The Institute of Electrical Engineering of Chinese Academy of Sciences, Institute of High Energy Physics and China Academy of Launch Vehicle Technology have successfully developed the most critical permanent magnet system of Alpha Magnetic Spectrometer, including the permanent magnet made of high-performance NdFeB material and the main structure supporting the whole magnetic spectrometer. The unique magic ring design meets the strict requirements of space experiments on magnetic leakage and magnetic dipole moment.

The total weight of the permanent magnet is about 2t, the sensitivity is 0.6m2 sr, the magnetic deflection capacity BL2 is 0.135t m2, and it will not demagnetize below 40℃. The main structure adopts a double-layer thin shell system, which can bear the strong magnetic force and torque of permanent magnets and the huge load when taking off and landing. The permanent magnet system has passed the rigorous space environment simulation test, met the requirements of alpha magnetic spectrometer, and reached the strict safety and reliability standards of NASA.

Alpha Magnetic Spectrometer 2 tries to use superconducting magnets instead of permanent magnets. Although this method can generate a stronger magnetic field, the superconducting magnet needs liquid helium to cool, and liquid helium cannot be replenished in space, so the life of the magnetic spectrometer is only 3 years. However, the service life of magnetic spectrometer using permanent magnet is as long as 18 to 20 years, so experts decided to use permanent magnet.