Transcript News from the ILC Barry Barish Users’ Meeting Fermilab 9-June-05 Why e+e- Collisions? • elementary particles • well-defined – energy, – angular momentum • uses full COM energy • produces.

News from the ILC
Barry Barish
Users’ Meeting
Fermilab
9-June-05
Why e+e- Collisions?
• elementary particles
• well-defined
– energy,
– angular momentum
• uses full COM energy
• produces particles
democratically
• can mostly fully
reconstruct events
9-June-05
Fermiab Users' Meeting - Barish
2
A Rich History as a Powerful Probe
9-June-05
Fermiab Users' Meeting - Barish
3
The Energy Frontier
9-June-05
Fermiab Users' Meeting - Barish
4
Why a TeV Scale?
• Two parallel developments over the past few
years (the science)
– The precision information e+e- and n data at present
energies have pointed to a low mass Higgs;
Understanding electroweak symmetry breaking,
whether supersymmetry or an alternative, will require
precision measurements.
– There are strong arguments for needing both pp and
e+e- collisions to fully exploit the exciting science
expected in the 1 TeV energy scale.
9-June-05
Fermiab Users' Meeting - Barish
5
Why a TeV Scale e+e- Accelerator?
• Two parallel developments over the past few
years (the technology)
– Designs and technology demonstrations have
matured on two technical approaches for an e+ecollider that are well matched to our present
understanding of the physics.
9-June-05
Fermiab Users' Meeting - Barish
6
Which Technology to Choose?
– Two alternate designs -- “warm” and “cold” had
come to the stage where the show stoppers had
been eliminated and the concepts were well
understood.
– A major step toward a new international machine
required uniting behind one technology, and then
working toward a unified global design based on
the recommended technology.
9-June-05
Fermiab Users' Meeting - Barish
7
International Technology Review Panel
9-June-05
Fermiab Users' Meeting - Barish
8
Evaluate a Criteria Matrix
• The panel analyzed the technology choice
through studying a matrix having six general
categories with specific items under each:
–
–
–
–
–
–
the scope and parameters specified by the ILCSC;
technical issues;
cost issues;
schedule issues;
physics operation issues;
and more general considerations that reflect the
impact of the LC on science, technology and society
9-June-05
Fermiab Users' Meeting - Barish
9
The Recommendation
• We recommend that the linear collider be based
on superconducting rf technology
– This recommendation is made with the understanding that we
are recommending a technology, not a design. We expect the
final design to be developed by a team drawn from the
combined warm and cold linear collider communities, taking full
advantage of the experience and expertise of both (from the
Executive Summary).
– The superconducting technology has several very nice features
for application to a linear collider. They follow in part from the
10
9-June-05
low rf frequency. Fermiab Users' Meeting - Barish
The Community then Self-Organized
Nov 13-15, 2004
9-June-05
Fermiab Users' Meeting - Barish
11
The First ILC Meeting at
KEK
9-June-05
Fermiab Users' Meeting - Barish
12
The Global Design Effort
Formal organization begun at LCWS 05 at Stanford
in March 2005 when I became director of the GDE
Technically Driven Schedule
GDE – Near Term Plan
• Staff the GDE
–
–
–
–
–
Administrative, Communications, Web staff
Regional Directors (each region)
Engineering/Costing Engineer (each region)
Civil Engineer (each region)
Key Experts for the GDE design staff from the world
community (please give input)
– Fill in missing skills (later)
Total staff size about 20 FTE (2005-2006)
9-June-05
Fermiab Users' Meeting - Barish
14
GDE – Near Term Plan
• Schedule
• Begin to define Configuration (Aug 05)
• Baseline Configuration Document by end of 2005
----------------------------------------------------------------------• Put Baseline under Configuration Control (Jan
06)
• Develop Reference Design Report by end of 2006
• Three volumes -- 1) Reference Design Report;
2) Shorter glossy version for non-experts and
policy makers ; 3) Detector Concept Report
9-June-05
Fermiab Users' Meeting - Barish
15
GDE – Near Term Plan
• Organize the ILC effort globally
– First Step --- Appoint Regional Directors within the
GDE who will serve as single points of contact for
each region to coordinate the program in that
region. (Gerry Dugan (North America), Fumihiko
Takasaki (Asia), offered to Brian Foster (Europe))
– Make Website, coordinate meetings, coordinate
R&D programs, etc
• R&D Program
– 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)
9-June-05
Fermiab Users' Meeting - Barish
16
Starting Point for the GDE
pre-accelerator
few GeV
source
KeV
damping
ring
few GeV
few GeV
bunch
compressor
9-June-05
250-500 GeV
main linac
extraction
& dump
final focus
IP
collimation
Superconducting
RF Main Linac
Fermiab Users' Meeting - Barish
17
Parameters for the ILC
• Ecm 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
9-June-05
Fermiab Users' Meeting - Barish
18
Towards the ILC Baseline Design
9-June-05
Fermiab Users' Meeting - Barish
19
Specific Machine Realizations
rf bands:
1.3
S-band (SLAC linac)
2.856 GHz
1.7 cm
C-band (JLC-C)
5.7
GHz
0.95 cm
X-band (NLC/GLC)
11.4 GHz
0.42 cm
25-30 GHz
0.2 cm
(CLIC)
GHz
l =
L-band (TESLA)
3.7 cm
Accelerating structure size is dictated by wavelength of the rf
accelerating wave. Wakefields related to structure size; thus so is
the difficulty in controlling emittance growth and final luminosity.
