The shielding bellows project for the Hard X-ray Free-Electron Laser facility (beam vacuum shielding bellows for the BC2‑EMIT section) has passed acceptance.
Figure 1: Group photo of the acceptance committee experts and the project research and development team
On July 10, the shielding bellows project for the Hard X-ray Free-Electron Laser facility (beam vacuum shielding bellows for the BC2-EMIT section), undertaken by Zhuoling Precision Equipment (Hefei) Co., Ltd., successfully passed the factory acceptance test. The acceptance meeting brought together 11 authoritative experts from the Shanghai Advanced Research Institute of the Chinese Academy of Sciences and Zhangjiang Laboratory. Through a combination of online and offline meetings, the expert panel conducted rigorous questioning, in-depth discussions, and on-site tests of the project results. After a comprehensive evaluation, the experts unanimously agreed that the project fully meets the design requirements, highly recognized the quality of the work completed, and formally approved the project for factory acceptance.
As a key beam transmission component of the Hard X-ray Free-Electron Laser facility, the BC2-EMIT beam vacuum shielding bellows plays a critical role in maintaining an ultra-high vacuum environment, effectively shielding electromagnetic interference, and ensuring stable beam transmission. The project involves the precision joining of dissimilar materials, featuring a complex manufacturing process. Moreover, the entire workflow requires multi-dimensional and high‑frequency strict inspections, especially for dissimilar-material electron beam welding and post-processing performance requirements such as magnetic permeability and residual magnetism.
The expert panel emphasized that the company achieved scientific coordination across all stages—from requirements analysis and process design to production and testing—through full‑process refined management and control. Key process yields were significantly improved, the project cycle was effectively shortened, and the process management system proved accurate and efficient. In particular, the comprehensive documentation of process information was highlighted as being crucial for the long‑term safe and reliable operation of large-scale facilities.
Figure 2: On-site inspection by the acceptance committee experts
Figures 3/4: Acceptance committee experts observing the test procedure in the cleanroom
Key technical specifications are as follows:
Magnetic permeability: < 1.05
Residual magnetism: < 0.5 Gs
Leak rate: Q ≤ 1 × 10⁻¹² Pa·m³/s
Ultimate vacuum: < 3 × 10⁻⁷ Pa
Residual gas requirement:In the RGA current spectrum, the sum of currents from gases with AMU > 44 (Iamu>44) and the total gas current (Itotal) shall satisfy:
Iamu>44 / Itotal < 1/1000 Ultra-cleanliness requirement:Prior to delivery, in a clean environment better than Class 100 (ISO 5), the component surface shall be purged with clean nitrogen until the particle count (for particles ≥ 0.3 μm) reaches
0. Each flange shall be fitted with a purged, clean nylon flange protector that meets cleanliness standards, and the assembly shall finally be wrapped and sealed in
two layers of LDPE film that meet cleanliness standards
Figure 5: Ultra‑cleanliness inspection of the productFaced with severe technical challenges, the company designated this project as a key research initiative and established a cross‑departmental dedicated R&D team. The team brought together core experts from design and development, special processes, vacuum technology, precision testing, and quality management, with clear division of responsibilities and efficient collaboration. Thanks to this scientific organizational model, standardized manufacturing throughout the entire process, a rigorous quality control system, and comprehensive delivery documentation, the project was successfully completed with high quality and high efficiency.
