共查询到20条相似文献,搜索用时 125 毫秒
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合肥先进光源(HALF)是我国规划建设的软X射线与VUV衍射极限储存环光源(DLSR)。如何有效地实现衍射极限束流发射度,是DLSR物理设计中的核心问题之一。基于束流发射度演化方程,针对HALF预研项目的储存环物理设计方案,计算了束内散射(IBS)效应带来的发射度增长,研究了DLSR中关键参数选择对IBS造成的发射度增长的影响。研究表明,在中低能DLSR物理设计中需要综合考虑储存环的周长、同步辐射阻尼时间等关键参数,以更好地抑制束流发射度的增长。在此研究基础上,通过综合考虑用户需求与储存环物理要求,提出了HALF当前工程项目的储存环物理设计方案。进一步综合应用束团拉伸、全耦合等措施后,更高效地抑制了HALF储存环内IBS造成的束流发射度增长。 相似文献
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衍射极限储存环(DLSR)作为第四代同步辐射光源,正得到世界各国的大力发展和建设。如何在尽量减小对存储束流扰动情况下,高效率地将束流注入到储存环中,是衍射极限储存环设计与运行中的重要课题之一。传统的局部凸轨注入法有着很长的历史,应用广泛且技术成熟,但是传统凸轨注入法会对存储束流造成扰动,且衍射极限储存环的动力学孔径较小,这给传统凸轨注入法的应用带来了困难。为了解决这些问题,改进了一些传统的离轴注入法,提出并发展了一些在轴的注入方法。合肥先进光源(HALF)是规划建设中的衍射极限储存环光源,基于HALF储存环的物理设计方案,设计并应用了几种离轴或在轴的注入方案,通过粒子跟踪和模拟的方法验证了它们的可行性并研究了注入效率等物理问题,并对模拟结果进行了讨论和总结。 相似文献
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In this paper, the beam lifetime measurement and its theoretical analysis are presented using measured vacuum pressure and applied radio frequency (RF) cavity voltage in Indus-2 electron storage ring at 2 GeV beam energy. Experimental studies of the effect of RF cavity voltage and bunched beam filling pattern on beam lifetime are also presented. An equation of stable beam current decay is evolved and this equation closely follows the observed beam current decay pattern. It shows that the beam is stable and the beam current decay is due to the beam–residual gas interaction (vacuum lifetime) and electron–electron interaction within a bunch (Touschek lifetime). The estimated vacuum, Touschek and total beam lifetimes from analytical formulations are also compared with the measured beam lifetime. 相似文献
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Hefei Light Source (HLS) is being upgraded to HLS Ⅱ. Its emittance will be much lower than before, therefore the Touschek scattering will increase significantly and become the dominant factor of beam loss. So it is necessary to build a new beam loss monitoring (BLM) system that, in contrast to the old one, is able to obtain the quantity and position information of lost electrons. This information is useful in the commissioning, troubleshooting, and beam lifetime studying for HLS Ⅱ. This paper analyzes the distribution features of different kinds of lost electrons, introduces the operation parameters of the new machine and discusses how to choose proper monitoring positions. Based on these comprehensive analyses, a new BLM system for HLS Ⅱ is proposed. 相似文献
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A passive higher harmonic cavity (HHC) will be used in the Hefei Light Source II Project (HLS-Ⅱ) to lengthen the bunch and consequently increase the beam lifetime dominated by Touschek scattering. The effects of constant voltage and constant detuning have been calculated and compared over the operating current from 0.4 to 0.2 A on the bunch lengthening for the passive normal conducting harmonic cavity system in HLS-Ⅱ. The results show that the bunch shape has less change and the lifetime improvement factors are not less than 2.7 over the beam currents for the constant voltage case. The constant voltage operating scheme may be applied to our machine. 相似文献
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Higher harmonic cavity used in the third generation synchrotron light source increases the Touschek lifetime. The higher harmonic cavity of Shanghai Synchrotron Radiation Facility (SSRF) is a 1.5GHz passive superconducting cavity. Its higher order modes (HOM) are extracted by a ferrite HOM damper out of the cryostat. Multi-cell cavity is chosen concerning the voltage. The harmonic cavity dynamics, beam dynamics with passive harmonic cavity and the design of single cell cavity are included in this paper. 相似文献
