Fig. 1. 3D structure of the SRing electron cooler

Fig. 2. Cooling section design of the SRing electron cooler

Fig. 3. Key mechanical parameters of one solenoid coil and its adjusting system

Fig. 4. Structure of magnetic field measurement platform

Fig. 5. Magnetic field measurement results and stabilities

Fig. 6. Vector analysis of magnetic field

Fig. 7. Angle relative error between the coil magnetic field axis and the geometric symmetrical axis due to Hall plates installation error

Fig. 8. Photo of coil on the magnetic field measurement

Fig. 9. Background magnetic field measurement result

Fig. 10. Magnetic field measurement of one coil with the current of 125 A (front side)

Fig. 11. Magnetic field measurement of one coil with the current of 125 A (opposite side)

Fig. 12. Measurement results of magnetic field axis angle and direction with different operation current