1. The status of the CEBAF Upgrade Fulvia Pilat
TTC Meeting – JLAB November

2. Outline Introduction to JLAB and the 12 GeV Upgrade
Timeline and present status
C100 cryomodule: design, production, performance
What was done differently for C100 program
RF, Cryogenics, magnets
New SRF infrastructures
JLAB future plans:
12 GeV commissioning and physics running
Electron-ion Collider

3. Jefferson Lab At-A-Glance
Created to build and Operate the Continuous Electron Beam Accelerator Facility (CEBAF), world-unique user facility for Nuclear Physics:
Mission is to gain a deeper understanding of the structure of matter
Through advances in fundamental research in nuclear physics
Through advances in accelerator science and technology
In operation since 1995
~1,400 Active Users
178 Completed Experiments to-date
Produces ~1/3 of US PhDs in Nuclear Physics (406 PhDs granted, 180 more in progress)
Managed for DOE by Jefferson Science Associates, LLC (JSA)
Human Capital:
~800 FTEs
22 Joint faculty; 27 Post docs; 14 Undergraduate, 33 Graduate students
K-12 Science Education program serves as national model
Site is 169 Acres, and includes:
83 SC Buildings & Trailers; 749K SF
Replacement Plant Value: $331M
FY 2011:
Total Lab Operating Costs: $185M
Non-DOE Costs: $13M

4. CEBAF overview
In more detail
Three interleaved beams, each 499 MHz
From 180 mA in Hall C/Hall A, to a few nanoamps in Hall B.
Wien Filter: If E/B= bc the no deflection but spin precesses in plane of the electric field.
Note multiple energies in the same RF bunch in the linacs, separated in the bends.
First large high-power CW recirculating e-linac based on SRF technology
In operations since 1995  served ~1400 nuclear physics users
Capabilities: 5 passes, multiple energies, beam characteristics, polarization
3 Halls running simultaneously
Upgrade to 12 GeV: proposal late 1990’s  approved and funded in 2004

5. Enhanced capabilities
The 12 GeV Upgrade
Upgrade is designed to build on existing facility: vast majority of accelerator and experimental equipment have continued use
New Hall
Add arc
Enhanced capabilities
in existing Halls
Add 5 cryomodules
20 cryomodules
Upgrade arc magnets
and supplies
CHL upgrade
Maintain capability to deliver lower pass beam energies: 2.2, 4.4, 6.6….
The completion of the 12 GeV Upgrade of CEBAF was ranked the highest priority in the 2007 NSAC Long Range Plan.
Scope of the upgrade includes:
Doubling the accelerator beam energy
Doubling the injector energy
New Hall and beam-lines
Upgrades to existing Experimental Halls

6. 6 GeV CEBAF
help me
Two 0.6 GV linacs

7. Upgrade magnets and power supplies
12 GeV Cebaf
Upgrade magnets and power supplies
CHL-2
help me
Two 0.6 GV linacs
1.1
New cryomodules get new rf zones

8. 6 and 12 GeV CEBAF Parameter Unit 6 GeV 12 GeV
Maximum energy to Halls A, B, C /D
GeV 6 12
Number of passes for Halls A, B, C / D 5
5 / 5.5
Maximum current to Halls A, C / B mA
200 / 5
85 / 5
Emittance at max energy H / V
nm-rad
1 / 1
10 / 2
Energy spread at max energy
10-5
2.5
50 at 11 GeV
500 at 12 GeV
Bunch length (rms) ps
0.2 ~1
Polarization % 80

9. Hall D
BCAL
CDC
FDC
TOF
FCAL
start counter

10. Hall C SHMS = “Super High Momentum Spectrometer”
Halls B and C
Hall B CLAS12 = CEBAF Large Acceptance Spectrometer
Hall C SHMS = “Super High Momentum Spectrometer”
Key Features:
1 torus & 1 solenoid magnet
new detectors: Cerenkovs, calorimeters, drift chambers, silicon vertex tracker
-- re-use some existing detectors
hermetic device, low beam current, high luminosity
Key Features:
3 quadrupole & 1 dipole & 1 horizontal bend magnet
new 6 element detector package
complementary to existing spectrometer (HMS)
rigid support structure
well-shielded detector enclosure

