On the Way to ILC

Shekhar Mishra

Fermilab Talk presented on behalf of ILC-GDE 2/16/06 Talk Presented at the 2006 Aspen Winter Conference: "Particle Physics at the Verge of Discovery"

International Linear Collider: Performance Specification (White Paper) – Initial maximum energy of

500 GeV

, operable over the range 200-500 GeV for physics running.

– Equivalent (scaled by 500 GeV/  s) integrated luminosity for the first four years after commissioning of

500 fb -1

.

– Ability to perform energy scans with minimal changeover times.

– Beam energy stability and precision of 0.1%.

– Capability of

80%

electron beam

polarization

over the range 200-500 GeV. –

Two interaction regions

, at least one of which allows for a crossing angle

enabling

gg

collisions

.

– Ability to operate at

90 GeV

for calibration running.

– Machine upgradeable to approximately

1 TeV

.

Road to: Reference Design Report

ITRP Recommendation (Aug 2004) : Superconducting RF is accelerating technology for ILC • 1 st ILC Workshop at KEK (11/2004) – working groups (WG) formed to begin identifying contentious design issues • 2 nd ILC Workshop Snowmass (8/2005) – modified WG continue identifying baseline design and alternatives – newly formed ‘Global Groups’ begin to discuss and catalogue global design issues – 2 nd Snowmass week: concentrate on the list of ‘Top 40’ critical design questions • 1 st Meeting of the ILC-GDE (12/2005) – Acceptance of the Baseline Configuration Document (BCD) – Start work towards the Reference Design Report (12/2006, with Cost) – Formation of Accelerator System, Technology and Global systems – Formation of • Design and Cost Board, Change Control Board and R&D Board

GDE RDR / R&D Organization

ICFA FALC GDE R & D Board ILCSC FALC Resource Board GDE Directorate GDE Executive Committee GDE Change Control Board

GDE

GDE Design Cost Board Global R&D Program RDR Design Matrix

GDE RDR / R&D Organization

ICFA FALC GDE R & D Board ILCSC FALC Resource Board GDE Directorate GDE Executive Committee GDE Change Control Board GDE Design Cost Board

ILC R&D Program

Global R&D Program RDR Design Matrix

ILC Design Effort

Mission of Global Design Effort

• Produce a design for the ILC that includes – A detailed design concept – Performance assessments – Reliable international costing – An industrialization plan – Siting analysis – Detector concepts and scope • Coordinate worldwide prioritized proposal driven R & D efforts – To demonstrate and improve the performance – Reduce the costs – Attain the required reliability, etc.

The Baseline Machine (500GeV)

20mr ~30 km ML ~10km (G = 31.5MV/m) RTML ~1.6km

2mr BDS 5km R = 955m E = 5 GeV e+ undulator @ 150 GeV (~1.2km) x2 not to scale

Bunch charge N Number of bunches n b Linac bunch interval Bunch length t b s z Vertical emittance ge y IP beta (500GeV) b x IP beta (1TeV) b y b x b y

Luminosity Table

min nom max 1 2 2 1330 2820

5640

x10^10

154 150 0.03

10 0.2

10 0.2

308 461 ns 300 500 m m 0.04 0.08 mm.mrad

21 21 mm 0.4

30 0.3

0.4

30 0.6

mm mm mm

Baseline 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 MeV and SRF linac to 5 GeV.

DC gun(s) laser E=70-100 MeV Positron-style room temperature accelerating section standard ILC SCRF modules sub-harmonic bunchers + solenoids diagnostics section

Baseline Positron Source

• Helical Undulator Based Positron Source with Keep Alive System – The undulator source will be placed at the 150 GeV point in main electron linac.

Primary e -

• This will allow constant charge operation across the foreseen

source

centre-of-mass energy operating range.

e DR 150 GeV Helical Undulator In By-Pass Line Beam Delivery System 100 GeV Photon Collimators Target e Dump IP Photon Beam Dump Auxiliary e Source Photon Target Adiabatic Matching Device Positron Linac 250 GeV e + pre accelerator ~5GeV e + DR

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 due to: –Space-charge effects –Acceptance –Tunnel layout (commissioning time, stray fields) •

Electrons:

one 6 km ring.

• Preferred to 3 km due to: –Larger gaps between mini-trains for clearing ions.

–Injection and extraction kickers ‘low risk’

Main Linac: Baseline RF Unit

SRF Cavity Gradient

initial upgrade Cavity type Qualified gradient MV/m Operational gradient MV/m Length* Km energy GeV TESLA 35 31.5

10.6

250 LL 40 36.0

+9.3

500 * assuming 75% fill factor Total length of one 500 GeV linac  20km

Baseline ILC Cryomodule

• The baseline ILC Cryomodule will have 8 9-Cell cavities per cryomodule. The quadrupole will be at the center in the baseline design.

• Every 4 th cryomodule in the linac would include a quadrupole with a corrector and BPM package.

Baseline

Modulator

Alternate 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

RF Power: Baseline Klystrons

Specification: 10MW MBK 1.5ms pulse 65% efficiency Thales CPI Toshiba ILC (XFEL @ DESY) has a very limited experience with these Klystrons. Production and operation of these Klystron are issues that needs to be addressed.

