Multilayers

THE USE OF A MULTILAYER

  • A multilayer is a succession of screens assembled on the principle of Russian dolls. It starts from the observation that two layers separated by a 1 mm gap is more effective than one 2 mm layer (similar to a double glazing for windows).
     
  • It is used when fields are strong or when looking for a high attenuation. Layer upon layer, the field values decrease dramatically. It is used for:
          - Avoiding saturation phenomena
          - Reaching  extremely low residual field values.
     
  •  It is the ideal solution for a zero gauss chamber.
     
  •  We can reduce the earth’s magnetic field by greater than 10000.
                               Double layer of 1 mm, 4 m high by 1.8 m in diameter.
Heat treatment during 4 hours at 1150 ° C.
Installed in Germany by MMc.

5 layers mumetal
with attenuation> 100 000

Maser for an atomic clock installed on the satellite made from 3 layers supermumetal in a 0.5 mm.
(with 5 layers, attenuation exceeds 1 million).

A DESIGN OF A MULTILAYER

  • It can be made from different alloys: mumetal, pure iron... The choice of material and its thickness depends on the external field and the expected attenuation. For each layer, we work to place the induction level at its maximum permeability.
     
  • Drawing on our knowledge, MMc will advise you on the fixation solution for  the different layers, according to the size of the parts.
     
  •  The number of layers is not limited, but it is rare to have more than 5.