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Higher harmonic cavity used in the third generation synchrotron light source increases the Touschek lifetime.The higher harmonic cavity of Shanghai Synchrotron Radiation Facility(SSRF)is a 1.5 GHz passive superconducting cavity.Its higher order modes(HOM)are extracted by a ferrite HOM damper out of the cryostat.Multi-cell cavity is chosen concerning the voltage.The harmonic cavity dynamics,beam dynamics with passive harmonic cavity and the design of single cell cavity are included in this paper. 相似文献
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O. V. Anchugov V. E. Blinov A. V. Bogomyagkov A. N. Zhuravlev S. E. Karnaev G. V. Karpov V. A. Kiselev G. Ya. Kurkin E. B. Levichev O. I. Meshkov S. I. Mishnev N. Yu. Muchnoi S. A. Nikitin I. B. Nikolaev V. V. Petrov P. A. Piminov E. A. Simonov S. V. Sinyatkin A. N. Skrinsky V. V. Smaluk Yu. A. Tikhonov G. M. Tumaikin A. G. Shamov D. N. Shatilov D. A. Shvedov E. I. Shubin 《Journal of Experimental and Theoretical Physics》2009,109(4):590-601
The VEPP-4M accelerator facility with a universal KEDR detector is designed to conduct experiments with colliding electron-positron beams. High-energy physics, nuclear physics, and studies using synchrotron radiation are the main directions of research with this facility. In addition, experiments on poorly explored issues in the physics of beams in the electron-positron storage ring and methodological studies to prepare an experiment aimed at testing corollaries of the CPT theorem for an electron and a positron are regularly conducted at the VEPP-4 facility. A number of works performed in recent years are described: studies to increase the accuracy of comparing the electron and positron spin precession frequencies by the resonant depolarization method; measurements of the count rate of Touschek electrons as a function of the beam energy in a wide range; comparison of the methods for measuring the beam energy spread; a study of the electron beam dynamics when a nonlinear betatron resonance is crossed. 相似文献
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《中国物理C(英文版)》2015,(12)
In an electron storage ring,the bunch length can be increased or decreased by using harmonic cavities.Taking the High Energy Photon Source as an example,we test the bunch length manipulation with harmonic cavities in a diffraction-limited storage ring(DLSR).The most important collective effects in a DLSR,intra-beam scattering and Touschek effects,are evaluated for different bunch-length patterns.Our study shows that it is feasible to produce long and short bunches simultaneously in a DLSR,without causing severe emittance growth and reduction in lifetime. 相似文献
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实验研究了HIRFL-CSRm中电子冷却装置对C6+,Ar15+两种束流寿命的影响。首先,通过对比实验的测量确定电子冷却可以有效提高束流寿命;其次,探究了电子冷却装置中的各项参数(主要是电子束密度分布、流强、能量、绝热展开因子)是如何影响束流寿命的,通过改变电子束参数,测量束流寿命的变化趋势和规律,并且结合电子冷却相关理论对实验结果给予解释,最终通过实验优化和确定最佳的冷却装置参数,使束流在HIRFL-CSRm上获得了较高的寿命,从而提高HIRFL-CSRm束流累积过程中的流强增益。 相似文献
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分析了在储存环中回旋的离子束与残余气体分子、 内靶和冷却电子束相互作用时的损失机制及相应的束流寿命, 针对兰州重离子加速器冷却储存环实验环内靶模式, 计算了50—500 MeV/u 12C6+, 36Ar18+, 132Xe54+和 238U92+等束流在各种损失机制影响下所对应的束流寿命和总的束流寿命。 结果表明: 影响束流寿命的主要因素是与内靶分子(原子)之间的电荷交换及与冷却电子束之间的辐射复合; 对于重离子束 132Xe54+和 238U92+, 与冷却电子束之间的辐射复合是影响其储存寿命的主要因素。The loss mechanism and lifetime of ion beams in collisions with residual gas, internal target and electrons in e cooler in heavy ion cooler storage rings were studied. The partial beam lifetimes resulting from various loss mechanisms and the total beam lifetimes of 50—500 MeV/u12C6+, 36Ar18+, 132Xe54+ and 238U92+ stored in the experimental ring of the Cooler Storage Ring at the Heavy Ion Research Facility in Lanzhou (HIRFL CSR) were calculated. The calculations indicate that the charge exchange process between ion beams and the internal target, as well as the radiative recombination process with the electrons in e cooler restrict the beam lifetime considerably. For heavy ion beams such as 132Xe54+ and 238U92+, the radiative recombination is the dominant loss mechanism 相似文献