Beam Delivery System: Baseline & Alternatives

• 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

Jan Frascati

From Baseline to a RDR

Bangalore July Vancouver Valencia Dec 2006 Freeze Configuration Organize for RDR Review Design/Cost Methodology Review Initial Design / Cost Design and Costing Review Final Design / Cost RDR Document Release RDR

ILC R&D

• Major laboratories around the world are working on the ILC Accelerator R&D.

– Europe • DESY (TESLA) (55 Institutions) • European XFEL • CARE (11 Institutions) • EuroTeV (27 Institutions) • UK-LCABD (15 Institutions) – Americas (9 Laboratories and Universities) • Fermilab • SLAC – Asia (6 Institution in 5 countries) • KEK Some Highlights of R&D Activities

Key Issues: ILC Main Linac Accelerator Technology

• The feasibility demonstration for the ILC requires that a cryomodule be assembled and tested at the design gradient of 35 MV/m . – Cavity technology development to routinely achieve > 35 MV/m and Q ~0.5 1e10, • Finalize the design of an RF Unit and evaluate the reliability issues. It is important to fully test the basic building block of the Linac.

• High Power Coupler, HOM, Tuner etc. • 10 MWatt Multi-Beam Klystron, Fabrication, Operation and reliability • RF Distribution, Controls and LLRF • Instrumentation and Feedback • Quadrupole, Corrector and Instrumentation package • Cryogenic Distribution

Europe: ILC R&D • DESY is leading the ILC R&D in Europe. The XFEL at DESY uses ILC Technology and have common R&D goals.

– Cavity Gradient – Industrial studies and development of Main Linac Components.

• Coupler • RF Power • Cryogenics (LHC) • Instrumentation • Beam Delivery System

DESY: ILC Accelerator Modules in Operation RF gun Diagnostics Laser 5 MeV Bunch Compressor Accelerating Structures Bunch Compressor 445 MeV Collimator Undulators bypass FEL diagnostics

At present DESY is operating modules 2* ACC1 Febr 04 1* ACC2 June 02 3* 4 5 ACC3 ACC4 ACC5 April 03 April 03 April 03

250 m In single cavity measurements 6 out of 8 cavities reach 30 MV/m!

ACC5

ILC R&D at Fermilab

• ILC R&D effort at Fermilab is focused on key design & technical issues in support of the RDR, cost estimate and eventually the CDR for the ILC.

• We also have the goal of positioning the Americas to host the ILC at Fermilab • Our efforts are focused on two main areas of the ILC – Main Linac Design – Civil and Site Development • Main Linac R&D: – The goals are to demonstrate the feasibility of all Main Linac technical components, develop engineering designs, estimate costs, explore cost reduction, and engage US industry • Civil and Site Development – Fermilab is working with the GDE and international partners to develop a matrix for comparing possible ILC sites – We also work to develop U.S. sites on or near Fermilab

ILC 1.3 GHz Cavities @ FNAL

Bead pull RF Testing @ FNAL Joint ANL/FNAL BCP/EP Facility 4 cavities received from ACCEL 4 cavities on order at AES 4 cavities expected from KEK

• Industrial fabrication of cavities.

• BCP and vertical testing at Cornell (25 MV/m) • EP and vertical testing at TJNL. ( 35 MV/m) • Joint BCP/EP facility being developed ANL (late 06) • High Power Horizontal test facility @ FNAL (ILCTA-MDB) • Vertical test facility under development @ FNAL ( IB1) • Single/large Crystal cavity development with TJNL

Nb Discs Jlab: Large Grain/Single Crystal Niobium LL cavity 2.3GHz

E peak /E acc = 2.072

H peak /E acc = 3.56 mT/MV/m 1E+11 Baseline After 120 C, 24 h bake T = 2 K 1E+10 1E+09 0 5 10 15 20 25 30

E acc [MV/m]

35 40 45 50

SLAC: Accelerator Design (RDR) • Strong efforts throughout the design effort

– Electron and positron sources – Contributions to the damping rings and RMTL – Main linac design and instrumentation – Rf sources – Beam Delivery System – Civil construction and conventional facilities

• Able to provide leadership for some RDR Area Sub-systems

SLAC: ILC R&D Program • Broad R&D Program (cont.)

– Linac rf sources • Marx generator modulator

Positron capture structures 12 KV Marx Cell

– Electron and Positron sources • NC structure, E-166, electron laser, and cathode

SEY Test Chamber for PEP-II

– Damping rings • SEY studies in PEP-II

KEK: ILC Activities Highlights

KEK ATF Facility for DR and FF

KEK: Main Linac RF Unit R&D

Goal: Achieve Higher Gradient >40 MV/m in a new Cavity Design

Summary

• After the technology selection the ILC Collaboration has made considerable progress towards the design of the ILC.

• The Baseline and Alternate design for each major Accelerator subsystems were defined at Snowmass 2005.

• The ILC-GDE has a approved the Baseline Configuration Document.

• The ILC-GDE is developing the ILC Reference Design Report, with cost estimate. It is expected to be done by the end of CY06 • The ILC R&D around the world is moving fast with focus on key Accelerator Issues.