1. LARP Role in Plans for HL-LHC Upgrades Giorgio Apollinari - US LARP Director USLUO, UW Madison – November 6th- 8th, 2013

2. Three Strong Reasons for LHC Upgrade
hypothetical luminosity
evolution
By continuous performance improvement and consolidation
By implementing HL-LHC
Almost a factor 3
J. Strait
1) after few years, statistical error hardly decreases
2) radiation damage limit of IR quadrupoles (~700 fb-1) reached by ~2020 =→ time for an upgrade!
3) extending physics potential!

3. Triplets Radiation Damage L. Bottura – RLIUP, Oct ’13
LTSW – FSU, November 2013

4. Context: Baseline LHC Upgrade Path
Time Line:
LS1*: “Nominal” ( )
Complete repairs of the superconducting joint and pressure relief problems which caused “the incident” in 2008 and currently limit the energy to 4+4 TeV.
“Lost memory” and retraining issues may limit the beam energy to somewhere between 6.5 and 7 TeV per beam.
At least 1x1034 cm-2s-1 peak luminosity
LS2: “Ultimate” (2017)
injector and collimation upgrades
At least 2x1034 cm-2s-1 peak luminosity
LS3: “HL-LHC” (~ )
Lower b* and compensate for crossing angle to maximize luminosity
5x1034 cm-2s-1 leveled luminosity
LARP lives in the context of LS3, with some “test deliverables” needed by LS2

5. LTSW – FSU, November 2013

6. HL-LHC Working Packages
Significant LARP and other US Involvement
LTSW – FSU, November 2013

7. LARP History & Evolution
The US LHC Accelerator Research Program (LARP) was formed in 2003 to coordinate US R&D related to the LHC accelerator and injector chain at Fermilab, Brookhaven, and Berkeley
SLAC joined shortly thereafter
Has also had some involvement with Jefferson Lab, Old Dominion University and UT Austin
LARP has contributed to the initial operation of the LHC, but much of the program is focused on future upgrades
The program is currently funded at a level of about $12-13M/year, divided among.
Magnet research (~half of program)
Accelerator research (Crab cavities, WBFS, Collimators, e-hollow lens,..)
Programmatic activities, including support for personnel at CERN
FY13-FY14 Evolution
Initial convergences on deliverables for HL-LHC
Program handled like a “project”

8. HL-LHC (main) magnet Needs
Type
Material
Field/Gradient
(T)/(T/m)
Aperture
(mm)
Length
(m)
Q1,Q3 Q2
Single aperture
Nb3Sn
(12.1) 140
150 8
6.7 D1
Nb-Ti
5.2 D2
Twin aperture
3.5…5.0
95…105
7…10 Q4
(5.9) 90
120
4.2
DS 11T
10.8 60 11
Correctors and other (resistive) magnets not listed

9. A matter of conductors !
HTS
20+ T
16T
10 T

10. US in-kind Contribution to HL-LHC: a preliminary look
Various Candidates:
150 mm aperture Nb3Sn quadrupoles
Crab Cavities
High Bandwidth Feedback System
Collimation and hallow e-beams
11 T Nb3Sn dipoles
Large Aperture NbTi D2 separator magnets
Process of convergence among CERN-DOE-U.S. Labs-LARP initiated in Dec ‘2012
Initial consensus on core Priorities:
Committed to a major stake in Nb3Sn quads
Crab cavities up to the SPS test and possibly beyond to production
High bandwidth feedback was seen as a high impact contribution for modest resources.
Back up options:
11 T dipoles
Proper “hand-off” if not continued in US
Hollow electron beams for halo removal
Support R&D into this effort in the event it’s chosen as a primary technology and circumstances allow its funding.
Low priority
There was not much interest in pursuing the D2 separators.
More than 75% of possible
US Contribution to HL-LHC

11. HL-LHC Nb3Sn Magnets IR Magnet
4 Q1 and 4 Q3 (2 per IR) plus 1 spare each from US
Q1 and Q3 will probably contain 2 ~4.5 m long magnets each, for a total of ~20 qudrupoles
4 Q2a and 4 Q2b from CERN
Option still open on the lenght of Q2.
E. Todesco

12. Ten years of intense R&D
Subscale Quad. SQ
0.3 m long
110 mm bore
SQ02
TQS01
LRS01
Technology Quadrupole
TQS - TQC
1 m long
90 mm bore
Long Racetrack LRS
3.6 m long
No bore
LQS01
LQS03
Long Quadrupole LQS
3.7 m long
90 mm bore
G > 170 T/m
Very Preliminary !
HQ01b-c
HQ01d-e
HQ02
High Field Quadrupole HQ
1 m long
120 mm bore
Summary graphics by courtesy of G. Sabbi and H. Felice (LBNL)

