High Power Input Coupler Prototype for Shanghai Hard X-ray Free Electron Laser Device

Hard X-ray free electron laser device

Shanghai hard X-ray free electron laser (shine) is a major national science and technology infrastructure project with the largest investment and the longest construction cycle in China so far. The project task is to build a superconducting linac with an energy of 8gev, three undulator lines, three beam lines and the first batch of 10 experimental stations.

The total length of the hard X-ray free electron laser device is about 3.1km. The project task is to build a superconducting linac with an energy of 8gev, three undulator lines, three beam lines and the first batch of 10 experimental stations. The construction contents of the device include: injector, main accelerator, Fel amplifier (undulator line), light speed line and experimental station, as well as public subsystems including beam diagnosis, control, laser, synchronization, data acquisition and processing, as well as supporting systems and facilities such as low temperature and public facilities.

The construction site of hard X-ray free electron laser device is located in Zhangjiang Science City, with a total investment of nearly 10 billion. It is a core innovation project for Shanghai to build a science and innovation center with global influence and Zhangjiang comprehensive national science center. After completion, the device will become one of the most efficient and advanced free electron laser user devices in the world, provide cutting-edge research means such as high-resolution imaging, ultrafast process exploration and advanced structure analysis for physics, chemistry, life science, material science and energy science, and form a unique and interdisciplinary advanced scientific research platform.

High power input coupler prototype

After completion, it will become one of the most efficient and advanced free electron laser user devices in the world, and can provide cutting-edge research means such as high-resolution imaging, ultrafast process exploration and advanced structure analysis for multiple disciplines. Among them, the 1.3GHz high power input coupler is one of the key components in the cryogenic acceleration module of superconducting linac. It continuously feeds microwave power into the superconducting cavity and provides energy to the beam. The performance of the coupler determines whether the linac can run stably and reliably for a long time.

Entrusted by Shanghai Institute of advanced research, Aerospace Academy (formerly Institute of electronics, Chinese Academy of Sciences) started the domestic independent research and development of 1.3GHz coupler in September 2018. Relying on the relevant process technology of microwave electric vacuum devices, the project team organized technical breakthrough according to the technical indicators and process requirements of the coupler, successively broke through a number of key processes, and comprehensively mastered the process flow of coupler development.

Clean assembly of coupler prototype

At the same time, the project team completed the construction of the supporting level 10 clean room according to the cleanliness requirements of the coupler, and built a 1.3GHz coupler high-power test aging system platform according to the testing aging requirements of the coupler.

In October 2019, the prototype of 1.3GHz high-power input coupler completed the high-power test and aging of pulse 28kw, continuous wave traveling wave 14kw (6h) and continuous wave standing wave 7KW (12h). This batch of coupler prototypes will be installed and debugged in the low-temperature module of the accelerator in the future, and further systematic verification tests will be carried out. Next, COSPAR will continue to complete the delivery of the second batch of coupler prototypes.