Before the RF cavities are installed during the summer 2013 shutdown, the space they will eventually occupy will be free for the first six months of the year. During that time, an additional quadrupole will be installed and powered during machine dedicated studies only. The aim is to test the possibility of splitting a long straight section into two halves with a small vertical β of 1.5 m in the middle of each half. This configuration could allow a further reduction of the undulator gaps, possibly down to 4 mm. Although such undulators are not currently available, the tests will provide the opportunity to check the impact on the machine performance of such a significant modification of the optics, in particular on injection efficiency and lifetime.