Baseline Configuration - Highlights

Barry BarishILCSC9-Feb-06

9-Feb-06 ILCSC 2

The Key Decisions

Critical choices: luminosity parameters & gradient

9-Feb-06 ILCSC 3

Making Choices – The Tradeoffs

Many decisions are interrelated and require input from several WG/GG groups

9-Feb-06 ILCSC 4

The Baseline Machine (500GeV)

not to scale

~30 km

e+ undulator @ 150 GeV (~1.2km)x2R = 955m

E = 5 GeV

RTML ~1.6km

ML ~10km (G = 31.5MV/m)20mr

2mrBDS 5km

9-Feb-06 ILCSC 5

Parametric Approach

• A working space - optimize machine for cost/performance

9-Feb-06 ILCSC 6

Electron Source

Positron-style room-temperature

accelerating section

diagnostics section

standard ILC SCRF modules

sub-harmonic bunchers + solenoids

laser E=70-100 MeV

• 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 MeV and SRF linac to 5 GeV.

DC gun(s)

9-Feb-06 ILCSC 7

Positron Source

Primary e-

source

e-

DR

Target e- Dump

Photon Beam Dump

e+

DR

Auxiliary e- Source

Photon Collimators

Adiabatic Matching

Device

e+ pre-accelerator

~5GeV

150 GeV 100 GeV

HelicalUndulatorIn By-Pass

Line

PhotonTarget

250 GeV

Positron Linac

IP

Beam Delivery System

Keep Alive: This source would have all bunches filled to 10% of nominal intensity.

Helical Undulator Based Positron Source with Keep Alive System

9-Feb-06 ILCSC 8

ILC Small Damping Ring

Multi-Bunch Trains with inter-train gaps

9-Feb-06 ILCSC 9

ILC Damping Ring: Baseline Design

• Positrons: – Two rings of ~6 km circumference in a single tunnel.

– Two rings are needed to reduce e-cloud 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 10

Main Linac: SRF Cavity Gradient

Cavity type

Qualifiedgradient

Operational gradient

Length* energy

MV/m MV/m Km GeV

initial TESLA 35 31.5 10.6 250

upgrade LL 40 36.0 +9.3 500

* assuming 75% fill factorTotal length of one 500 GeV linac 20km

9-Feb-06 ILCSC 11

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 12

Superconducting RF Cavities

High Gradient Accelerator35 MV/meter -- 40 km linear collider

9-Feb-06 ILCSC 13

Improved ProcessingElectropolishing

Chemical Polish

Electro Polish

9-Feb-06 ILCSC 14

RF Power: Modulator

BaselineAlternate

The Bouncer Compensated Pulse Transformer Style Modulator

Operation: an array of capacitors is charged in parallel, discharged in series. (~2m)

Will test full prototype in 2006

9-Feb-06 ILCSC 15

RF Power: Baseline Klystrons

Thales CPI Toshiba

Specification:

10MW MBK

1.5ms pulse

65% efficiency

9-Feb-06 ILCSC 16

Increasediameter beyond X-FEL

Increasediameter beyond X-FEL

Review 2-phase pipe size and effect of slope

ILC Cryomodule

9-Feb-06 ILCSC 17

ILC Beam Delivery System

• Baseline (supported, at the moment, by GDE exec)– two BDSs, 20/2mrad, 2 detectors, 2 longitudinally separated IR halls

• Alternative 1– two BDSs, 20/2mrad, 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 18

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.