Cost reduction activities in cavity fabrication at MHI XR02560 Cost reduction activities in cavity fabrication at MHI F. Inoue K. Okihira, H. Hara, H. Hitomi, K. Kanaoka, T. Yanagisawa, K. Sennyu Nov. 2012 Advanced Mechanical Systems Department

2. Improvement in cavity fabrication method for cost reduction Contents 1. SRF activities at MHI 2. Improvement in cavity fabrication method for cost reduction 3. Cost analysis 4. Summary © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

’06~ ERL Cavity 9 sets ’90~ L-band Cavity ’02~ Crab Cavity 2 sets 1-1 SRF activities at MHI ’05~ STF Cavity 26 sets ’06~ ERL Cavity 9 sets Courtesy of KEK ’90~ L-band Cavity ’02~ Crab Cavity 2 sets ‘86~ Tristan Cavity　36sets © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

1-2 Activities for Improvement of cavity performance In case of KEK STF cavities Cavity No. Assy. Thickness of thinning Shape of groove Bead condition Frequency of chemical polishing Management of cleanness High pressure gas safety law 1.0 #1-4 Horizontal 2.5 mm Butt Bumpy Only after thinning Air duster － 1.5 #5-6 #7-9 2.0 mm Smoother Each step (just before EBW) 　　Clean area #10-11 Step Flatter 2.0 #12-22 More stable top gun Adapted 2-a #23-26 Vertical © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

1-3 Recent result of vertical test for STF cavity Under re-treatment All these cavities are governing high pressure gas safety law in Japan. © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2 Improvement in cavity fabrication method for cost reduction List of our proposed fabrication methods Applied to Production cavities; ・To simplify inner conductor of HOM coupler design ・Seamless beam-pipe (deep-drawing) Applied to R&D cavities(MHI-A,MHI-B); ・Using LBW instead of EBW for stiffener and flange ・Automatic finishing for inner surface of cell ・Seamless dumbbell Applied to R&D cavity(MHI-C); ・Welding the equator line in succession ・Using LBW for baseplate © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2-1 Fabrication of MHI-A cavity Feature ・Deep drawing for HOM cup. ・LBW for stiffener ring and flanges of beam tube. EBW nipple for tuning © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2-2 Fabrication of MHI-B cavity Feature ・ No welding seam on iris and longitudinal line. ・ Finishing for inner surface of dumbbell is auto buffing. Seamless dumbbell This cavity was developed by MHI and KEK, and the VT will be carried out at JLab, soon. Auto buffing © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2-3 Fabrication of MHI-C cavity Feature ・Welding all equator line of cavity in succession by vertical position without purge of vacuum chamber. ・LBW for baseplate. LBW EBW © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2-3 Welding in succession (MHI-C) Before Cavity was welded by horizontal position. 1 or 2 seams of equator are welded in one batch. Welding procedure 1 cavity／5 batches © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2-4 Welding in succession (MHI-C) Cavity is assembled and welded by vertical position. 9 seams of equator are welded in one batch. EBW 4 cavities／1 batch EBW EBW EBW EBW future EBW EBW EBW EBW EBW 1 cavity／1 batch © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2-5 LBW for baseplate (MHI-C) Welding Nb ring and Ti plate by LBW Vacuum condition is not required. Ti vapor is bad for EBW-gun. - no problem by LBW with argon gas shield LBW bead is equivalent to EBW. - Mechanical strength is OK at room temp - now under cold test at KEK Base plate Ti Nb End group LBW © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

2-6 Application of fabrication methods Now , STF #23 ~ #26 cavities are under fabrication. Some fabrication methods will be applied to these cavities. ・Simple design for inner conductor of HOM coupler ・Seamless beam-pipe (deep-drawing) ・Using LBW for stiffener ・Using LBW for baseplate ・Welding the equator line in succession by vertical position © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

3 Cost analysis Next phase, Cost analysis for a cavity without EP process (100 cavities production) (%) Material Mechanical Machining Welding Inspection Sub-total Cavity 32.5 24.5 19.0 5.2 81.2 LHe jacket 4.7 8.0 2.4 3.8 18.8 Sub- total 37.2 21.4 8.9 100 Cost analysis for a cavity without EP process (100 cavities production) (%) Material Mechanical Machining Welding Inspection Sub-total Cavity 32.5 24.5 19.0 5.2 81.2 LHe jacket 4.7 8.0 2.4 3.8 18.8 Sub- total 37.2 21.4 8.9 100 Cost analysis for a cavity without EP process (100 cavities production) (%) Material Mechanical Machining Welding Inspection Sub-total Cavity 32.5 24.5 19.0 5.2 81.2 LHe jacket 4.7 8.0 2.4 3.8 18.8 Sub- total 37.2 21.4 8.9 100 Next phase, we should reduce the cost of material & machining in corporation with KEK. This phase We got some good results for cost reduction of welding. ~40% welding cost reduction from prior method © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

4 Summary We have supplied some 1.3GHz SRF cavities for STF and ERL projects at KEK for the last few years. The cavity performance are improving step by step. We have proposed some ideas for cost reduction and these method was established step by step. We have estimated the effect of cost reduction. For more cost reduction, we need some idea to reduce the volume of material & design for easy machining. MHI-B cavity with seamless dumbbell will be transported to J-Lab for a surfacetreatment and vertical test. MHI-C cavity is under inspection. It will be done a vertical test at KEK next month. © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

E. Kako, K. Watanabe , S. Noguchi, T. Shishido and Y. Yamamoto at KEK Special thanks Special thanks to E. Kako, K. Watanabe , S. Noguchi, T. Shishido and Y. Yamamoto at KEK for STF activities in this presentation © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.

Thank you for your attention ! © 2012 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved.