1. ILC-BCD: Cavity Package International Linear Collider - Baseline Configuration Document: Cavity Package Lutz.Lilje@desy.de DESY -MPY-

2. 14.09.2015Lutz Lilje DESY -MPY- Overview Please look at: –BCD Home http://www.linearcollider.org/wiki/doku.php?id=bcd:bcd_home –Main Linac http://www.linearcollider.org/wiki/doku.php?id=bcd:main_linac: main_linac_home Terminology –BCD: Baseline –ACD: Alternative configuration

3. 14.09.2015Lutz Lilje DESY -MPY- Cavity Package Cavity –Materials –Shape –Fabrication –Preparation Coupler HOM Scheme Tuner Module

4. 14.09.2015Lutz Lilje DESY -MPY- Cavity Materials –BCD: Fine grain –ACD: Large grain serious R&D effort recommended Shape –BCD: TESLA shape Very well know –ACD: Low-loss –serious R&D effort recommended Re-entrant –Multi-cell perceived to be difficult to prepare Superstructure –Would need superconducting seal as preparation for full unit is perceived difficult »R&D effort recommended to develop seal

5. 14.09.2015Lutz Lilje DESY -MPY- Cavity (ctd.) Fabrication –BCD: Electron-beam welding –ACD: Hydroforming. Spinning Work on costing needed Tube fabrication needs R&D Preparation –BCD: 800C furnace + EP + 120 C Bake –serious R&D effort recommended –ACD: 1400 C + EP´+ 120 C bake

6. 14.09.2015Lutz Lilje DESY -MPY- Coupler BCD: TTF III –Very well-known ACD: –Several ideas E.g. 2 KEK designs, LAL disk window

7. 14.09.2015Lutz Lilje DESY -MPY- HOM Scheme BCD: TESLA with minor mods + HOM absorber a la XFEL ACD: demountable rotationally symmetric couplers

8. 14.09.2015Lutz Lilje DESY -MPY- Tuner BCD: none ACD: –Blade –Saclay II XFEL choice Would need modification for more compactness –2 KEK versions

9. 14.09.2015Lutz Lilje DESY -MPY- Module BCD: TTF III+ with modifications –Probably only 8 cavities Are 12 cavities really cheaper (less interconnects etc.) –Quad at the center –Cavity spacing as small as possible BCD: 283 mm Still need space for putting screws….. ACD –Movers on quad –Movers on module –Separate quad from cavity string and put in separate cryostat