过粒子群算法和TraceWin模拟相结合的方法,得到了考虑空间电荷效应的测量结果。测得的发射度与Toutatis中的模拟值相近。 相似文献
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Fritzler S Lefebvre E Malka V Burgy F Dangor AE Krushelnick K Mangles SP Najmudin Z Rousseau JP Walton B 《Physical review letters》2004,92(16):165006
The transverse emittance of a relativistic electron beam generated by the interaction of a high-intensity laser with an underdense plasma has been measured with the "pepper-pot" method. For parameters pertaining to the forced laser wakefield regime, we have measured an emittance as low as (2.7+/-0.9) pi mm mrad for (55+/-2) MeV electrons. These measurements are consistent with 3D particle-in-cell simulations of the experiment, which additionally show the existence of a relatively large halo around the beam core. 相似文献
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本文介绍了新近在中国工程物理研究院建成的一台直线感应加速器。这台加速器由六个250kV的加速组元构成。其中四个用于构成电子源,另外两个用作后加速。输出电子束能量为1.5MeV,束流2—3kA,束脉冲宽度90ns,束的非归—化均方根发射度70mrad-cm。 相似文献
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切伦科夫辐射“双成像法”测量电子束发射度 总被引:5,自引:0,他引:5
利用切伦科夫辐射,OTR或荧光靶等光学诊断方法进行发射度测量,国内外绝大部分实验是用CCD相机观测电子束打靶产生的光斑,变化四极透镜的磁场梯度,应用“三梯度法”计算出发射度.文中提出了一种新的“双成像法”测量方法,使切伦科夫辐射光通过一长焦距的消色差薄透镜,分别在焦平面和像平面获取图像.通过图像处理,前者可分析出电子束散角分布,后者可分析出电子束径向分布,从而直接得到均方根发射度.该方法对束流相空间和电荷密度分布无需假设,无需借助“三梯度法”,较其他常规测量方法具有实验装置更简便、测量精度更高和适用性更广等优点.文中给出了该测量方法对北京大学DC?SC光阴极注入器的发射度测量进行计算机模拟实验的结果和分析. 相似文献