1. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 1 LHCb upgrade: thin VELO RF shield  Thinning by chemical etching –an investigation on a backup solution, in case fabrication of 0.2mm RF boxes is not possible in the given time scale.  New solutions ? –3D printing –electromagnetic forming

2. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 2 Thinning by chemical etching The idea is to «post-process» the RF box  a box is produced in Amsterdam  suppose the achievable thickness is larger than 0.2mm: can we thin down the most relevant area of the RF box ?  CERN (TE-VSC) has the infrastructure/labs to make chemical etching of large objects such as our RF box –Start investigations with NaOH –How well can the thickness be locally controlled on complex ciorrugated shapes ? –Microleaks ?  After etching, the box must be coated with Torlon and NEG (heat treaments!)

3. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 3 what needs to be thinned ?  Most particles do not at all go through the side corrugations!  Only this region needs to be thinned down ~20cm

4. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 4 R&D programme at CERN  Design a small sample RF foil with chuck/support  Produce it by precision machining –aim for 0.2 or 0.3mm  Metrologize, vacuum-test  Etch  Metrologize, vacuum-test we are about to start about 20cm

5. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 5 The sample foil

6. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 6Chuck/support

7. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 7Chuck/support

8. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 8 3D printing  Contacted belgian company Layerwise  They specialize in high-tech 3D metallic printinting (medical, aerospace,...)  They normally use Ti, but can do other metals (incl. Al)  They visited us at CERN, saw the prototype Amsterdam RF box, and... winced. –They need a good/solid starting surface, then print up vertically (this could be the back side of the box) –The inclinations should not be more than about 30 deg from the vertical –They never made such a large thin piece, though they are developing machinery for that (would be on time scale of 1-2 years) –They have much experience with Ti, less with Al... (they were proposing, if we go on, to make a small prototype of Ti)  Will send us the design rules, but I have little hope for this route –Could be more realistic if we would split the box in 2 or 3 elements

9. RF shield thinning17/05/2013CERNMassimiliano Ferro-Luzzi 9 Electromagnetic pulse forming/welding  We had a visit from specialized company  An interesting method, similar to explosive forming, but without springback  One could perhaps start from a simple flat-walled box and obtain corrugated shape by this electrohydraulic forming (immersion and «instantaneous» electromagnetic pulse)  CERN TE is interested.  Will have more technical discussion in June