介绍了数字BPM算法的原理和架构,并基于高能物理研究所自制的数字BPM硬件平台获取了BEPCⅡ束流流强为600 m A条件下的ADC采样数据。然后在MATLAB环境中设计了NCO模块、CIC滤波器、FIR滤波器以及BEPCⅡ束流逐圈位置数据计算模块,并给出...介绍了数字BPM算法的原理和架构,并基于高能物理研究所自制的数字BPM硬件平台获取了BEPCⅡ束流流强为600 m A条件下的ADC采样数据。然后在MATLAB环境中设计了NCO模块、CIC滤波器、FIR滤波器以及BEPCⅡ束流逐圈位置数据计算模块,并给出了各模块的具体设计参数。最后通过实际ADC数据对各算法模块进行检验,给出了各模块处理后的频域分析结果,并得到了实际束流下水平方向和垂直方向上的逐圈位置分辨率分别为4. 55μm和4. 28μm,为FPGA在线算法的实现与优化提供了可靠的理论依据。展开更多
The coherent synchrotron radiation （CSR） effect emittance dilution in high-brightness light sources and linear in a bending path plays an important role in transverse colliders, where the electron beams are of short...The coherent synchrotron radiation （CSR） effect emittance dilution in high-brightness light sources and linear in a bending path plays an important role in transverse colliders, where the electron beams are of short bunch length and high peak current. Suppression of the emittance growth induced by CSR is critical to preserve the beam quality and help improve the machine performance. It has been shown that the CSR effect in a double-bend achromat （DBA） can be analyzed with the two-dimensional point-kick analysis method. In this paper, this method is applied to analyze the CSR effect in a triple-bend achromat （TBA） with symmetric layout, which is commonly used in the optics designs of energy recovery linacs （ERLs）. A condition of cancelling the CSR linear effect in such a TBA is obtained, and is verified through numerical simulations. It is demonstrated that emittance preservation can be achieved with this condition, and to a large extent, has a high tolerance to the fluctuation of the initial transverse phase space distribution of the beam.展开更多
The emittance growth induced by Coherent Synchrotron Radiation （CSR） is an important issue when electron bunches with short bunch length and high peak current are transported in a bending magnet. In this paper, a si...The emittance growth induced by Coherent Synchrotron Radiation （CSR） is an important issue when electron bunches with short bunch length and high peak current are transported in a bending magnet. In this paper, a single kick method is introduced that could give the same result as the R-matrix method, but is much easier to use. Then, with this method, an optics design technique is introduced that could minimize the emittance dilution within a single achromatic cell.展开更多
文摘介绍了数字BPM算法的原理和架构,并基于高能物理研究所自制的数字BPM硬件平台获取了BEPCⅡ束流流强为600 m A条件下的ADC采样数据。然后在MATLAB环境中设计了NCO模块、CIC滤波器、FIR滤波器以及BEPCⅡ束流逐圈位置数据计算模块,并给出了各模块的具体设计参数。最后通过实际ADC数据对各算法模块进行检验,给出了各模块处理后的频域分析结果,并得到了实际束流下水平方向和垂直方向上的逐圈位置分辨率分别为4. 55μm和4. 28μm,为FPGA在线算法的实现与优化提供了可靠的理论依据。
基金Supported by National Natural Science Foundation of China(11475202,11405187)Youth Innovation Promotion Association of Chinese Academy of Sciences(2015009)
文摘The coherent synchrotron radiation （CSR） effect emittance dilution in high-brightness light sources and linear in a bending path plays an important role in transverse colliders, where the electron beams are of short bunch length and high peak current. Suppression of the emittance growth induced by CSR is critical to preserve the beam quality and help improve the machine performance. It has been shown that the CSR effect in a double-bend achromat （DBA） can be analyzed with the two-dimensional point-kick analysis method. In this paper, this method is applied to analyze the CSR effect in a triple-bend achromat （TBA） with symmetric layout, which is commonly used in the optics designs of energy recovery linacs （ERLs）. A condition of cancelling the CSR linear effect in such a TBA is obtained, and is verified through numerical simulations. It is demonstrated that emittance preservation can be achieved with this condition, and to a large extent, has a high tolerance to the fluctuation of the initial transverse phase space distribution of the beam.
文摘The emittance growth induced by Coherent Synchrotron Radiation （CSR） is an important issue when electron bunches with short bunch length and high peak current are transported in a bending magnet. In this paper, a single kick method is introduced that could give the same result as the R-matrix method, but is much easier to use. Then, with this method, an optics design technique is introduced that could minimize the emittance dilution within a single achromatic cell.
