The 1.5 GeV harmonic double-sided microtron at Mainz University
The 1.5 GeV harmonic double-sided microtron at Mainz University
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美因茨大学的 1.5 GeV 谐波双面微电子管
DOI：
10.1016/j.nima.2008.05.018
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发表时间：
2008
影响因子：
1.4
通讯作者：
A. Thomas
中科院分区：
文献类型：
--
作者：
K. Kaiser;K. Aulenbacher;O. Chubarov;M. Dehn;H. Euteneuer;F. Hagenbuck;R. Herr;A. Jankowiak;P. Jennewein;H. Kreidel;U. Ludwig;M. Negrazus;S. Ratschow;S. Schumann;M. Seidl;G. Stephan;A. Thomas
美因茨大学核物理研究所建造了一台谐波双面微加速器(HDSM)，将核物理和粒子物理实验的实验能力扩展到更高的激发能。这一新的微加速器变种将已建立的三级赛道微加速器(RTM)级联Mami B的0.855GeV连续波(CW)电子束加速到1.5GeV。它由两个普通的导电直线加速器(直线加速器)组成，电子通过这两个直线加速器被两端一对90°弯曲的磁铁引导多达43次。由于束流动力学的原因，直线加速器的工作频率分别为4.90 GHz和2.45 GHz。扩展的设施被称为Mami C。由于分段形弯曲磁铁的入口处和出口处的45°极表面旋转(图1)而产生的相对较强的垂直散焦通过在磁铁中朝着更高轨道的适当场衰减来补偿所有的再循环。因此，为了保持相干加速，电子的能量增益必须随着圈数的增加而减小。这是由于电子在加速过程中沿着射频波束向下适当的位相滑移而发生的。介绍了双面微加速器(DSM)的工作原理、束流动力学概念及其主要部件的设计和研制。最后，讨论了2006年12月启动后的第一束测量结果。
At the Institut für Kernphysik of Mainz University a harmonic double-sided microtron (HDSM) has been built to extend the experimental capabilities for nuclear and particle physics experiments to higher excitation energies. This novel microtron variant accelerates the 0.855GeV continuous wave (cw) electron beam of the established three-staged race track microtron (RTM) cascade MAMI B up to 1.5GeV. It consists of two normal conducting linear accelerators (linacs) through which the electrons are guided up to 43 times by a pair of 90°-bending magnets at each end. For beam dynamical reasons the linacs operate at the harmonic frequencies of 4.90 and 2.45GHz. The extended facility is called MAMI C. The relatively strong vertical defocussing due to the 45°-pole face rotations (Fig. 1) at both the entrance and exit of the segment-shaped bending magnets is compensated for all recirculations by a suitable field decay in the magnets towards higher orbits. As a consequence, the energy gain of the electrons has to decrease with increasing turn number to maintain coherent acceleration. This occurs by an appropriate phase slip of the electron bunches downwards the rf-waves during the acceleration process. In this paper the functional principle and the beam dynamical concept of the double-sided microtron (DSM) as well as the design and development of its main components are described. Finally, the results of first beam measurements taken after starting up in December 2006 are discussed.