高品质的束流是产生高品质同步辐射光或自由电子激光的关键,电子直线加速器作为同步辐射光源的注入器,其性能表现直接影响到束流品质。为降低噪声(温度变化、机械振动等)的干扰,本文研究和实现了一个通用、鲁棒、高效、可扩展性好的电...高品质的束流是产生高品质同步辐射光或自由电子激光的关键,电子直线加速器作为同步辐射光源的注入器,其性能表现直接影响到束流品质。为降低噪声(温度变化、机械振动等)的干扰,本文研究和实现了一个通用、鲁棒、高效、可扩展性好的电子直线加速器低电平控制系统。目前已经实现了自动频率控制(Automatic Frequency Control,AFC)功能,更多控制功能将会陆续实现。该系统基于MicroTCA,选用实验物理与工业控制系统(Experimental Physics and Industrial Control System,EPICS)架构,采用C/C++开发,利用PID(ProportionIntegral-Differential)算法和最小二乘法,能够采用两种不同的方法进行自动频率控制。在巴西Sirius光源直线加速器实验装置上对该控制系统进行调试和测试,结果表明,两种AFC方法都是有效的,且存在明显差异,未来将进一步优化和完善。展开更多
Modern low-level RF （LLRF） control systems of particle accelerators are designed to achieve extremely precise field amplitude and phase regulation inside the accelerating cavities. The RF field signal is usually con...Modern low-level RF （LLRF） control systems of particle accelerators are designed to achieve extremely precise field amplitude and phase regulation inside the accelerating cavities. The RF field signal is usually converted to an intermediate frequency （IF） before being sampled by ADC. As the down-conversion is an important procedure of digital signal processing in LLRF system, designing a high performance and broad band downconverter compatible with various accelerators is important. In this paper, the design of a downconverter based on MicroTCA and its performance evaluation on different frequency points are presented. The major design objective of this module is a wider operating frequency range and more flexibility in application.展开更多
本文介绍了基于MicroTCA.4标准的新型宽带射频前端的设计。该射频前端可以实现300MHz^6 GHz频率范围内的下变频及50 MHz^6 GHz范围内的矢量调制上变频。同时射频前端具有可调衰减、温度监测、功率检波、IQ校准、板卡管理等功能。通过测...本文介绍了基于MicroTCA.4标准的新型宽带射频前端的设计。该射频前端可以实现300MHz^6 GHz频率范围内的下变频及50 MHz^6 GHz范围内的矢量调制上变频。同时射频前端具有可调衰减、温度监测、功率检波、IQ校准、板卡管理等功能。通过测试,板卡下变频端口间隔离度大于70d B,下变频线性区间大于35 d B,幅度误差小于0.03%,相位误差小于±0.03°;上变频载波泄露小于-45 d Bm,边带抑制大于50 d B。展开更多
文摘高品质的束流是产生高品质同步辐射光或自由电子激光的关键,电子直线加速器作为同步辐射光源的注入器,其性能表现直接影响到束流品质。为降低噪声(温度变化、机械振动等)的干扰,本文研究和实现了一个通用、鲁棒、高效、可扩展性好的电子直线加速器低电平控制系统。目前已经实现了自动频率控制(Automatic Frequency Control,AFC)功能,更多控制功能将会陆续实现。该系统基于MicroTCA,选用实验物理与工业控制系统(Experimental Physics and Industrial Control System,EPICS)架构,采用C/C++开发,利用PID(ProportionIntegral-Differential)算法和最小二乘法,能够采用两种不同的方法进行自动频率控制。在巴西Sirius光源直线加速器实验装置上对该控制系统进行调试和测试,结果表明,两种AFC方法都是有效的,且存在明显差异,未来将进一步优化和完善。
文摘Modern low-level RF （LLRF） control systems of particle accelerators are designed to achieve extremely precise field amplitude and phase regulation inside the accelerating cavities. The RF field signal is usually converted to an intermediate frequency （IF） before being sampled by ADC. As the down-conversion is an important procedure of digital signal processing in LLRF system, designing a high performance and broad band downconverter compatible with various accelerators is important. In this paper, the design of a downconverter based on MicroTCA and its performance evaluation on different frequency points are presented. The major design objective of this module is a wider operating frequency range and more flexibility in application.
文摘本文介绍了基于MicroTCA.4标准的新型宽带射频前端的设计。该射频前端可以实现300MHz^6 GHz频率范围内的下变频及50 MHz^6 GHz范围内的矢量调制上变频。同时射频前端具有可调衰减、温度监测、功率检波、IQ校准、板卡管理等功能。通过测试,板卡下变频端口间隔离度大于70d B,下变频线性区间大于35 d B,幅度误差小于0.03%,相位误差小于±0.03°;上变频载波泄露小于-45 d Bm,边带抑制大于50 d B。
