The SESAME microtron, which was previously in use at BESSY I but has been refurbished and upgraded, accelerated a beam to the full energy of 22.5 MeV on 14 July 2009 while temporally installed in the SESAME hall. It was later installed in its final position, where at 1.13 a.m. on Monday 28 November 2011 an electron beam with the full energy was successfully extracted. It is the first part of the SESAME accelerator complex to have become fully operational.
The microtron provides the initial acceleration and injects electrons into the booster, which in turn injects electrons (at an energy of 800 MeV in the case of SESAME) into the storage ring (at SESAME, this is a new 2.5 GeV storage ring).