Post on 25-Aug-2021
Prospect of Ingot Nb Cavities for
International Linear Collider (ILC)
Akira Yamamoto (KEK/CERN) for the
Linear Collider Collaboration (LCC)
To be presented at ADS-2014, Richmond, 15 Oct., 2014 1
Outline • Introduction
• Progress in SRF Accelerator R&D and Design
• Toward Realization
• Summary
2014/08/26, A. Yamamoto ILC 2
d ν
Atom： ４E5 yrs
Proton, 1E-4 sec
Star 10E8 yrs
Nucleus 3 min.
Elementary Particles
Study of Universe/Cosmos
Hist
ory
of t
he U
nive
rse
~ 300 k Years - Limit of optical astronomical
observation Earlier Period - Elementary particle physics taking a major role, Very early universe Time range: 10-10 – 10-34 seconds being investigated by using particle accelerators
A. Yamamoto, 2014/10/15 3
Becoming inevitable fundamental technology
Applied Superconductivy Particle Acceleratoes
SC magnet technology
Electron Acc.
SRF technology
LHC
Proton Acc.
ILC
A. Yamamoto, 2014/10/15 4
Circular Accelerators to Linear Accelerators for Energy Frontier e+-e- Colliders
A. Yamamoto, 13/04/17 ILC Accelerator 5
SC Magnet
２T、limit
Proton
Electron
SC Cavity
ILC
For overcoming Synchroton Radiation
ILC Technical Design Phase
A. Yamamoto, 2014/10/15 6
ILC-GDE
2005 2006 2007 2008 2012 2009 2010 2011 2013
Tech. Design：TDP1
Higgs discovered
126 GeV
Selection of SC Technology
TDP 2
Ref. Design (RDR) LCC
LHC
2004
TDR
1980’ ~ Basic Study
2013.6.12 2012.12.15
TDR completion
2014
ILC TDR Layout
2014/08/26, A. Yamamoto
Damping Rings Polarised electron source
E+ source
Ring to Main Linac (RTML) (including bunch compressors)
e- Main Linac
e+ Main Linac
Parameters Value
C.M. Energy 500 GeV
Peak luminosity 1.8 x1034 cm-2s-1
Beam Rep. rate 5 Hz
Pulse duration 0.73 ms
Average current 5.8 mA (in pulse)
E gradient in SCRF acc. cavity
31.5 MV/m +/-20% Q0 = 1E10
ILC 7
Higgs Boson?
Z Z boson
W W boson
γ photon
g gluon
ν τ τ-neutrino
τ tau
b bottom
t top
ν µ µ-neutrino
µ muon
s strange
c charm
νe
e-neutrino
e electron
d down
up u
Lept
ons
Qua
rks
© Brian Foster
Particles and
Forces
Discovered at LHC Precise study by ILC
A full set of Fundamental Particles
A. Yamamoto, 2014/10/15 8
Outline • Introduction
• Progress in SRF Accelerator R&D and Design
• Toward Realization
• Summary
2014/08/26, A. Yamamoto ILC 9
main linacbunchcompressor
dampingring
source
pre-accelerator
collimation
final focus
IP
extraction& dump
KeV
few GeV
few GeVfew GeV
250-500 GeV
ILC Accelerator Concept
SRF Technology
Nano-beam Technology
- Electron and Positron Sources (e-, e+) : - Damping Ring (DR): - Ring to ML beam transport (RTML）: - Main Linac (ML）：SCRF Technology - Beam Delivery System (BDS） 2014/08/26, A. Yamamoto ILC 10
Technical Highlight in TD Phase and beyond
• SCRF Technology – Cavity: High Gradient R&D (EU, Ams, AS) :
• 35 MV/m with 50% yield by 2010 , and 90% by 2012 (TDR) • Manufacturing with cost effective design
– Cryomodule performance (EU, Ams, AS) – Beam Acceleration
• 9 mA: FLASH (DESY) • 1 ms: STF2 (KEK)- Quantum Beam
– E-XFEL construction in progress (beyond TDR) – LCLS at SLAC to be constructed
• Nano-beam handling – ILC-like beam acceleration
• Ultra-low beam emittance: Cesr-TA, ATF • Ultra-small beam size at Final Focusing, 44 nm: ATF2
2014/08/26, A. Yamamoto ILC 11
Technical Highlight in TD Phase and beyond
• SCRF Technology – Cavity: High Gradient R&D (EU, Ams, AS) :
• 35 MV/m with 50% yield by 2010 , and 90% by 2012 (TDR) • Manufacturing with cost effective design
– Cryomodule performance (EU, Ams, AS) – Beam Acceleration
• 9 mA: FLASH (DESY) • 1 ms: STF2 (KEK)- Quantum Beam
– E-XFEL construction in progress (beyond TDR) – LCLS at SLAC to be constructed
• Nano-beam handling – ILC-like beam acceleration
