The new septum magnets

In an earlier paper we reported on a new septum magnet design with a magnetic flux filter [1]. Now the first septum magnet is in operation as an injection septum magnet for the MAX I storage ring. We describe the actual mechanical construction and the field measurements of the new magnets. The fine structure of the septum nose needed several trials in the construction until we found the final solution. The measured residual stray fields in the ring tube are even smaller than was expected from the model calculations.