 Bunch spacing, train length related to rf frequency
 Damping ring design depends on bunch length, hence frequency
Frequency dictates many of the design issues for LC
9-June-05
Fermiab Users' Meeting - Barish
20
Cost Breakdown by Subsystem
cryo operations
4%
4%
instrumentation
2%
controls
4%
cf
31%
vacuum
4%
Civil
magnets
6%
installation&test
7%
systems_eng
8%
rf
12%
structures
18%
SCRF Linac
9-June-05
Fermiab Users' Meeting - Barish
21
TESLA Cavity
~1m
9-cell 1.3GHz Niobium Cavity
Reference design: has not been modified in 10 years
9-June-05
Fermiab Users' Meeting - Barish
22
What Gradient to Choose?
9-June-05
Fermiab Users' Meeting - Barish
23
single-cell measurements (in nine-cell cavities)
Gradient
Results from
KEK-DESY
collaboration
must reduce
spread (need
more statistics)
9-June-05
Fermiab Users' Meeting - Barish
24
Electro-polishing
(Improve surface quality -- pioneering work done at KEK)
BCP
EP
• 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
9-June-05
Fermiab Users' Meeting - Barish
25
How Costs Scale with Gradient?
2
Relative Cost
alin
G
$
 bcryo
G
Q0
35MV/m is
close to
optimum
Japanese
are still
pushing
for 4045MV/m
30 MV/m
would give
safety
margin
C. Adolphsen (SLAC)
9-June-05
Gradient MV/m
Fermiab Users' Meeting - Barish
26
Fermilab - Emerging ILC SCRF Program
H Carter
9-June-05
Fermiab Users' Meeting - Barish
27
Fermilab ILC SCRF Program
9-June-05
Fermiab Users' Meeting - Barish
28
Fermilab ILC SCRF Program
9-June-05
Fermiab Users' Meeting - Barish
29
Fermilab ILC SCRF Program
9-June-05
Fermiab Users' Meeting - Barish
30
Fermilab ILC SCRF Program
9-June-05
Fermiab Users' Meeting - Barish
31
Fermilab ILC SCRF Program
9-June-05
Fermiab Users' Meeting - Barish
32
TESLA Cavity
~1m
9-cell 1.3GHz Niobium Cavity
Reference design: has not been modified in 10 years
9-June-05
Fermiab Users' Meeting - Barish
33
Evolve the Cavities
Minor Enhancement
Low Loss Design
Modification to cavity shape
reduces peak B field. (A
small Hp/Eacc ratio around
35Oe/(MV/m) must be
designed).
This generally means a
smaller bore radius
Trade-offs (Electropolishing,
weak cell-to-cell coupling,
etc)
9-June-05
KEK currently producing prototypes
Fermiab Users' Meeting - Barish
34
New Cavity Design
Re-entrant
28 cell Super-structure
More radical concepts potentially offer
greater benefits.
But require time and major new
infrastructure to develop.
single-cell achieved
45.7 MV/m Q0 ~1010
(Cornell)
9-June-05
Fermiab Users' Meeting - Barish
35
ILC Siting and Civil Construction
• The design is intimately tied to the features of the
site
– 1 tunnels or 2 tunnels?
– Deep or shallow?
– Laser straight linac or follow earth’s curvature in
segments?
• GDE ILC Design will be done to samples sites in
the three regions
– North American sample site will be near Fermilab
9-June-05
Fermiab Users' Meeting - Barish
36
Fermilab ILC Civil Program
A Fermilab Civil Group is
collaborating with SLAC
Engineers and soon with
Japanese and European
engineers to develop methods
of analyzing the siting issues
and comparing sites.
The current effort is not
intended to select a potential
site, but rather to understand
from the beginning how the
features of sites will effect the
design, performance and cost
9-June-05
Fermiab Users' Meeting - Barish
37
Draft
27-May-05
Conventional Facilities Site Considerations
1
Site impacts on critical science parameters
1
Configuration (Physical Dimensions and
A
Layout)
5
Construction Cost Impacts (cont.)
5
Climate
C
.
.1
Usable Length and Width
Snowfall
1
.2
Flexibility for Adjustment of Alignment
.
Average
2
Ambient temperature
.
.a
Adaptable to Laser Straight
.b
Adaptable to Earth Curvature
Average
3
underground temperature
.
No
4 of days rainfall
5
.3
Depth of Tunnel
.4
Depth of Interaction Halls
.5
Accessibility to Tunnels
Environmental
D
Restrictions
5
Accessibility
E
5
Site
F Utility Support & Installation
1
5
Performance
B
(Vibration and Stability
Proximity
G
of Soil Borrow and Disposal Areas
5
.1
Natural Vibration/Noise Sources
Local
H
Labor
.
.a
9-June-05
Geologic Dynamic Properties
Construction
1
Rate Index
Fermiab Users' Meeting - Barish
38
Strawman Final Focus
9-June-05
Fermiab Users' Meeting - Barish
39
Fermilab and the ILC
• Fermilab is rapidly developing a superconducting RF
capability for the main linac design and development
for the ILC.
• The Civil group at Fermilab is playing a central role in
developing methods for understanding the siting and
the interplay with the design.
• Plans are being developed to build a strong
accelerator physics group at Fermilab for the ILC.
• There are many opportunities for involvement by the
experimental community in the accelerator, the
machine detector interfaces and the detector designs.
--------------------------------------------------------------------------------------
• Fermilab can position itself very well to be
able to succesfully bid to host the ILC, without
mortgaging the rest of the program
9-June-05
Fermiab Users' Meeting - Barish
40
Conclusions
Remarkable progress in the past two years toward
realizing an international linear collider:
important R&D on accelerator systems
definition of parameters for physics
choice of technology
start the global design effort
funding agencies are engaged
Many major hurdles remain before the ILC becomes a
reality (funding, site, international organization, detailed
design, …), but there is increasing momentum toward
the ultimate goal --- An International Linear Collider.
9-June-05
Fermiab Users' Meeting - Barish
41