• Ultra-low beam emittance: Cesr-TA, ATF • Ultra-small beam size at Final Focusing, 44 nm: ATF2
2014/08/26, A. Yamamoto ILC 12
Björn Wiik vision
Under construction
Under construction
TDR by 2012
R&D needed
ITRP Recommendation
Progress and Prospect in SRF Cavity Gradient
2014/08/26, A. Yamamoto ILC 13
Björn Wiik vision
Under construction
Under construction
TDR by 2012
R&D needed
ITRP Recommendation
Progress and Prospect in SRF Cavity Gradient
14 JLab and DESY leading the SRF technology and the accelerator applications
Progress in 1.3 GHz 9-cell Cavity Production
2014/08/26, A. Yamamoto
year Capable Lab. Capable Industry 2006 1
DESY 2
ACCEL, ZANON 2011 4
DESY, JLAB, FNAL, KEK 4
RI, ZANON, AES, MHI,
2012 5 DESY, JLAB, FNAL, KEK, Cornell
5 RI, ZANON, AES, MHI, Hitachi
ILC
- One Lab (2 vendor) in 2006, and - 5 Lab (5 vendor) in 2012 may handle it
15
SCRF Linac Technology
1.3 GHz Nb 9-cellCavities 16,024
Cryomodules 1,855
SC quadrupole pkg 673
10 MW MB Klystrons & modulators 436 *
Approximately 20 years of R&D worldwide Mature technology, overall design and cost
* site dependent
2014/08/26, A. Yamamoto 16 ILC
2014/08/26, A. Yamamoto ILC
IPAC14: Courtesy: H. Weise
E-XFEL: under construction 800 Cavities under production (at RI, Zanon) , and assembled / Tested at CEA-Saclay, DESY
17
SC Linac (~ 1 km)
SCRF Cavity Production
2014/08/26, A. Yamamoto ILC
IPAC14: Courtesy: H. Weise
2014.6: # cavities produced > 300. Usable Gradient: ~ < 30 > MV/m
18
2011 disassemble S1-Global, start construction of STF accelerator(Injector + QB) 2012 Feb: QB accelerator commissioning Apr: beam acceleration Jun: beam focus for Laser-Compton Jul to Mar: experiment of Laser-Compton (QB) 2013 Apr: disassemble Laser-Compton start installation of CM-1 Sep: two set of 4-cavity train completed Oct: Cryomodule assembly in STF tunnel Dec: CM-1 completed 2014 Apr: start CM-2a assembly Jul: CM-1 and CM-2a connection will be completed Oct: Cool-down test
19
CM-1
STF Accelerator
CM-2a
CM-1
CM-2a
Will it work ? System Tests - KEK
90 % yield for 31/5 MV/m
2014/08/26, A. Yamamoto ILC
SCRF Main Linac Parameters, Demonstrated Characteristics Parameter Unit Demonstrated
Average accelerating gradient 31.5 (±20%) MV/m DESY, FNAL, JLab, Cornell, KEK,
Cavity Q0 1010
(Cavity qualification gradient 35 (±20%) MV/m)
Beam current 5.8 mA DESY-FLASH, KEK-STF
Number of bunches per pulse 1312
Charge per bunch 3.2 nC
Bunch spacing 554 ns
Beam pulse length 730 ms DESY-FLASH, KEK-STF
RF pulse length (incl. fill time) 1.65 ms DESY-FLASH, KEK-STF, FNAL-ASTA
Efficiency (RFbeam) 0.44
Pulse repetition rate 5 Hz
Peak beam power per cavity 190* kW * at 31.5 MV/m 20 2014/08/26, A. Yamamoto ILC
ILC Candidate Location: Kitakami Area
Oshu
Ichinoseki
Ofunato
Kesen-numa
A. Yamamoto, 2014/10/15 21
Sendai
Express- Rail
High-way
IP Region
TDR handed to LCC Director Lyn Evans
U. Tokyo
CERN
Fermilab
ILC TDR published in a Worldwide Event: Tokyo Geneva Chicago
2014/08/26, A. Yamamoto ILC 22
Outline • Introduction
• Accelerator R&D and Baseline Design
• Toward Realization
• Summary
2014/08/26, A. Yamamoto ILC 23
ILC in Linear Collider Collaboration ICFA
Chair: N. Lockyer
Program Adv. Committee PAC – Chair: N. Holtkamp
FALC Chair: Y. Okada
Physics & Detectors – H. Yamamoto
CLIC – S. Stapnes
Linear Collider Board LCB – Chair: S. Komamiya
ILC – M. Harrison
Tech. Board
Linear Collider Collab. LCC Directorate
- Director: L. Evans
Deputy (Physics) – H. Murayama
Regional Directors - B. Foster (EU) - H. Weerts (AMs) - A. Yamamoto (AS)
KEK LC Project Office
KEK
ILC 2014/08/26, A. Yamamoto 24
ILC Time Line: Progress and Prospect
A. Yamamoto, 2014/05/12
Expecting ~ (2+ 4) year Being re-studied
25
Preparation Phase
We are here, 2014 AWLC14
SCRF Procurement/Manufacturing Model
