Status JRA-SRF List of submitted deliverable reports Report on continuing activities –WP 2, WP 4 Status of remaining deliverables Highlights Approaching the end of JRA-SRF –Annual meeting 2008 –Final reports

Status WP2.2 Improved component design First cavity prototype with bellows in the middle of the He tank finished and successful tested (tuner WP 8.1) Design of an improved end group finished Construction contract placed to ZANON for two new end groups (end of July) Mechanical test of new end group starts end of October

5 mm NbTi end dish. Stiffness is about 28 kN/mm for each end dish. 7 mm NbTi end dish. Stiffness is about 38 kN/mm Curved NbTi end dish. Stiffness is about 69 kN/mm Stresses (MPa) are calculated for 2 bar pressure difference.

WP 4 Vacuum arc coating Detailed studies on samples to improve the adhesion –Treatment with 15% citric acid solution –Profilometer measurements –High pressure water tests –Successful recipe for samples But no success with cavity coating –Still peeling off after high pressure water cleaning –Analysis of x-ray diffraction measurements (DORIS) indicate the presence of two distinguished niobium phases. –Still mechanical problems with cavity shape

Linear Arc coating

WP Report on Deposition HTC Material by UHV Cathodic Arc Several films have been deposited using a niobium cathode in a nitrogen atmosphere. The nitrogen pressure, arc current and voltage bias were varied in order to obtain nitride films with good superconducting properties. Despite the effort the maximum Tc obtained was ~15K with a large transition width. The films were not uniform and presented on the surface aggregates of irregular shape formed in flight. Conclusion: –Due to the extreme criticality of parameters it was concluded that it would be very difficult to obtain the desired nitride cubic phase everywhere on a cavity cell complex geometry surface.

Report on Deposition HTc Material by UHV Cathodic Arc Figure 3 -Transition to the superconducting state of one of the first UHV arc deposited NbN samples. Tc about 15K, ∆Tc ~5K, Fig.6 – Peeling on the anode in the cathodic region

INFN Legnaro: finished 9-cell cavity by spinning

Status seamless cavity by hydroforming Finished since some time –Waiting in cue with many TTF cavities for cold test, now ready for cold test

Summary status JRA-SRF There is no real show stopper Basically all work is finished –Prototypes are fabricated, but not all are measured; is beyond the scope of deliverable High risk tasks have been clearly identified in the Annex1 –Deliverable is de-scoped, some activities continue –Summary report in preparation

Aktenzeichen PCT/EP 2008/ beim Europäischen Patentamt in München HIGHLIGHT 1 Seamless 9-cell cavity by hydroforming

PhD on best EP Parameters Electropolishing without HF HIGHLIGHT 2

JRA-SRF Annual Meeting 08 Not during Annual CARE Meeting at CERN, program is too crowded Scheduled for November 08 as Video conference We need guidelines for the final report ASAP –Draft should be finished until our annual meeting