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ILC Accelerator Activities in North America (cooperation with France ). Presentation at IRFU Linear Collider Days prepared by: Marc Ross ( SLAC ) November 29, 2013. Completing the ILC Technical Design Phase. January 2013. TDP Goals: - PowerPoint PPT Presentation
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12013 IRFU Linear Collider Days
ILC Accelerator Activities in North America(cooperation with France)
Presentation at IRFU Linear Collider Days prepared by:
Marc Ross (SLAC)
November 29, 2013
22013 IRFU Linear Collider Days
TDP Goals:» R & D to enable Project Proposal and updated Value estimate –
with Cost Containment» SC RF Technology Transfer
• development of a strong industrial base Technical Design Report:
» Consists of two parts: 1) R & D Report and 2) Design Description Beam Test Facilities:
» SRF Linac: Fermilab NML, DESY E-XFEL and FLASH, KEK STF » Beam Dynamics: Cornell CesrTA (2008 – 2010)» Beam Tuning: KEK ATF2
Production / Industrialization:» CEBAF Upgrade and E-XFEL
Completing the ILC Technical Design Phase
January 2013
32013 IRFU Linear Collider Days
Completing the TDP: Outline TDP Goals:
» R & D to enable Project Proposal and updated Value estimate – with Cost Containment
» SC RF Technology Transfer • development of a strong industrial base
Technical Design Report:» Consists of two parts: 1) R & D Report and 2) Design Description
Beam Test Facilities:» SRF Linac: Fermilab NML, DESY E-XFEL and FLASH, KEK STF » Beam Dynamics: Cornell CesrTA (2008 – 2010)» Beam Tuning: KEK ATF2
Production / Industrialization:» CEBAF Upgrade and E-XFEL
Present
42013 IRFU Linear Collider Days
SC RF Technology Transfer » Development of a strong industrial base
Production / Industrialization:» CEBAF Upgrade and E-XFEL
Beam Test Facilities:» SRF Linac: Fermilab NML, DESY E-XFEL and FLASH, KEK STF » Beam Dynamics: Cornell CesrTA (2008 – 2010)» Beam Tuning: KEK ATF2
US contribution to ‘Linear Collider Collaboration’ (LCC) ‘P5’ prioritization activity
ILC Accelerator Activities: OutlineBy the end of the XFEL Production > 1000 cavities will have been fabricated by industry and processed using the basic TESLA – recipe.
52013 IRFU Linear Collider Days
Cavity production lines fully functioning: 8 cavities / week» Two companies
Cryomodule production:• Three pre-series CM (XM-3, XM-2, XM-1) in process; typical
time to construct 4 months; time to test unknown • Production series of 81 each started Sep. 02, 2013; • One CM / week nominal; one production line (CEA-Saclay)
24 cavities to be used for high – gradient development» (See E. Elsen)
EU - XFEL
6'BB Lunch', M. Ross (SLAC)
Jefferson Lab CEBAF 12 GeV Upgrade
7'BB Lunch', M. Ross (SLAC)
8'BB Lunch', M. Ross (SLAC)
Slide dated late 09.2013All C100 cryomodules are now installed (11.2013)
9'BB Lunch', M. Ross (SLAC)
102013 IRFU Linear Collider Days
Following BESAC (Basic Energy Sciences Advisory) report in late July 2013:» Shakeup of US accelerator construction projects:» SLAC LCLS-II project redefined» ANL APS upgrade program redefined
SLAC Proposal:» 4 GeV CW SRF Linac-based FEL» Use ILC / XFEL 1.3 GHz technology» Installed in the upstream 1/3 of the SLAC linac housing» (50 year old S-band linac to be completely removed)» First light end of FY 2019
SLAC Proposal:
11
SLAC Director Chi-Chang Kao, 27 September 2013:
12
Chi-Chang Kao, 27 September 2013:
13
LCLS-II and ILC
Much LCLS-II construction will be done at Fermilab, using infrastructure intended for ILC
18 CM? (50%)Other CM to be made at JLab (and Cornell)
Saclay CM assembly industrial experience unique
US team have made ~ two ILC CM. LCLS-II effort will help understand US-domestic technical, cost, and industrialization
14
RF Parameters:
2013 IRFU Linear Collider Days
15
RF Parameters (2)
2013 IRFU Linear Collider Days
LCLS-II - Linac and Compressor Layout for 4 GeV
CM01 CM2,3 CM04 CM15 CM16 CM35BC1
270 MeVR56 = -65 mm
Ipk = 60 ALb = 0.40 mmsd = 1.4 %
BC21550 MeV
R56 = -65 mmIpk = 1000 A
Lb = 0.024 mmsd = 0.50 %
GUN0.75 MeV
LH98 MeV
R56 = -5 mmIpk = 12 A
Lb = 2.0 mmsd = 0.006 %
L0j 0
V0 97 MV
L1j =-26°
V0 =235 MV
HLj =-170°
V0 =40 MV
L2j = -28°
V0 = 1448 MV
L3j = 0
V0 = 2460 MV
LTU4.0 GeVR56 = 0
Ipk = 1000 ALb = 0.024 mmsd 0.02 %
100 pC; Machine layout 26SEP2013; Bunch length Lb is FWHM
3.9GHz
Linac V(MV)
j(deg)
Acc. Grad.
