International Linear Colllider Global Design Effort Barry Barish SLAC ILC Group 5-May-05
SLAC2 Starting Point Superconducting RF Main Linac
5-May-05SLAC3 “Target” Parameters for the ILC E cm adjustable from 200 – 500 GeV Luminosity ∫ Ldt = 500 fb -1 in 4 years Ability to scan between 200 and 500 GeV Energy stability and precision below 0.1% Electron polarization of at least 80% The machine must be upgradeable to 1 TeV
5-May-05SLAC4 TESLA Concept The main linacs based on 1.3 GHz superconducting technology operating at 2 K. The cryoplant, is of a size comparable to that of the LHC, consisting of seven subsystems strung along the machines every 5 km.
5-May-05SLAC5 TESLA Cavity RF accelerator structures consist of close to 21,000 9-cell niobium cavities operating at gradients of 23.8 MV/m (unloaded as well as beam loaded) for 500 GeV c.m. operation. The rf pulse length is 1370 µs and the repetition rate is 5 Hz. At a later stage, the machine energy may be upgraded to 800 GeV c.m. by raising the gradient to 35 MV/m.
5-May-05SLAC6 TESLA Single Tunnel Layout The TESLA cavities are supplied with rf power in groups of 36 by MW klystrons and modulators.
5-May-05SLAC7 Reference Points for the ILC Design 33km 47 km TESLA TDR 500 GeV (800 GeV) US Options Study 500 GeV (1 TeV)
5-May-05SLAC8 Experimental Test Facility - KEK Prototype Damping Ring for X-band Linear Collider Development of Beam Instrumentation and Control
5-May-05SLAC9 Evaluation: Technical Issues
5-May-05SLAC10 TESLA Test Facility Linac laser driven electron gun photon beam diagnostics undulator bunch compressor superconducting accelerator modules pre- accelerator e - beam diagnostics 240 MeV120 MeV16 MeV4 MeV
5-May-05SLAC11 ILC Design Issues First Consideration : Physics Reach ILC Parameters Energy Reach Luminosity
5-May-05SLAC12 Working Parameter Set “Point Design”
5-May-05SLAC13 GDE will do a “Parametric” Design nomlow Nlrg Ylow P N nbnb e x,y mm, nm 9.6, 4010,3012,8010,35 b x,y cm, mm 2, , 0.21, 0.41, 0.2 s x,y nm 543, , , 8452, 3.8 DyDy d BS % szsz mm P beam MW L Range of parameters design to achieve 210 34
5-May-05SLAC14 Maximum Luminosity nomlow Nlrg Ylow PHigh L N nbnb x,y m, nm 9.6, 4010,3012,8010,3510,30 x,y cm, mm 2, , 0.21, 0.41, 0.2 x,y nm 543, , , 8452, , 3.5 DyDy BS % zz mm P beam MW L !
5-May-05SLAC15 Towards the ILC Baseline Design
5-May-05SLAC16 TESLA Cost Estimate 3,136 M€ (no contingency, year 2000) + ~7000 person years
5-May-05SLAC17 RF SC Linac Challenges Energy: 500 GeV, upgradeable to 1000 GeV RF Accelerating Structures –Accelerating structures must support the desired gradient in an operational setting and there must be a cost effective means of fabrication. –~17,000 accelerating cavities/500 GeV –Current performance goal is 35 MV/m, (operating at 30 MV/m ) Trade-off cost and technical risk. 1 m Risk Cost~Theoretical Max
5-May-05SLAC18 (Improve surface quality -- pioneering work done at KEK) BCPEP Several single cell cavities at g > 40 MV/m 4 nine-cell cavities at ~35 MV/m, one at 40 MV/m Theoretical Limit 50 MV/m Electro-polishing
5-May-05SLAC19 Gradient Results from KEK-DESY collaboration must reduce spread (need more statistics) single-cell measurements (in nine-cell cavities)
5-May-05SLAC20 New Cavity Shape for Higher Gradient? TESLA Cavity A new cavity shape with a small Hp/Eacc ratio around 35Oe/(MV/m) must be designed. - Hp is a surface peak magnetic field and Eacc is the electric field gradient on the beam axis. - For such a low field ratio, the volume occupied by magnetic field in the cell must be increased and the magnetic density must be reduced. - This generally means a smaller bore radius. - There are trade-offs (eg. Electropolishing, weak cell-to-cell coupling, etc) Alternate Shapes
5-May-05SLAC21 Gradient vs Length Higher gradient gives shorter linac –cheaper tunnel / civil engineering –less cavities –(but still need same # klystrons) Higher gradient needs more refrigeration –‘cryo-power’ per unit length scales as G 2 /Q 0 –cost of cryoplants goes up!
