View of the PETRA III storage ring (red line) showing the present experimental hall together with the planned additional experimental halls in the North and East. Overall options for additional extensions at the accessible long straight sections are marked with shaded ovals. Two of these are accommodating the damping wiggler (DW) arrays.

The focus of PETRA III is on applications making optimum use of the high beam brilliance, i.e., experiments aiming at nano focusing, ultra-high resolution studies, coherence applications etc.. Other techniques which require photon flux but not necessarily brilliance are being continued very successfully at DORIS III which is operated in parallel to PETRA III sharing its chain of pre-accelerators.

It has been decided to end the SR operation at DORIS III on Oct. 22, 2012. Some very productive beamlines and instruments serve techniques which are not currently implemented at PETRA III. In order to carry on these activities and to provide competitive beamlines and instrumentation for these applications, the experimental facilities at PETRA III will be extended to provide additional beamlines. Overall, there are several options for extension buildings along the circumference of the storage ring, specifically at the long straight sections (Fig. 1) which are well-suited for insertion devices.

This current extension project comprises two new experimental halls on either side of the large new PETRA III hall (North and East) making use of the long straight sections and the adjacent arcs. The northern straight section already accommodates one of the 40 m long damping wiggler arrays producing an extremely hard and powerful X-ray beam which can also be utilized for experiments. The long straight in the east is available for additional insertion devices.