Understand the typical applications of ultra-high vacuum and high vacuum technologies(1)
Introduction: The continuous expansion of the application fields of vacuum technology has promoted the integration of different disciplines and the emergence of interdisciplinary subjects. The progress of ultra-high vacuum and high vacuum technologies has driven the development of high-tech industries such as semiconductors, aerospace, and nuclear power, providing a guarantee for the sustainable development of mankind. In recent years, vacuum chambers, pumps, valves, and seals have made new progress driven by the development in fields such as additive manufacturing, nuclear fusion, particle accelerators, and integrated circuits. These advancements have supported important theoretical verifications and major engineering constructions, and spawned new scientific research achievements. This article focuses on introducing several typical applications of vacuum technology and discusses the key technologies involved.

With industrial development and interdisciplinary integration, the application scenarios of vacuum technology have been greatly enriched, and the degree of digitalization and intelligence of related products and scientific instruments has significantly increased. The application conditions in cutting-edge science and emerging fields have become more stringent, and the difficulty and risks of technological breakthroughs have increased significantly. As the four types of basic components of vacuum technology—vacuum chambers, pumps, valves, and seals—their improved manufacturing levels and optimized processes have become important supports for the construction of major scientific installations and the development of high-end equipment, representing the development direction of industrial basic common technologies. To meet the application requirements of process environments, the manufacturing technologies of vacuum chambers and seals have developed rapidly; to adapt to the concept of green and intelligent development, the iteration cycle of vacuum pumps and valves as general technical products has gradually shortened.

The rapid development of technological fields such as aerospace, integrated circuits, particle accelerators, high-speed trains, and nuclear fusion has elevated the performance requirements for vacuum chambers to a new level. Vacuum chambers need to meet application conditions including complex structural shapes, high and low temperature cycles, ultra-high pressure and high vacuum cycles, low leakage, ultra-cleanliness, radiation damage, high-temperature ablation, gravel erosion, and chemical corrosion. China's Tianhe space station has entered a phase of rapid construction, and the long-term stay of astronauts in orbit reflects the rapid development of China's space technology. However, under the existing industrial system, it is difficult to achieve leapfrog development in the service level of the space station, which requires increased investment in scientific and technological forces to achieve disruptive technological results.

The vacuum tube of a particle accelerator can be tens of kilometers long, involving many disciplinary fields, and is a typical representative of ultra-high vacuum and high vacuum technologies. As a research platform for particle theory, accelerator scientific devices have been developed for more than half a century. In addition to being used in basic research, various beamlines of accelerators have been widely applied in fields such as medical treatment and high-resolution dynamic imaging, realizing the integration of scientific research and industry.

Vacuum tube transportation, as a future development direction of transportation, has attracted much attention, with a pipeline diameter of up to 5 meters. The long-term significance of such applications lies in exploring and accumulating technical experience for humans to build permanent bases on extraterrestrial planets.

Ultra-high vacuum technology is widely used, ranging from existing optical sensors, lithography machines, cryostats, electron microscopes, and XPS spectrometers to emerging fields such as cold atom-based portable quantum sensors, MEMS vacuum detection instruments, and vacuum electron beam intelligent additive manufacturing systems. Additive manufacturing can significantly reduce equipment size, weight, and development time, thereby accelerating basic research and technological development. A small ultra-high vacuum chamber for trapping cold atoms using a magneto-optical trap (MOT) was manufactured by a laser powder bed printer, made of aluminum alloy AlSi10Mg. After the system was baked at 120°C for 120 hours, it reached a pressure range lower than 1×10⁻¹⁰ mbar. The device captured fluorescence images of the trapped atomic cloud, containing up to 2×10⁸ rubidium atoms. The vacuum degree of the additively manufactured chamber is better than 5.0×10⁻⁹ mbar, which is consistent with the performance of common magneto-optical trap vacuum chambers, as shown in Figure 1. This indicates the applicability of additive processes in the manufacturing of ultra-high vacuum chambers

Due to the significant competitive advantages of traditional mass manufacturing processes in terms of efficiency and performance, the traditional technical and technological routes will exist for a long time. Additive manufacturing and traditional manufacturing can meet their respective needs and develop in an integrated manner, which can promote the rapid development of related industries. The cooling and heat dissipation components of small and complex vacuum chambers are precision-processed using additive processes, and the flanges manufactured by traditional processes are assembled and welded through connection technologies, so as to achieve the optimal manufacturing process.