13. Long Magnets: LQS of LARP
3.3 m coils, 90 mm aperture
Goal: 200 T/m at 1.9 K
LQS01a: 202 T/m at 1.9 K
LQS01b: 222 T/m at 4.6 K
227 T/m at 1.9 K
LQS02: 198 T/m at 4.6 K 150 A/s
208 T/m at 1.9 K 150 A/s
limited by one coil
LQS03: 208 T/m at 4.6 K
210 T/m at 1.9 K
1st quench: 86% s.s. limit

14. S(L)QXF Models & QXF Production
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
Coil tooling
Model Coil fabrication (SQXF)
Support structure
Model Magnet Construction
Prototype tooling
Prototype construction (LQXF)
Series production
Installation
S(L)QXF Models
Short and Long QXF Models will require approximately 1.0 metric Ton of Nb3Sn in US ordered by FY15 (more at CERN)
Series Production
US scope: m long quads, i.e. 80 coils (UL=450m)
Unit Weigth ~ 100Kg/coil: total metric Tons of Nb3Sn. Considerable faction (~30-40%) needs to be available in cable format by early 2018
Assuming 18 months for strand delivery and ~few months for QC and cabling, a large order from US HL-LHC needs to be placed by late 2015/early 2016.

15. 11 T Development
This Ain’t LARP
At this time not a US in-kind contribution. Intellectually relevant as R&D program toward high field, accelerator quality, dipoles and a possible 100 km machine

16. Collimators and 11T Dipoles
This Ain’t LARP
Create space for additional collimators by replacing 8.33 T MB with 11 T Nb3Sn dipoles compatible with LHC lattice and main systems. kA
(in series with MB)
MB.B8R/L
11 T Nb3Sn
MB.B11R/L
15,66 m
LS2 : IR-2
4 MB => 8 x 5.5 m CM + spares
LS3 : IR-1,5 and Point-3,7
4 x 4 MB => 32 x 5.5 m CM + spares
5.5 m Nb3Sn
3 m Collim
5.5 m Nb3Sn
3 m Collim
Focus of joint R&D program aimed at Accelerator Quality Magnets between CERN and US. R&D program to be completed in US with conclusion of Short (1m) Models.

17. 11T Dipole R&D This Ain’t LARP Success ! Single aperture model
Twin aperture model
Second Nb3Sn Accelerator Quality Dipole (1m long) – Dec ‘12
Success !

18. Crab Cavities UK LARP Additional benefit Currently aiming for:
Without some compensation for crossing angle,
Reducing the b* will only increase luminosity by ~75% !
“Piwinski Angle”
Technical Challenges
Crab cavities have only barely been shown to work.
Never in hadron machines
LHC bunch length requires low frequency (400 MHz)
19.4 cm beam separation needs “compact” (exotic) design
Additional benefit
Crab cavities are an easy way to level luminosity!
Currently aiming for:
Down-select ~next year
SPS test in 2015 UK
LARP

19. First test of CC (ODU-SLAC at J-LAB)

20. RF-Dipole Nb prototype
“Crab Kissing” Scheme
RF-Dipole Nb prototype
DQWR prototype
17-Jan-2013
New crossing strategy under study to soften the pile-up density:
some new schemas have interesting potential as “crab-kissing”, to be discussed with all experiments
“Pile-up at HL-LHC and possible mitigation” Stephane Fartoukh on Wed. 2nd Oct.
USLUO, November 2013

21. CC Cryomodules
UK Concept
BNL Concept D2 Q4 IP
11 meters

22. SPS Test ( )
Cryo layout

23. High Bandwidth Feedback System
The high bandwidth feedback system is a proposed feedback system for the SPS, which leverages LARP experience with the LHC LLRF system, to address intra-bunch instabilities
Proposal
LARP will continue R&D related to the system.
The deliverable would be a functional feedback system the SPS, for which
The US contribution would be the complete, full-function, instability control system hardware, firmware and software necessary to operate at the SPS (and potentially LHC, PS).
The CERN contribution will include the vacuum structures (pickup(s) and kicker(s)) and all tunnel related cable plant.

24. Conclusion
Strong domestic program and collaboration with CERN for HL-LHC upgrade
First proposal for down-selection of deliverables
IR quads
Crab cavities
High Bandwidth Feedback System
LARP tasked with risk reduction in in preparation for Project era (‘18-’22).
LTSW – FSU, November 2013