1. J.C. Sheppard, SLAC Americas Region September 28, 2006 1 ILC Positron TDR and R&D Collaboration Meeting 1: Oxford GigaZ and Polarization Upgrade Discussion J. C. Sheppard SLAC September 28, 2006

2. J.C. Sheppard, SLAC Americas Region September 28, 2006 2 GigaZ Upgrade GigaZ: What are beam requirements? Emittance, Energy Spread, Rate, Polarization? Which Source: The undulator source of course Polarization: 60% Three options: (a)Decelerate: full rep rate; medium emittance dilution; largest energy spread; minimum energy jitter; no additional hardware costs (b)Drift thru linac: ½ rep rate; largest emittance dilution; larger energy spread; max energy jitter; no additional hardware costs (c)Bypass Line: Extract and Drift to IP in beam tube: ½ rep rate; smallest emittance dilution; smallest energy spread (?); max energy jitter; additional hardware costs It’s a numbers game which can be simulated…….  E /Eand  E/E ~0.1%; also need spec on transverse emittance

3. J.C. Sheppard, SLAC Americas Region September 28, 2006 3 GigaZ Upgrade Polarization Upgrade: What, how much, how long? What: ~100 m of undulator; photon collimator; spin rotators; makeup rf; extra cryo plant How much: several 10’s M$ How long: 3 month downtime if you are organized, may be 1-2 year lead time to acquire hardware