Baseline Configuration Highlights Barry Barish ILCSC 9 Feb06

Baseline Configuration - Highlights Barry Barish ILCSC 9 -Feb-06 ILCSC

The Key Decisions Critical choices: luminosity parameters & gradient 9 -Feb-06 ILCSC 2

Making Choices – The Tradeoffs Many decisions are interrelated and require input from several WG/GG groups 9 -Feb-06 ILCSC 3

The Baseline Machine (500 Ge. V) ~30 km RTML ~1. 6 km ML ~10 km (G = 31. 5 MV/m) 20 mr 2 mr BDS 5 km e+ undulator @ 150 Ge. V (~1. 2 km) x 2 R = 955 m E = 5 Ge. V not to scale 9 -Feb-06 ILCSC 4

Parametric Approach • A working space - optimize machine for cost/performance 9 -Feb-06 ILCSC 5

Electron Source • DC Guns incorporating photocathode illuminated by a Ti: Sapphire drive laser. • Long electron microbunches (~2 ns) are bunched in a bunching section • Accelerated in a room temperature linac to about 100 Me. V and SRF linac to 5 Ge. V. laser E=70 -100 Me. V Positron-style roomstandard ILC temperature SCRF modules accelerating section diagnostics section sub-harmonic bunchers + solenoids 9 -Feb-06 ILCSC 6

Positron Source Helical Undulator Based Positron Source with Keep Alive System Primary esource Beam Delivery System e. DR 150 Ge. V 100 Ge. V Helical Undulator In By-Pass Line Auxiliary e. Source Positron Linac IP Photon Collimators 250 Ge. V e+ DR Target e. Dump Photon Beam Dump Photon Target Adiabatic Matching Device e+ preaccelerator ~5 Ge. V Keep Alive: This source would have all bunches filled to 10% of nominal intensity. 9 -Feb-06 ILCSC 7

ILC Small Damping Ring Multi-Bunch Trains with inter-train gaps 9 -Feb-06 ILCSC 8

ILC Damping Ring: Baseline Design • Positrons: – Two rings of ~6 km circumference in a single tunnel. – Two rings are needed to reduce ecloud effects unless significant progress can be made with mitigation techniques. – Preferred to 17 km dogbone due to: • Space-charge effects • Acceptance • Tunnel layout (commissioning time, stray fields) • Electrons: – One 6 km ring. 9 -Feb-06 ILCSC 9

Main Linac: SRF Cavity Gradient Cavity type initial upgrade Qualified gradient Operational gradient Length* energy MV/m Km Ge. V TESLA 35 31. 5 10. 6 250 LL 40 36. 0 +9. 3 500 Total length of one 500 Ge. V linac 20 km 9 -Feb-06 ILCSC * assuming 75% fill factor 10

Cavity: R&D • Material R&D: Fine, Large, Single Crystal • Fabrication – A number of minor modifications and improvements could be implemented without impact to the basic cavity design. • Cavity Preparation • Buffer Chemical Processing • Cavity Processing (strong R&D needed) – Electro-polishing (EP) System – High Pressure Rinsing (HPR) – Assembly Procedure 9 -Feb-06 ILCSC 11

Superconducting RF Cavities High Gradient Accelerator 35 MV/meter -- 40 km linear collider 9 -Feb-06 ILCSC 12

Improved Processing Electropolishing Chemical Polish Electro Polish 9 -Feb-06 ILCSC 13

RF Power: Modulator Baseline Alternate Operation: an array of capacitors is charged in parallel, discharged in series. (~2 m) The Bouncer Compensated Pulse Transformer Style Modulator 9 -Feb-06 Will test full prototype in 2006 ILCSC 14

RF Power: Baseline Klystrons Specification: 10 MW MBK 1. 5 ms pulse 65% efficiency Thales 9 -Feb-06 CPI Toshiba ILCSC 15

ILC Cryomodule Increase diameter beyond X-FEL Review 2 -phase pipe size and effect of slope 9 -Feb-06 ILCSC 16

ILC Beam Delivery System • Baseline (supported, at the moment, by GDE exec) – two BDSs, 20/2 mrad, 2 detectors, 2 longitudinally separated IR halls • Alternative 1 – two BDSs, 20/2 mrad, 2 detectors in single IR hall @ Z=0 • Alternative 2 – single IR/BDS, collider hall long enough for two push-pull detectors 9 -Feb-06 ILCSC 17

Conclusions -- BCD • The baseline configuration for the ILC has been established and is document in the BCD (a 700+ page electronic document) • We have put the BCD under configuration control and are evolving it now in a controlled manner • The BCD also defines alternatives and the combination of the baseline and alternative will give good guidance for the ILC R&D program • The BCD is now being used as the starting point and basis for the reference design / cost effort this year. 9 -Feb-06 ILCSC 18