11. 12 GeV Upgrade Schedule 16-month installation May 2012 - Sept 2013
FY12: reduction of $16M
FY13: Pres Request – no restoration
16-month installation
May Sept 2013
Hall A commissioning start Feb 2014
Hall D commissioning start
Oct 2014
Halls B & C commissioning Apr 2015
Project Complete June 2015

12. 12 GeV Upgrade organization and status
12 GeV Project, with project management structure and practices
Total Project Cost: 310 M$ (Injector Upgrade off project)
Project 68% complete, 79% obligated
Upgrade to 12GeV planned over 2 operations shutdowns:
6 months (May-Nov 2011) and 16 months (May 2012 – Sep 2013)
Run last 6 GeV physics run (Nov 2011-May 2012)
Test in operations critical upgrade components (C100 cryo-module and reworked and new magnets)
Vast scope of work ongoing concurrently at JLAB during shut-downs (12 GeV upgrade, running of FEL, construction of a 30 M$ Facility, 2 buildings to integrate engineering capabilities and doubling the SRF infrastructures
Lab-wide coordination of shutdown activities
6- month shutdown a success, exceeded scope of work in magnet upgrade

13. Cryomodule production Cryomodule test and performance
The C100 cryomodule
Cavity production
Cryomodule production
Cryomodule test and performance

14. C100 SRF cavities Q is BCS-limited
C100: string of 8 7-cell cavities, 1497 MHz, produced by RI (Research Instruments) 80 cavities + 8 pre-production tested and assembled at JLAB 18-step qualification process EP derived from ILC R&D The cavity tests are performed at the Vertical Test Area (VTA) Design gradient: 19.2 MV/m average Average heat/cavity: 29 W Operational limit: 25 MV/m (limited by the klystron RF power and possibly field emission)
Q is BCS-limited

15. Storyline for 12 GeV Cavities
Design and prototypes
After prototype set, cavity design optimization to adjust input coupling, reduce fundamental field at HOM couplers (thermal issue), and get as-welded cavity closer to target frequency.
Default surface prep: heavy BCP [all tests met project requirements]
Outside-of-project effort to apply controlled EP encouraged by ILC R&D work, also streamlined preparation process developed.
Result: Increased Q in the 17 – 24 MV/m range from EP added Technical Contingency in cryoload with minimal, if any, cost impact  Project acceptance.
Cavity acceptance test performance exceeded requirements.
Principal remaining performance-limiting phenomenon was field emission, but none with enough significance to not meet project requirements.

16. 12 GeV cavities production process
Production process: press for reliable efficiency
160 µm BCP and pre-tuned by vendor
Receipt inspection – mechanical and rf
Bake: 600 C, 10 hrs
EP: 30 regulated by external water spray
Tune
Helium vessel welding
Flange lapping
HPR
Partial assembly
HPR --> dry in Class 10 cleanroom
Final assembly, leak check
Bake: 120 C, 24 hrs
Vertical 2.07 K
HPR dry in Class 10
String assembly

17. 12 GeV cavities: overall performance

18. 12 GeV cavities: field emission
At 20 MV/m in vertical acceptance test:
Average radiation level of 190 μSv/hr (19 mrem/hr) at the top plate
(median ~ 1 mrem/hr)
35% showed no detectable radiation

19. Cryomodule design and production
The design of the C100 is an evolution from the C20 CEBAF cryomodule Experience from the C50 program (reduce field emission and raised gradient from 5.5 MV/m to 12.5 MV/m for 10 of the weakest C20 cryomodules) Output needed: 98 MV, designed for 108 MV Primary components procured, assembly and qualification at JLAB

