Status and Plan of GDE Design Work (Including Road Map for RDR) Feb. 17 2006 PAL Eun-San Kim

ILC Meetings Snowmass, Colorado, 14-17 Aug. 2005 : Started BCD European GDE meeting, Oxford, 25 Oct. 2005 Damping ring workshop, CERN, 9-11 Nov. 2005 GDE meeting, Frascati, Italy 7-9 Dec. 2005 : Decided BCD 1st Area System meeting, KEK, 19-20 Jan. 2006 : Discussed machine layout and boundary between area systems Lattice design meeting, CERN, 6-8 Feb. 2006 2nd Area System meeting, FNAL, 13-14 Feb. 2006 GDE meeting, Bangalore, 9-11 March 2006 3rd Area system meeting, DESY, April 2006 GDE meeting, Vancouver, 19-23 July 2006 GDE meeting, Valencia, Autumn 2006

Frascati GDE Meeting Discussed progress since Snowmass Finally agreed BCD to be documented. - includes baseline and alternative designs Organized the GDE group for RDR in 2006 Final BCD becomes property of CCB in early 2006

Frascati GDE Meeting BCD layout IP Working Group for BCD WG1 : LET beam dynamics WG2 : Main Linac WG3a : Sources WG3b : Damping Rings WG4 : Beam Delivery WG5 : SCRF Cavity IP

Frascati GDE Meeting Matrix group for RDR C. Adolphsen H. Hayano L. Lilje N. Solyak J. Gao S. Guiducci A. Wolski D. A-K A. Seryi H. Yamamoto M. Kuriki J. Sheppard E.-S. Kim P. Tenenbaum A. Brachmann Area system is geographical breakdown of machine for design and cost estimation A. Brachmann

1st Area system meeting Baseline Layout (500 GeV) 1st stage - 1st stage : 500 GeV - 2nd stage : 1 TeV ; Moving of turn-around and BC No moving of DR

Electron source in BCD laser 120 keV DC Gun 70-100 MeV 400 MeV SC Linac Eacc = 17.8 MV/m NC pre-accelerator diagnostic section NC SHB+solenoid 70-100 MeV

Positron source in BCD To IP Undulator ~100m e- Accelerating structure To DR Ti Alloy target 150 GeV e- Ti Alloy Target

Damping Ring in BCD Baseline e+ : two 6 km rings Alternative e- : one 6 km ring Alternative e+ : 6 km, 17 km OCS Baseline

DR Tasks List for RDR Lattice design - 6 km e-/e+ rings : L. Emery, A. Xiao, E-S Kim, Y. Sun - 17 km e-/e+ rings : Y. Cai, Y. Yan - Injection and extraction lines : A. Wolski Acceptance : Y. Cai, Y. Yan, A.Wolski Low-emittance tuning : J. Jones Impedance : M. Venturini, K. Bane, S. Heifets, etc Electron-cloud : M. Pivi, C. Celata, K. Ohmi etc.

DR Tasks List for RDR Ion-effects Other collective effects : L. Wang, E-S Kim, K. Ohmi, M. Venturini, G. Xia Other collective effects : S. Mtingwa, M. Venturini, S. Santis, A. Wolski Injection/extraction kickers : pulser : J. Urakawa, T. Naito, M. Ross, A. Krasnykh, etc Injection/extraction kickers : striplines : A. Krasnykh, S. Santis, D. Alesini, F. Marcellini

Baseline Damping Ring Circumference 6.6 km Energy 5 GeV RF frequency 650 MHz Harmonic number 14402 Damping time < 25 ms (e+) < 50 ms (e-) Emittance 5 mm Bunch length 6 mm Energy spread < 0.13 % Momentum compaction 4x10-4 Damping wiggler peak field 1.6 T Damping wiggler period 0.4 m Energy acceptance < 0.5 % Dynamic aperture Ax+Ay < 0.09 m-rad Baseline configuration lattice Specifications

Baseline Damping Ring Bunch filling patterns for e-

Fast-ion effects in Baseline Damping Ring 650 MHz, 5400 bunch Beam size Sqrt(Jy) per 50 turns 50 turns

Lattice Design of Electron damping ring One straight section One Arc and Wiggler section A lattice with low average beta-functions to reduce the effects of fast-ion. Tele-conference for e- DR lattice will be at the beginning of March.

Ring to Main Linac (RTML) Status and Plans Started works for shorter bunch compressor and turn-around optics Contacted leaders of all technical and global systems Milestone - Review RTML design and place lattices and documentation under change control in April 2006

Ring to Main Linac (RTML) RTML Layout Turn around eny = 0.02 mm, 3.2 nC, sz = 6mm Total 2.5 km Bunch compressor sz = 0.15 mm SR BC 1 BC 2

Ring to Main Linac (RTML) Bunch compressor Alternative Baseline Chicane 68.4 m 480 m Matching 4 m 310 m Number of RF cavity 452 488 Total length 680 m 1400 m Alternative Baseline Required bunch length achieved System length shorter longer Tolerence of emittance acceptable comparable BCD alternative baseline GDE Requirement correction of vertical dispersion shorten system length

Ring to Main Linac (RTML) Bunch compressor Each BC in baseline has 240 meters of bend magnets arranged in chicanes : Long ! Considering two approaches to reduce length Enhancing R56 by forcing nonzero dispersion at Qs Replacing wiggler with 4-bend chicane with optimized lattice functions for emittance preservation

Main Linac in BCD Baseline in 1st stage - TESLA cavity type - Operation gradient = 31.5 MV/m, Qo=1010 Baseline in 2nd stage - LL or RE cavity type - Operation gradient = 36 MV/m, Qo=1010 - Total length = 41 km Alternative in 1st stage - LL or RE cavity type - Operation gradient = 36 MV/m Linac RF basic unit - 1 modulator, 1 klystron, 3 cryomodules, 27 cavities

Beam Delivery System in BCD Baseline : - 2 IPs for 2 mrad and 20 mard - 150 m longitudinal separation between 2 IPs Alternative : - 1 IP 2 Interaction Point

Summary Bangalore GDE meeting - starting for estimation of costs RDR will be finished in Dec. 2006 - RDR is not complete technical design, but is a design to estimate reliable cost. TDR will be completed in Dec. 2008.