Low-energy electron beam sterilizing devices often require a compact size that is suitable for self-shielding, enabling an online disinfection and sterilization procedure on the surface of objects under pipeline conditions. The vertical size of the accelerator is reduced by a compact design, necessitating a small longitudinal size for its scanning magnet. Magnetic testing and numerical simulations are used to define the magnet’s structure and parameters, with measured data further optimizing the design.

Comparing the two scanning magnet models, the calculation results show that the final design has a shorter effective length than the alternative, while achieving a higher and more concentrated magnetic field distribution under the same conditions, thereby meeting the compact design requirements. The two models differ in the placement of the coils and their resulting magnetic field characteristics. The final design was preferred because it not only met the compact size requirement, but also provided superior magnetic field performance in the scanning region.

Furthermore, simulation results have been rigorously compared and validated against the magnetic measurement data. The error is kept within 1% across the actual excitation current range, and the overall error is primarily maintained at 5%. At an excitation current of 1 A, the central magnetic field reaches 85.88 Gs. Additionally, the magnetic field uniformity along the short-side direction of the magnet (y = ±4 mm) and the long-side direction of the magnet (x = ±10 mm) is maintained within a deviation of 1%.

The operational results of the device demonstrate that it meets the scanning requirements for electron beams with energies ranging from 50 to 200 keV, ensuring stable scanning extraction beams and irradiation surface uniformity that satisfy the design specifications