The Research Of Control And Measurement Of The High Power Testing Platform Based On High-gradient Accelerating Structures

Shanghai Institute of Applied Physics plans to build an X-ray free-electron laserdevice in its Shanghai campus, in order to provide technical support for theconstruction of an X-ray free-electron laser user device. The body of the device is anelectron linear accelerator with the maximum energy of1.62GeV. The constructionarea is about5500m, so because of the limited construction area and costs, the highgradient accelerating structures is one of the key aspects of them. The design,manufacturing process and high-power conditioning are all essential for thehigh-gradient accelerating structure, among them the high-power conditioningplays an important part in the feedback to the design and manufacturing sectors aswell as the “polished” process of the high-gradient accelerating structure itselfThis paper focuses on the control and measurement of high-power testingplatform, based on the high-gradient accelerating structures. Currently there are a lotof accelerator devices having achieved automatic control, such as the CLIC TestFacility, Spring-8Linac and SNS Accelerator RF Fest Facility. These devices arebasically implemented in hardware to achieve the signal acquisition, and then theyutilize the C, C++, JAVA or other programming languages to analyze the collecteddata. But it has poor performance in real-time on the location of breakdown. Thisarticle attempts to implement the analysis and judgment of the collected datawaveforms in the underlying programmable gate arrays to reach the purpose of thespecific location of the breakdown in real time. This can greatly shorten the time ofdetermining the problem of the hardware malfunction of the accelerator. We can stopthe conditioning process and correct the experience as soon as possible, that increasesthe safety and accuracy of the high-gradient accelerating structure’s testing process.We put the testing platform based on high-gradient accelerating structures intouse during the condition of S-band accelerating tube, and the results conform to theexpectation：auto conditioning, interlock protection, the location of breakdown andother major functions can be properly realized. The entire platform worked steadilyand completed the tasks of the condition of S-band accelerating tube. Especially thespecific location of the breakdown in real time provided a crucial support for the faultdetection and analysis of experiments.