Regional hub-laboratories responsible to regional procurements to be open for any world-wide industry participation
Regional Hub-Lab: E, & …
Regional Hub-Lab:
A
Regional Hub-Lab:
B
Regional Hub-Lab:
D
World-wide Industry responsible to
‘Build-to-Print’ manufacturing
ILC Host-Lab
Regional Hub-Lab: C: responsible to
Hosting System Test and Gradient Performance
Technical Coordination for Lab-Consortium
: Technical coordination link : Procurement link
A. Yamamoto, 2014/10/15 26
Cavity/Cryomodule Fabrication
A. Yamamoto, 2014/10/15 27
Purchasing Material/Sub-component
Manufacturing Cavity：
Processing Surface
Assembling LHe-Tank ：
Qualifying Cavity, 100 %：
Cryomodule Assembly:: CM 組立
Cavity String Assembly：
Qualifying CMs, 33 + 5 %：
Short End group HOM1
× ８
12 EBW place
Long End group
Dumbbell x8
End cell : long side
End cell : short side
HOM2 pickup port beam pipe
beam pipe input port
center cell x8
Cavity Fabrication (TESLA Cavity)
A. Yamamoto, 2014/10/15 28
56 parts: - Nb = 46, Nb-Ti = 10, by using press, de-burring, machining 75 Electron Beam Welding (EBW) :
SCRF Fabrication Process at KEK
29
High Pressure Code Applied
A. Yamamoto, 2014/10/15
Process steps - fine grain Niobium
During this process foreign materials can be embedded so QA is required
A. Yamamoto, 2014/10/15 30
Courtesy: G. Myneni
A New High Resolution, Optical Inspection System
camera
white LED half mirror
EL EL
mirror
motor & gear for mirror
camera & lens
sliding mechanism of camera
tilted sheet illumination by Electro-Luminescence
perpendicular illumination by LED & half mirror
Camera system (7µm/pix) in 50mm diameter pipe.
For visual inspection of cavity inner surface.
~600µm beads on Nb cavity
31
Iwashita (Kyoto) and Hayano (KEK) et al.
DESYand FNAL also using this system in cooperation with KEK
A. Yamamoto, 2014/10/15
Progress in SCRF Cavity Gradient in ILC Technical Design Phase
2014/08/26, A. Yamamoto
Production yield: 94 % at > 35+/-20% Average gradient: 37.1 MV/m > R&D goal of 35 MV/m reached (2012)
ILC 32
A Direction to be Investigated for the Nb disk Mass-production
Clean surface from the beginning of Nb sheets Direct slicing from Nb Ingot (having high purity)
Proposed and patentend in the US, by G. Myneni, P. Kneisel (Jlab) and T. Carneiro (CBMM)
(Patented in Japan and in Europe, by KEK, Tokyo-Denkai, and others)
Keep clean surface w/ directly sliced Nb-sheets w/o additional rolling causing contamination and defects
On the other hand, necessary mechanical uniformity and stability for press-work
with tighter tolerance in assembly.
33 A. Yamamoto, 2014/10/15
A Direction to be Investigated for the Nb disk Mass-production
Clean surface from the beginning of Nb sheets Direct slicing from Nb Ingot (having high purity)
Proposed and patentend in the US, by G. Myneni, P. Kneisel (Jlab) and T. Carneiro (CBMM)
(Patented in Japan and in Europe, by KEK, Tokyo-Denkai, and others)
Keep clean surface w/ directly sliced Nb-sheets w/o additional rolling causing contamination and defects
On the other hand, necessary mechanical uniformity and stability for press-work
with tighter tolerance in assembly.
34 A. Yamamoto, 2014/10/15
A Direction to be Investigated for the Nb disk Mass-production
Clean surface from the beginning of Nb sheets Direct slicing from Nb Ingot (having high purity)
Proposed and patentend in the US, by G. Myneni, P. Kneisel (Jlab) and T. Carneiro (CBMM)
(Patented in Japan and in Europe, by KEK, Tokyo-Denkai, and others)
Keep clean surface w/ directly sliced Nb-sheets w/o additional rolling causing contamination and defects
On the other hand, necessary mechanical uniformity and stability for press-work
with tighter tolerance in assembly.
