Design of machine protection system for CAFe facility

Background In an accelerator-driven sub-critical system(ADS),a strong proton beam from a high-power proton accelerator irradiates a spallation target to produce very intense neutrons for driving a reactor.Currently,the China ADS front-end demo linac(CAFe)facility is being built to provide strong beam with the beam intensity of several mAs.Purpose This paper reports the machine protection system(MPS)of the CAFe facility,which prevents or minimizes the beam-induced damages or the damages from other sources to the machines in the accelerator.Method The MPS of CAFe facility works under the framework of experimental physics and industrial control system(EPICS).The developed machine protection system includes fast protection function and slow interlock function,where the fast function is performed by FPGA controller and the slow function is performed by PLC controller.Results Based on the reports on the status of all relevant subsystems,MPS will either perform an emergency shutdown of the beam or machine or will permit normal operation.When an emergency shutdown of the beam is needed,MPS switches off the ion source or switches on the chopper.In addition to its protective role,MPS will also trace the origin of an emergency shutdown.Conclusions The developed MPS has played an important role during the commissioning and successful operation of the CAFe facility at the end of 2019.

A new deploymentmethod of the archiver application with Kubernetes for the CAFe facility

Background The control system of the China ADS front-end demo linac(CAFe)facility has been built based on a software tool entitled the“Experimental Physics and Industrial Control System”(EPICS).In the EPICS system,the online acquisitions,storage and historical data queries are completed in the Archiver Appliance system.For the construction,upgrading,operation and maintenance of the CAFe facility,it is necessary to use a convenient and reliable archiver system.To reconstruct the CAFe accelerator from a research facility to an experimental facility,some functions of the control system have been reformed to improve the reliability of the facility operation.Purpose This paper presents a new deployment of the Archiver Appliance.The Archiver engine is deployed in a Kubernetes(K8S)cluster as a container.The horizontal pod scaling(HPA)strategy was formulated to implement the automatic expansion and contraction of the application.Methods The Docker containers of the Archiver Appliance have been built and run in the pods of the K8S clusters,which can implement automatic expansion and contraction of the application.The combination scheme with the Prometheus,Dashboard and Grafana schemes has been used to jointly build a monitoring system for the cluster and the pods inside the cluster.Results Currently,the Archiver Appliance system with K8S clusters is under commissioning at the CAFe facility.This deployment method fulfills the requirements of the CAFe experimental facility for portability,high availability and disaster tolerance of archive server software.