The first experimental set-up to profit from the LEBIT beam-line will be a 9.4 T Penning trap system for high-precision mass measurements.
One of the prerequisites for this experiment is a highly homogeneous magnetic field in the interior of the trap. The field in the region of the trap produced by the magnet may be considered homogenous (spec: DB/B<1 ppm, |z|<2 cm); care has to be taken to eliminate field distortions introduced by the diamagnetic material used for the trap electrodes and their mounting. Starting from the current ISOLTRAP design the electrode layout was modified in order to minimize induced field inhomogeneities.
The figure to the left shows the trap with the modifications applied.
The figure to the right shows a comparison of the axial field inhomogeneities produced by the
trap in the original ISOLTRAP design and
by the modified version.