20. C100 production status (10/2012)
Cryomodule
Assembly
Acceptance test CMTF
Installation
Tested in tunnel
Tested with beam
C100-1 ✔
✔Aug 2011
C100-2
✔Sep 2011
C100-3
In progress
Jan 2013
C100-4
✔Jun 2012
C100-5
✔May 12
C100-6
Dec 2012
C100-7
C100-8
C100-9
Final stage
C100-10
R100 (inj)

21. C-100 Cryomodule Assembly

22. Cryomodule tests and performance
Acceptance test (in CMTF, CryoModule Test Facility): every cavity is tested and tuned to 1497 MHz, HOM are characterized and maximum gradient, field emission and Qo measured together with microphonics and static heat loads Tunnel test: subset of acceptance tests Microphonics Peak detuning budget is 35 Hz Measurements within specs but higher than expected (no stiffening rings in cavities?) Modification of tuners from cryomodule 5 resulted in 42% decrease in microphonics average peak HOM measuments The predicted BBU threshold is 26 mA (nominal 465 mA maximum beam loading) Dedicated beam test at ½ energy and a special optics aimed at lowering threshold, BBU not detected. Survey of HOM(TE111,TM110 and TM111) via BTF measurements

23. 12 GeV Upgrade Cryomodule Performance
Results from the first four cryomodules commissioned
M. Drury et al. LINAC12 MOBP030

24. 12 GeV Upgrade Cryomodule Performance
Cryomodule Energy Gain (MeV)
2.07 K
Acceptance
Test in Tunnel
Ops
C100-1
111.7
104.3
94.5
C100-2
117.5
109.6
108
C100-3
118.7
C100-4
115.1
105.8
C100-5
108.2
109.9

25. Microphonics Cavity C100-1-5 Cavity C100-4-5
Determines the Feedback Gain needed for control.
Effects are driven by QL and the available klystron power for lightly loaded cavities
Microphonic
Detuning*
C100-1
C100-4
RMS (Hz)
2.985
1.524
6s(Hz)
17.91
9.14
Minor change to the tuner pivot plate substantially improved the microphonics for the CEBAF C100 Cryomodules.
While both meet the overall system requirements the improved design has a larger RF power margin
Cavity C
How one determines klystron margin in lightly loaded cavities.
Good shot of the cavities doing their own thing. Not vector sum friendly!
Point out the stiffened tuner in C100-4 and the impact on the better microphponics.
Mechanical modes at 11, 22 and 43 Hz (check with Kirk) are seen on the graphs.
Cavity C

26. Cryomodule commissioning and operations
2 C100 installed during the 6 months shutdown Commissioned and in operations Nov 2011-May 2012 Challenges: narrower bandwidth, higher gradient, coupling Learning curve (LLRF, trip recovery, etc.)
C100 Cryomodule Energy Gain – May 18th
Beam Current/pass (mA)
– 150
ENERGY GAIN (MeV)
– 50
– 100
– 200
98 MeV
108 MeV
C100 reached design energy gain (108 MeV) for the nominal 12 GeV current
of 465 mA on May
Full validation of the C100 design.

27. Quick glance at other upgrade systems: RF Cryogenics Magnets

28. RF Zone

29. RF Installation – South Linac
Four zones installed and commissioned

30. RF Installation – South Linac Tunnel
Waveguide installation

31. Magnets for 12 GeV East Arc West Arc
Magnets in existing arcs (1-9) able to work saturated (low passes) or needed re-work (higher passes). Add iron to turn C-magnets in H-magnets New arc 10, spreaders and recombiners and X-fer lines need new magnets Re-worked magnets, reinstalled in 2011, performed as predicted.
East Arc
West Arc

32. Cryogenic plant doubling
CHL Compressors are installed and are being commissioned.

33. Cryogenic plant doubling
Installation of Cold Boxes nearing completion.
UPPER COLDBOX
LOWER COLDBOX

34. New SRF infrastructures

35. New SRF infrastructures at JLAB
2 buildings (SLI program, 30 M$ investment):
TEDF (Technology Engineering Development Facility)
TLA (Test Lab Addition sft addition to TestLab)
(8600 sft chemroom / cleanroom)
Energy efficiency
Life-safety code compliance
Work-flow efficiency
Facility sustainability
Human work environment
Technical quality of facilities for future work
Cavity fabrication and cryomodule assembly
Completely new infrastructures
Phase 1: existing equipment and tools
Phase 2: incremental acquisition of new equipment and tools
TEDF occupancy: beginning 2012
TLA occupancy: summer 2012
TestLab renovation: summer 2013

