A 3 Tesla permanent magnet wiggler [1] has been installed in the ID15 straight section (Figure 182). It replaces the 4 Tesla super conducting wiggler. This prototype consists in two periods of 380 mm. The magnetic field is asymmetric to produce circular polarisation at high energy. The magnetic structure has been optimised for the highest achievable field (3.12 T) at a magnetic gap of 11 mm. The field integral correction versus magnetic gap is particularly delicate due to a high hysteresis of the poles. Note that this is by far the highest magnetic field ever achieved by a permanent wiggler on any synchrotron source.


Fig. 182: 3 Tesla permanent magnet wiggler in the ring tunnel.

Reference
[1] J. Chavanne, P. Van Vaerenbergh, P. Elleaume, Nucl. Inst. Meth. in Phys. Res. A421 352-360 (1999).