5-May-05SLAC22 Klystron Development THALUS CPI TOSHIBA 10MW 1.4ms Multibeam Klystrons ~650 for 500 GeV +650 for 1 TeV upgrade
5-May-05SLAC23 Towards the ILC Baseline Design Not cost drivers But can be L performance bottlenecks Many challenges!
5-May-05SLAC24 Parameters of Positron Sources rep rate # of bunches per pulse # of positrons per bunch # of positrons per pulse TESLA TDR5 Hz28202 · · NLC120 Hz · · SLC120 Hz15 · DESY positron source 50 Hz11.5 · 10 9
5-May-05SLAC25 Positron Source Large amount of charge to produce Three concepts: –undulator-based (TESLA TDR baseline) –‘conventional’ –laser Compton based
5-May-05SLAC26
5-May-05SLAC27
5-May-05SLAC28
5-May-05SLAC29 Strawman Final Focus
5-May-05SLAC30 International/Regional Organization ILC-Americas Regional Team Regional Director and Deputy Institutional ILC Managers for major instiutional members Cornell ILC-NSF PI TRIUMF ILC-Canada Manager NSF-funded Institutions Canadian Institutions Lead Labs Work Package Oversight ILCSC GDE - Director Regional USLCSG Funding Agencies FNAL ILC-FNAL Manager WP 1.FNAL WP 1.ANL WP 3.FNAL SLAC ILC-SLAC Manager WP 2.SLAC WP 2.BNL WP 3.SLAC communications ILC-AsiaILC-Europe International Regional
5-May-05SLAC31 Fall 2002: ICFA created the International Linear Collider Steering Committee (ILCSC) to guide the process for building a Linear Collider. Asia, Europe and North America each formed their own regional Steering Groups (Jonathan Dorfan chairs the North America steering group). Physics and Detectors Subcommittee (AKA WWS) Jim Brau, David Miller, Hitoshi Yamamoto, co-chairs (est by ICFA as free standing group) International Linear Collider Steering Committee Maury Tigner, chair Parameters Subcommittee Rolf Heuer, chair (finished) Accelerator Subcommittee Greg Loew, chair Comunications and Outreach Neil Calder et al Technology Recommendation Panel Barry Barish, chair (finished) Global Design Initiative organization Satoshi Ozaki, chair (finished) GDI central team site evaluation Ralph Eichler, chair GDI central team director search committee Paul Grannis, chair
5-May-05SLAC32 Attendees: Son (Korea); Yamauchi (Japan); Koepke (Germany); Aymar (CERN); Iarocci (CERN Council); Ogawa (Japan); Kim (Korea); Turner (NSF - US); Trischuk (Canada); Halliday (PPARC); Staffin (DoE – US); Gurtu (India) Guests: Barish (ITRP); Witherell (Fermilab Director,) “ The Funding Agencies praise the clear choice by ICFA. This recommendation will lead to focusing of the global R&D effort for the linear collider and the Funding Agencies look forward to assisting in this process. The Funding Agencies see this recommendation to use superconducting rf technology as a critical step in moving forward to the design of a linear collider.” FALC is setting up a working group to keep a close liaison with the Global Design Initiative with regard to funding resources. The cooperative engagement of the Funding Agencies on organization, technology choice, timetable is a very strong signal and encouragement. Working with Funding Agency (FALC)
5-May-05SLAC33 GDE – Near Term Plan Organize the ILC effort globally –Undertake making a “global design” over the next few years for a machine that can be jointly implemented internationally. Snowmass Aug Begin to define Configuration (1 st Step) GDE Dec Baseline Configuration document by end of 2005 Put Baseline under Configuration Control Conceptual Design of Baseline by end of 2006 –Include site dependence – 3 or more sample sites –Detector Design Concept / Scope (1 vs 2, options, etc) –Reliable Costs -- emphasis during design on cost consciousness --- value Engineering, trade studies, industrialization, etc –Coordinate worldwide R & D efforts, in order to demonstrate and improve the performance, reduce the costs, attain the required reliability, etc. (Proposal Driven to GDE)