The Beam Position Monitor (BPM) system is one of the most important diagnostic equipment in particle accelerators. It plays a very important role in the debugging, operation, and machine research of the accelerator. The BPM signal processor in the system is the most critical device that determines system performance.
Digital BPM signal processors (DBPM) have wide application prospects in China, including many large science engineering projects based on accelerometers currently under way, industrial accelerators and medical accelerators with strong development momentum. Commercialized digital BPM signal processors have the advantages of mature technology, high reliability, numerous users, and convenient technical exchange, and are the first choice for the above-mentioned various applications. Currently, there is only one foreign company (IT) selling mature products of this kind of signal processor. Almost all new synchrotron radiation light sources (including DLS in the UK, Soleil in France, ALBA in Spain, and TPS in Taiwan) use the company's products, occupying absolute monopoly status. However, the high unit price and huge number of uses have caused the processor to occupy a large amount of project funds. Moreover, the Libera Electron and Brilliance products currently used by Shanghai Light Source have been discontinued and replaced with new products with higher prices, making the operation and maintenance of the light source face higher cost. In addition, the core algorithm is not open, making it impossible for users to optimize algorithms for their specific applications, and cumbersome import and export procedures also make maintenance of the processor more difficult. In addition to the operation and maintenance of several accelerator devices already built in China, the accelerator devices such as Dalian FEL under construction and the Shanghai SXFEL and Northern Light Source to be built soon require a large number of DBPM processors. If all domestic DBPM processors are adopted in such a huge market, it will not only save more than 10 million yuan, but also cultivate a considerable industry.
In this context, the technical team led by researcher Leng Yongbin of the Beam Measurement Group of the Shanghai Institute of Applied Physics, Chinese Academy of Sciences, launched the development of a new digital BPM signal processor with independent intellectual property rights in 2009. During this period, it was successively awarded the 100-member plan of the Chinese Academy of Sciences. Supported by the project, the National Natural Science Foundation of China and the operating funds of Shanghai Light Source.
On the basis of absorbing advanced technologies at home and abroad, and through hard research and innovation, the project team successfully developed a digital BPM signal processor prototype. The prototype has a ring-by-circle position resolution of less than 1 micron, and its performance exceeds that of the IT company's Libera Electron products at the start of the project. It is comparable to the company's latest products, Libera Brilliance and Brilliance Plus products, and can realize user-defined multi-functional data acquisition and processing functions that foreign products do not have. During the prototype development process, the research team not only successfully developed the DBPM principle prototype hardware, but also achieved many innovative results in key signal processing algorithms in the DBPM prototype. Through investigating a large amount of theoretical knowledge, the DFT algorithm was innovatively introduced and the 169-point FFT operation was realized with FPGA. At the same time, technical achievements including multi-channel digital automatic gain adjustment technology and multi-channel on-board self-calibration were achieved. The application of these technologies ensures excellent signal processing capabilities with a ring-by-circle position resolution reaching sub-micron. The project has obtained a total of 1 authorized invention patent and published 9 papers.
This prototype can replace similar foreign products and be used in my country's future large-scale accelerator device construction and transformation projects. It also provides a cost-effective solution for small accelerator applications. After being commercialized, the price of the prototype will be less than half of that of similar foreign products, which will save a lot of construction and maintenance funds.
The successful development of a new DBPM prototype with domestic independent intellectual property rights will break the monopoly position of similar foreign equipment, promote technological openness and exchange in this field, and reduce equipment procurement costs for subsequent accelerator construction and upgrades. It has huge social and economic value. It has laid a solid foundation for the development of the next generation of beam-by-beam BPM signal processors.