1. Discussion for Keep Alive Source /Auxiliary Positron Source KURIKI Masao Hiroshima U. /KEK 10/25/2011 ILC Technical Baseline Review, 2011, DESY 1

2. KAS/APS central region integral KAS/APS share a common target, capture, booster. 500 MeV linac for KAS/APS is in e- BDS tunnel. KAS/APS operation conflicts to maintenance in e- BDS, e- RTML (upstream), and e- DR. KAS/APS is compatible with maintenance for e- RTML (downstream), e- ML, and undulator. 10/25/2011ILC Technical Baseline Review, 2011, DESY 2

3. BDS DOGLEG and AUX SOURCE 10/25/2011 3 ILC Technical Baseline Review, 2011, DESY Electron Beam For Aux. Positron

4. TGT, OMD, etc and Vault 10/25/2011 4 ILC Technical Baseline Review, 2011, DESY Aux. Positron Electron Beam For Aux. Positron

5. 125 MeV Capture Accelerator, Beam separation and Dumps 10/25/2011 5 ILC Technical Baseline Review, 2011, DESY Aux. Positron (Injector Linac)

6. 5 GeV Booster and BDS Optics 10/25/2011 6 ILC Technical Baseline Review, 2011, DESY Aux. Positron (5GeV Booster)

7. Continued BDS and E+ transport past the MAIN 20 MW E+ DUMP 10/25/2011 7 ILC Technical Baseline Review, 2011, DESY Aux. Positron

8. Separation of E+ Beam to DR and E- BDS to IR + E- RTML 10/25/2011 8 ILC Technical Baseline Review, 2011, DESY

9. Concept of “Auxiliary” or “Keep Alive Source 1.RDR Keep Alive source: 10% nominal intensity. 1.Dedicated 500MeV e- linac 2.Dedicated e+ target (W or W-Re) and capture section. 2.SB2009 Auxiliary source: 2% intensity 1.Dedicated 500MeV e- linac 2.A common e+ target (Ti alloy) and capture with undulator. 3.Placed in BDS tunnel. 3.Is SB2009 Auxiliary source useful? 9 10/25/2011 ILC Technical Baseline Review, 2011, DESY

10. KAS/APS yield 500 MeV driver with 0.4X 0 target makes ~2% intensity. The same driver with 3X 0 target makes ~20% intensity. 0.4X 0 Ti alloy and 4X 0 W has same thickness. 10/25/2011 ILC Technical Baseline Review, 2011, DESY 10

11. Two Scenarios Start up e+ source is very important in MD phase. In the initial phase, 3X 0 W-Re instead of 0.4X 0 Ti alloy improves the e+ intensity. 500 MeV single bunch S-band accelerator (30m) can generate 20 % intensity e+ beam. The target can be replaced when undulator is ready for the commissioning. KAS becomes a small backup with a few % intensity. Could W-Re (or W) and Ti alloy be implemented in a same target ? (Hybrid). 10/25/2011ILC Technical Baseline Review, 2011, DESY 11

12. Mosaic target A target assembly consists from W-Re and Ti-alloy. The target should be assembled symmetrically for smooth rotation. The rotation is controlled, so that electron hit W-Re part and photon hit Ti-alloy part. The target is compatible both for physics run with undulator and commissioning run with e- auxiliary source, without target exchange. 10/25/2011ILC Technial Baseline Review, 2011, DESY 12 Ti W-Re photon electron

13. Summary Any conflict with other system in operation? Does it work really as KAS/APS? Is 2% bunch intensity enough? Target replace after commissioning phase seems to be efficient and reasonable. Mosaic target can be a technical solution to avoid the target exchange. 10/25/2011ILC Technical Baseline Review, 2011, DESY 13