3-March-06ILCSC Technical Highights1 ILC Technical Highlights Superconducting RF Main Linac.

3-March-06 ILCSC Technical Highights 1

main linacbunchcompressor

dampingring

source

pre-accelerator

collimation

final focus

IP

extraction& dump

KeV

few GeV

few GeVfew GeV

250-500 GeV

ILC Technical Highlights

Superconducting RF Main Linac


Parametric Approach

• A working space - optimize machine for cost/performance


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


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)


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


ILC Small Damping Ring

Multi-Bunch Trains with inter-train gaps


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.


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


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


Superconducting RF Cavities

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


Improved ProcessingElectropolishing

Chemical Polish

Electro Polish


Increasediameter beyond X-FEL

Increasediameter beyond X-FEL

Review 2-phase pipe size and effect of slope

ILC Cryomodule


RF Power: Baseline Klystrons

Thales CPI Toshiba

Specification:

10MW MBK

1.5ms pulse

65% efficiency


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


• Large Scale 4detectors with solenoidal magnetic fields.

• In order to take full advantage of the ILC ability to reconstruct, need to improve resolutions, tracking, etc by factor of two or three

• New techniques in calorimetry, granularity of readout etc being developed

Detectors for the ILC

3-March-06ILCSC Technical Highights1 ILC Technical Highlights Superconducting RF Main Linac.

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