Device cylindrical permanent magnet producing a magnetic control field has a distance from its surface

The device comprises a base structure (10) and an assembly (20) concentric magnetic structures (21, 22, 23, 24) in the form of non-contiguous rings disposed on the same side of the base structure (10) defining an active outer surface to produce a controlled magnetic field (B) outside the magnet device in an outer area of ​​interest (3) located at a predetermined distance from the active surface. At least one concentric magnetic structures (21, 22, 23, 24) is divided into components in the form of non-contiguous identical sectors regularly distributed. The base structure (10) and the assembly (20) are magnetized in the same direction (M) so as to create in the outer area of ​​interest (3) the induced magnetic field (B) controlled.