Accelerators 2014

Regarding DESY’s accelerator activities, the year 2014 was characterised by much and decisive progress in our large-scale projects and our research and development programme. The PETRA|III synchrotron radiation facility was shut down as planned for most of the year for the extension project, which comprises the construction of new beamlines in the North and East sections. Removal of the machine and tunnel sections, construction of the new tunnels and experimental halls and re-installation of the accelerator components proceeded very well and within the foreseen schedule. By the end of the year, the work was essentially completed. Re-commissioning of the machine will take place in early 2015, fully in accord with the project plan, and first users in the Max von Laue experimental hall can expect photon beams by the end of the first Suarter of 2015. 9hile getting PETRA|III back into routine operation is the primary goal, investigations of possible performance improve-ments for the future are also continuing. It was found that limita-tions of the achievable (already very small) horizontal emittance are not only caused by the focusing strengths in the regular PETRA|III arcs but also by the beam optics of the pnew eighthq section. First concepts to mitigate these limitations have been worked out, and the potential of PETRA|III for even smaller emit-tances will be further explored in the future. The shutdown of PETRA|III was a good opportunity to perform improvements on the pre-accelerators, which had been on the to-do list for quite a while. In particular, installing an additional new injector gun in the LINAC II pre-accelerator was an important measure to elimi-nate a potentially serious operation reliability risk by providing a backup for the electron beam source. This work, together with other refurbishments, was completed well in time to get the pre-accelerator chain back into operation to deliver beam for the PETRA|III re-commissioning in 2015.