(MV/m)
No. Cryo Mod’s
No. Cav’s
Spare Cav’s
Cavities per
Amplifier
L0 97 * 14.6 1 8 1 1
L1 235 -26 15.1 2 16 1 ?
HL -40 -170 - 3 (3.9GHz) 12 0 12?
L2 1448 -28 15.5 12 96 6 32?
L3 2460 0 15.7 20 160 10 32?
* L0 phases: (-40, -52, 0, 0, 0, 13, 33), with cav-2 at 20% of other L0 cav’s.
Includes 2-km RW wake
2013 IRFU Linear Collider Days 16
17
First 800 m of SLAC linac (1964):
350 m
Marc Ross, SLAC LCLS-IISeptember 6, 2013
18
ILC R & D initiative: Power Coupler development
Mandated by PAC (12.2012) technical reviewCommon activity with Orsay /LAL
Issues:• Cost• Copper coating / flaking• Complex Assembly • Plug-compatibility
TTF3/XFEL coupler
STF-2 coupler
TDR coupler
(1) Deep Technical Review of Input Couplers
ILC specification• Power requirements
– We recommend to match the coupler to 30 MV/m for reduced filling time and smaller Qext range– Max coupler power at operation 450 kW (for 8.8 mA, 10Hz, Eacc=31.5 MV/m ±20%)– RF processing to at least four times max input power ~ 1.8 MW up to 500 us at test stand TW– Surface field not a problem for both designs, i.e. 40mm and 60mm are both ok– Should check flattop regulation at 25 MV/m and Qext ~ 1e7 (LFD)– TW testing on test stand up to 1.8MW has to be done for both: TTF3 and STF2
• Q-ext– Variable coupling is needed, remote operation– QL tuning range: 2-7x106 is needed, but we recommend 1-10 x 106
– 1-10 10∙ 6 is achieved with TTF3– STF2 has to be improved
• Antenna alignment:– Design should be +-2mm– For TTF3 coupler the most sensitive parameter is a horizontal antenna shift/tilt. 3mm shift change
QL by ~20%. Vertical tolerances are relaxed.– For STF-2 coupler this is not issue, mechanical design guarantee small shift.– TTF3 has to be improved
• Cryogenic loss:– Coupler contribution to cryogenic losses at 2K is ~5%. = not critical. – Major contribution from coupler is 70K
• Conditioning time– Both designs are ok– The nominal conditioning time of < 50h is achieved/demonstrated.
• Multipacting– DESY and SLAC simulations, tests and operation show no problem with TTF3– STF2 will be simulated, tests show no problem
• One vs. two windows– Many single window coupler are successful under operation– The single window would need to seal-off the cavity before the cavity-string installation into the
cryomodule. – Single window coupler for ILC would need complete new development and test program of
coupler (and module)– But it could be a significant cost saving
• Compatibility– Cavity and attached parts (power coupler, tuner, HOM coupler, feedthroughs, He vessel, thermal
connections, magnetic shield…) are tuned/balanced, it is not easy to exchange only parts of this composition
– STF2 coupler design does not fit in the compatibility requirements of the TDR (40mm cavity coupler flange)
• Cost– CPI: STF2 price is 1.9 higher– Toshiba: STF2 slightly lower price– RI: about same price– Industrial study of STF2 for design optimization and cost reduction is recommended– The TTF3 coupler mass fabrication has to be investigated
Recommendation:• STF2 coupler has to demonstrate stable long time (>6 month) beam operation in a
CM (TTF3 coupler has a long history in FLASH)• The ILC management recommend an adapted STF2 design with 40mm cavity flange.
