1. VELO RF box status at Nikhef Report at the Meeting for new VELO RF foil development Tjeerd Ketel, Erno Roeland a.o., Nikhef 29-03-20111Tjeerd Ketel, Nikhef

2. Activities in 2010 After a failure in February 2010 to produce a complete leak-tight RF box, we decided to produce a flat box to save on prepared foils. – Longer foil extension (4 mm) for welding. – Improvements welding machine. – More flanges (4) milled at the VU. – Inventory of the side foils. More manpower promised in May. – New welding machine. Optimization to avoid tiny cracks (leaks) at long welds. Flat box is tested in October. It leaks at all corners! – Corner tests started. – First additional foil pressed at Nikhef. 29-03-2011Tjeerd Ketel, Nikhef2

3. Activities in 2011 Prepare side foils for 10 boxes (40 in total). – Ready minus 2 side foils. Prepare 7 left and 7 right RF foils. – Still 3+3 to be pressed. Produce 6 test cubes (48 corners). – Improvements in first welds. – Improvements in repair, including AlSi addition. Produce complete RF boxes. – First in preparation. 29-03-2011Tjeerd Ketel, Nikhef3

4. The test cubes 1234 56 29-03-20114Tjeerd Ketel, Nikhef

5. Cubes 1-6 Cube 1: – Test of flat foils, without good cooling contact. Cube 2: – 12A. All corners bad. Both solder and weld added. Repair failed Cube 3: – 17A. All corners bad. Little cracks. Repairs failed. Cube 4: – 19A. Three corners bad. Weld added. One repaired. – Continue with 19 A for the rest. Cube 5. – One corner bad. Welded again. Still small leak. Cube 6. – Four corners bad. AlSi added. Three repaired. One small leak. 29-03-20115Tjeerd Ketel, Nikhef

6. Cubes 5-6 29-03-2011Tjeerd Ketel, Nikhef6

7. RF box 29-03-2011Tjeerd Ketel, Nikhef7

8. Conclusion and outlook Cube tests improved the welding quality and showed repair with welding AlSi wire. Start now with a real box. Improve on repair simultaneously. Production rate of one box per month, foreseen but not yet realized. 29-03-20118Tjeerd Ketel, Nikhef