IMP's SSC Coil System Upgrade Project Successfully Passes Acceptance Review
2025-08-06 15:46:48
汤桐生
0
June 9, 2021, Shanghai – The Institute of Modern Physics (IMP), Chinese Academy of Sciences, conducted the final acceptance review for the SSC Coil System Upgrade Project at Shanghai Kering Technology Development Co., Ltd., with all deliverables unanimously approved by the expert panel.
Project Background: Critical Upgrade Requirements
The Large Separated-Sector Cyclotron (SSC) serves as the core component of the Heavy Ion Research Facility in Lanzhou (HIRFL). Its main magnet system comprises four straight-edge sector magnets (52° bending angle, ~500 tons each), each equipped with main coils and shim coils. The system totals 16 coil sets (8 main coils + 8 shim coils).
Operational Challenges:
l SSC coil system exceeded 30 years of service with severe insulation degradation
l Risks of interturn insulation failure or ground arcing could force facility shutdown (coil replacement cycle ≥6 months)
l Original system unable to meet beam quality requirements for advanced heavy-ion physics research
Upgrade Scope: Comprehensive Technical Transformation
The project executed a full-system overhaul:
1、Core Component Replacement:
Upgraded 8 degraded main coils (upper/lower)
Modernized obsolete water-cooling systems and mechanical parts
2、Critical Spares Preparation:
Fabricated 1 additional shim coil set as operational backup
3、Specialized Tooling Development:
Custom-engineered large-scale flipping, hoisting, lifting, transfer, and storage equipment
Breakthrough Innovations: Performance Surpassing Benchmarks
After 2.5 years of collaborative R&D, key metrics exceeded acceptance criteria:
Technical Parameter | Original System | Upgraded System | Improvement |
Conductor Material | Pure Copper | Oxygen-Free Copper (TU1) | ↑ Conductivity & Mechanical Strength |
Insulation Process | Polyimide Tape + Secondary Curing | Vacuum Epoxy Impregnation | ↑ Reliability/Endurance/Water & Radiation Resistance |
Casing & Welding | Swiss Imported Stainless Steel | Domestic SS + Optimized Welding | Permeability <1.01 (no annealing) |
Vacuum Leak Rate | 6.6×10?? – 1×10?? Torr·l/s | 1.52×10??? Torr·l/s | ↓ Leakage by one order of magnitude |
Key Process Achievement:
Sub-1.01 permeability casing achieved through 50+ major experiments, 200+ minor trials, and 6-month process optimization – without high-temperature annealing – relying solely on material selection and welding innovation.
Strategic Impact: Enabling Next-Gen Scientific Facilities
The upgraded SSC coil system:
l Fully complies with particle accelerator industry and national standards
l Delivers significantly enhanced magnet reliability and quality
l Supports integration with front-end superconducting ion sources and back-end CSR systems
l Provides critical infrastructure for precision heavy-ion physics experiments