In this case more development steps have to follow in order to realize the compatible design. The new design has to be proven with beam operation.
• The concept of plug compatibility has to be further developed in view of a spare part concept. We recommend spare modules, not individual parts.
• An industrial study of mass production for both designs is recommended• Industrial study of STF2 for design optimization and cost reduction is recommended.
ATF2 Program Status
Glen White, SLACJanuary 2013
2013 IRFU Linear Collider Days 23
Detector measures signal Modulation Depth “M”
N +
N -
[rad]
[rad]
2013 IRFU Linear Collider Days
measurable range determined by fringe pitch
depend on crossing angle θ (and λ )
N: no. of Compton photonsConvolution between e- beam profile and fringe intensity
)2/sin(2
ykd
--
-
-
Md
kNNNN
y
yy
)cos(ln2
2
)(2exp)cos( 2
s
s
M
Focused Beam : large M
Dilluted Beam : small M
Small σy
Large σy
13/05/29 24
Crossing angle θ
174° 30° 8° 2°
Fringe pitch 266 nm 1.03 μm 3.81 μm 15.2 μm
Lower limit 20 nm 80 nm 350 nm 1.2 μm
Upper limit 110 nm 400 nm 1.4 μm 6 μm
)2/sin(2
ykd
Md
y
)cos(ln2
2
s
Measures σy* = 20 nm 〜 few μm with < 10% resolution
Expected Performance
select appropriate mode according to beam focusing
2013 IRFU Linear Collider Days
σy and M for each θ mode
13/05/29 25
174 deg. 30 deg.
2 - 8 deg
Crossing angle continuously adjustable by prism 13/05/29
2013 IRFU Linear Collider Days26
Vertical table 1.7 (H) x 1.6 (V) m
• Interferometer• Phase control (piezo stage)
path for each θ mode ( auto-stages + mirror
actuators )
beam pipe
Laser transported to IP
optical delay
half mirror
transverse : laser wire scan
precise position alignment by remote control
2013 IRFU Linear Collider Days
Role of IPBSM in Beam Tuning
13/05/2927
beforehand …. Construct & confirm laser paths, timing alignment
Longitudinal : z scan
After all preparations ……….
continuously measure σy using fringe scans Feed back to multi-knob tuning
laser spot size σt,laser = 15 – 20 μm
12/20 : 1st success in M detection
at 174 deg mode
Beam time status in 2012
stable measurements of M 〜 0.55
Feb ; 30 deg mode commissioned ( 1st M detection on 2/17)
2013 IRFU Linear Collider Days
M = 0.52 ± 0.02 (stat) σy = 166.2 ± 6.7 (stat) [nm]
• 2 - 8 ° mode: clear contrast ( Mmeas ~ 0.9)• Prepared 174 deg mode commissioning
Suppress systematic errors Higher laser path stability / reliability
High M measured at 30 ° mode Contribute with stable operation to
ATF2 beam focusing / tuning study
(10 x bx*, 3 x by* optics)
Spring run
Major optics reform of 2012 summer
Winter runLast 2 days in Dec runMeasured many times M = 0.15 – 0.25 ( correspond to σy 〜 70 – 82 nm )
Large step towards achieving ATF2 ‘s goal !! error studies ongoing aimed at deriving “true beamsize”
preliminary
preliminary
* IPBSM systematic errors uncorrected** under low e beam intensity ( 〜 1E9 e / bunch)
10 x βx* , 1 x βy*
By IPBSM group@KEK
13/05/29 28
measured M over continuous reiteration of linear /nonlinear@ tuning knobs @ 174 ° mode
Beam time status in 2013 Spring
2013 IRFU Linear Collider Days
dedicated data for error studies under analysis
ex ) consecutive 10 fringe scans
preliminary
Time passed
measure M vs time after all conditions optimized
preliminary
Stable IPBSM performance major role in beam tuning
10 x bx*, 1 x by*
13/05/29
29
174 ° mode ”consistency scan”
moving towards goal of σy = 37 nm :higher IPBSM precision and stability & looser current limits of normal / skew sextupoles current
M 〜 0.306 ± 0.043 (RMS) correspond to σy 〜 65 nmBest record
from Okugi-san’s Fri operation meeting slides
The Reality… May 2 week Cont. Run
• Summary of all scans during 2 week ops period– Summary plot courtesy of Edu.
2013 IRFU Linear Collider Days 30
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