1. 1 The CNGS Reflector Water distribution system Outer conductor Inner conductor Drain connections  5 Drain tube Support and alignment frame Transport chassis

2. 2 Repair Location in Target Chamber p-beam Target Service Gallery from Access Gallery

3. 3 Leaking Drain Connection Outer conductor (Al) Titanium flanges Ceramic insulator (500V) (brazed to the Ti flanges) Clamps for vapor tightness Rupture point – leak! Bellows to absorb misalignment

4. 4 New Design for Drain Connection Improvements of new design: Stress in ceramic strongly reduced  No brazing  No machined internal edges  Larger and thicker ring  Ceramic under compression (avoids shear & tension) Water and vapour tightness maintained  tightening the ceramic between flanges with bolts  Soft graphite seal Rigorous QA during assembly  Tracing of equipment and record history CNGS Reflector Leak Review Meeting with AB, TS and RP experts, held on 29 Nov 06 Old design (brazed ceramic) New design flanges graphite seals ceramic

5. 5 Improvement on Horn/Reflector Water Inlets Studies on existing system  Stresses due to brazing on ceramic oThin stainless steel foil brazed on ceramic sleeve oThin foil brazed to water tube  Life-time of long bellows One possible new design exists  avoid brazing and bellows for the water inlet Water sprayers surrounded by short bellows Outer conductor Water inlets with insulating ceramic and long bellows Arclex ring

6. 6 Work completed: - Crane maintenance - Maintenance work on the target and safety shutter, upgrade software - Second veto to access system (from safety shutter and horn/reflector) Work in progress: - Improvement of electrical substation in service gallery - Maintenance of ventilation and cooling system - Improvement of ventilation system (leak ventilation during operation) CNGS Shutdown work:

7. 7 Status of Horn and Reflector Repair & Improvements: Detailed schedule for improvements, installation and tests exists Following final validation of the modifications, interventions and tests on the horn and reflector will be done in July & August. Target date: The schedule aims to have the CNGS facility ready for first tests with beam (i.e. continuation of the October 2006 plan) by mid September 2007 to start the final commissioning at nominal performance.