The ID23 straight section is being lengthened from 5 m to 7 m. This work was distributed throughout 2012 and will continue in 2013 with no effect on the operation of the ID23 beamline. The magnets at both ends of the straight section will be replaced by shorter and stronger ones. The two undulators presently in operation will be moved to either end of the straight section, while the centre will be equipped with 3 new single-cell RF accelerating cavities (Figure 149). Generalising this configuration of RF cavities would allow the creation of new beamlines on sectors presently fully occupied by RF cavities.


Fig. 149: Layout of the lengthened ID23 straight section.

In addition to the new magnets and corresponding power supplies installed in the straight section, the modification requires a change of magnet coils and new power supplies that will provide individual control of the quadrupoles over a full cell. These modifications started during the 2011-2012 winter shutdown and will be completed with the installation of the new straight section girders and new magnets during the 2012-2013 winter shutdown. The final step of the operation will see the installation of the three prototypes of HOM-damped RF cavities, scheduled during the summer 2013 shutdown.