Design of Control System for Electron-Beam Diagnostic Equipment Based on Electrical Magnet

An accelerator-based facility, such as an FEL injector, has stringent requirements on the quality of electron beam, and the electron beam is directly determined by beam injector, which is generally a source to provide driven beams with the energy of several MeVs. Since such space-charge dominated relativistic beams are sensitive and easy to be deteriorated during transportation, it is necessary to carry out online monitoring of beam quality under commissioning, so as to achieve accurate measurement of beam parameters such as beam spot size, beam emittance and beam energy spread, and beam current. The whole measuring facility is composed of magnetic components such as analysis magnet and quadrupole magnet. It is necessary to control and monitor the magnet current, and then display the data uniformly to the operating interface and feed back to the user through different control and measuring devices in the system. This paper introduces the basic principle of beam measuring device and the layout design of measuring system. Based on EPICS system and LabVIEW software, a distributed three-layer architecture control and measuring system is developed, which can realize feedback control, remote monitoring and signal acquisition. The whole system is stable and reliable in operation, convenient in use, high in beam parameter accuracy and accurate in calculation, which improves the efficiency of online monitoring.