论文标题
高级轻源升级项目的数字低级RF控制系统用于累加器环
Digital Low-Level RF control system for Accumulator Ring at Advanced Light Source Upgrade Project
论文作者
论文摘要
目前，ALS正在对ALSU进行升级，以产生100倍更明亮的软X射线灯。累加环（AR）的LLRF系统由两个相同的LLRF站组成，用于驱动RF放大器。在系统内的架构下，使用非IQ数字下降转换以及模拟上/向上转换，封闭环路振幅和相位稳定性分别为$ <0.1 \％$和$ <0.1 \％$和$ <0.1^\ Circ $。实时互锁系统是用$ <2μ$ s的延迟实现的，以防止弧闪存和意外的RF功率。开发控制接口是为了启用PLC-FPGA-EPICS通信以支持操作，时机，空腔调整和互锁系统。 LLRF系统通过同步相环在两个腔之间横冲直撞，处理桶的对齐，以在AR和存储环之间交换光束。该系统还包括一个优化例程，以表征循环动力学并使用内置网络分析仪功能确定最佳操作点。 31 kHz带宽的空腔仿真器与LLRF系统集成在一起，以验证正在开发的整体系统的性能。
Currently ALS is undergoing an upgrade to ALSU to produce 100 times brighter soft X-ray light. The LLRF system for Accumulator Ring (AR) is composed of two identical LLRF stations, for driving RF amplifiers. The closed loop RF amplitude and phase stability is measured as $< 0.1\%$ and $< 0.1^\circ$ respectively, using the non-IQ digital down conversion together with analog up/down conversion, under a system-on-chip architecture. Realtime interlock system is implemented with $< 2 μ$s latency, for machine protection against arc flash and unexpected RF power. Control interfaces are developed to enable PLC-FPGA-EPICS communication to support operation, timing, cavity tuning, and interlock systems. The LLRF system handles alignment of buckets to swap beams between AR and Storage Ring by synchronous phase loop ramping between the two cavities. The system also includes an optimization routine to characterize the loop dynamics and determine optimal operating point using a built-in network analyzer feature. A cavity emulator of 31 kHz bandwidth is integrated with the LLRF system to validate the performance of the overall system being developed.