35 A. Yamamoto, 2014/10/15
Technical Specification Example for Nb Sheet
Electrical Properties RRR: > 300
Chemical contents see table
Microstructure Re-crystalized 100 % Grain-size: ASTM 6 or finer Local grain size: ASTM 4-5
Mechanical Properties Ultimate strength: > 140 N/mm2, RT Yield strength: TBD (> xx N/mm2, RT) Elogation; > 30 % Hardness: ≤ 60
Shape/size: TBD Rect. Sheet : ~ 300 mm sq. or Circular sheet: ~280 mm dia. with a center-hole
Possibility of Blanking (in consortium: to be discussed) Thickness : 2.8 mm +/- 0.1 mm Flatness: 2 % or better Surface roughness: < 15 µm (RF side)
A. Yamamoto, 2014/10/15 36
Technical Specification Example for Nb Sheet
Electrical Properties RRR: > 300
Chemical contents see table
Microstructure Re-crystalized 100 % Grain-size: ASTM 6 or finer to be updated to ~ 1 cm Local grain size: ASTM 4-5 to be updated
Mechanical Properties Ultimate strength: > 140 N/mm2, RT Yield strength: TBD (> 40 ~ 50 N/mm2, RT) Elogation; > 30 % Hardness: ≤ 60
Shape/size: TBD Rect. Sheet : ~ 300 mm sq. or Circular sheet: ~280 mm dia. with a center-hole
Possibility of Blanking (in consortium: to be discussed) Thickness : 2.8 mm +/- 0.1 mm Flatness: 2 % or better Surface roughness: < 15 µm (RF side)
A. Yamamoto, 2014/10/15 37
Personal comment: - Ta, fraction can be more relaxed. - However Fe fraction should be well kept very low.
Nb Sheet directly cut out anticipated with medium grain size
RRR: ~ 200 with well controlled impurities with a level of < 10 ppm.
Grain size : ~ 1 cm (a few cm also acceptable) To be optimized for press-work,
Size: > 260 mm Thickness: ~ 2.8 mm Cleanness:
Min. surface work No rolling !!
38 A. Yamamoto, 2014/10/15
An R&D work in progress w/CBMM/JLab-KEK Collaboration
Motivation and Progress: Comparing sliced Nb sheets with rolled Nb sheets Fabricating a single-cell cavity and Performing RF test,
Fine-grain, rolled, high RRR (300) : sample from TD Large-grain, sliced, high RRR (300) : sample from TD Large-grain, sliced, lower RRR (TBD) : sample from CBMM
We need to evaluate RRR of this sample, and KEK is planning to do
Future plan to be added: Medium-grain, sliced, lower RRR
39 A. Yamamoto, 2014/10/15
A Slice from a Medium Grain Ingot
A. Yamamoto, 2014/10/15 40
Courtesy: CBMM
Ingot Nb with additive of Zr (~ 0.1 %)
CBMM Ingot received and preparation in progress at KEK
41 A. Yamamoto, 2014/10/15
R&D Plan for LG, lower RRR ingot (CBMM)
Slicing: by August, 2014
Fabrication: by December, 2014 Including Nb sample RRR measurement
Evaluation: in (early) 2015
Sincere thanks to CBMM proving the sample ingot, and to Dr. G. Myneni for this cooperation established
42 A. Yamamoto, 2014/10/15
RRR Measurement Set-up at KEK He gas to/from Compressor
Signals
Vac. pumping
Radiation shield Sample Plat-form
Compressor Pump
G10 plate (150×100×1mm) Nb Samples to be (120×4×1mm)
T-sensor
Process of Nb sheet from ingot
KEK, Masashi YAMANAKA 44
After wire-slicing After mechanical polishing After chemical polishing
Polishing machine Multi-wire saw
Key Issues to be figured out Fabrication of Nb sheets
Size: 260 mm diameter, ~ 3 mm thick Quantity: ~ 18,000 x 20 = 360,000 disks (~1.2 kg/disk) Purity, Residual Resistance Ratio
RRR ~ 200 with control of impurity to be investigated (currently > 300 )
Mechanical uniformity Grain-size : to be optimized How it can be expected with industrial process?
Best solution expected Nb Ingot with medium grain-size to be optimized
45 A. Yamamoto, 2014/10/15
Summary ILC has reached the TDR completed, and been in an
official process,by Japanese Government, for “Science justification” and “TDR validation”.
SRF cavity fabrication (industrialization) process needs to be optimized with the best cost effective approach,
Ingot Nb with a medum grain-size would be one of very logical and practical approaches, anticipated.
A. Yamamoto, 2014/10/15 46
Acknowledgments
I would thank Dr. G Myneni for his kindest guidance and leading me to realize this opportunity.
I would thank Mr. R. Ribas and CBMM, for the kindest cooperation to provide a sample ingot and for the fruitful discussions during our visiting CBMM..
47 A. Yamamoto, 2014/10/15