36. Improved Work-Flow Efficiency
Improved work flow of SRF work centers by consolidating to Test Lab Addition (TLA)
All work centers placed on first floor level with planned adjacencies to improve work flow
SRF machine shop, presses, tech shop, and electron beam welder consolidated to west end of TLA
Brazing and vacuum furnaces moved to one room
Parts clean & etch, R&D chemistry co-located to east end of TLA with improved integration with clean room
Consolidated R&D labs with similar purposes
Vertical attach clean room isolated from main ISO-4 clean room used for cavity processing and assembly via an air lock
Longer dedicated cryomodule assembly rail systems to enable simultaneous activities

37. SRF Facilities in JLab TEDF
TEDF Project
SRF Facilities in JLab TEDF
Chemistry, cavity treatments, and support areas
R&D
Advanced Conceptual Design 4/1/09
Cavity and cryomodule cryo/RF testing
Cleanroom
Fabrication
Cryomodule assembly
New

38. SRF Work Centers in New Test Lab
Physics
Cryomodule Test
Vertical Test Area & Electronics Shop
Cryomodule Assembly
1st and 2nd Floor Offices
Vertical Attachment
Parts Clean and Etch
R&D Chem Lab
R&D Labs
QA/CMM & Tuning
Process Support Area
Clean Room
R&D Clean Lab
Fabrication
Machine Shop
Electron beam Welding
Furnaces

39. JLAB future plans Short (2012-2014)
install and commission 12 GeV machine
Medium (2015 – 2030)
Run 12 GeV physics program (50+ experiments approved)
Exploit SRF core capabilities and new infrastructures work for others
Prepare EIC (Electron Ion Collider)
Long (2030+)
“Bid for” and build a EIC at JLAB

40. Electron collider ring
Medium Energy
JLab Concept
Initial configuration (MEIC):
3-11 GeV on GeV ep/eA collider
fully-polarized, longitudinal and transverse
luminosity: up to few x 1034 e-nucleons cm-2 s-1
Upgradable to higher energies (250 GeV protons)
Pre-booster
Ion
source
Transfer beam line
Medium energy IP
Electron collider ring
(3 to 11 GeV)
Injector
12 GeV CEBAF
SRF linac
Warm large booster
(up to 20 GeV)
Cold ion
collider ring
(up to 100 GeV)

41. Jefferson Lab Electron Ion Collider
Activity Name
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
12 GeV Upgrade
FRIB
EIC Physics Case
NSAC LRP
EIC CD0
EIC Machine Design/R&D
EIC CD1/Downsel
EIC CD2/CD3
EIC Construction

42. Conclusions
The 12 GeV Upgrade for CEBAF at JLAB is progressing well and the start of commissioning is planned for the fall of 2013.
A robust program of physics running will follow.
JLAB will complete a doubling of its SRF infrastructure in summer 2013 greatly enhancing its future SRF R&D and production capabilities.
An electron-ion collider is the long-term strategic goal of the laboratory.
The conceptual design for a MEIC at JLAB has
been published in August 2012.

43. Acknowledgements
All JLAB staff working towards the 12 GeV Upgrade for their scientific and technical input For direct contributions to the slides: M. Drury, J. Guo, J. Hogan, K. Hovater, W. Merz, H. Montgomery, C. Reece, T. Reilly, C. Rode, T. Satogata.

44. Backup slides

45. 12 GeV cavities
“Yield” from VTA testing
Only one cavity required a second EP – that due to HPR wand strikes – then fine: C100-8
2 – fab. geometry issues
1 – quench 19 MV/m
Field emission
cleaned-up with
2nd HPR
“Nb surface” prep was not an issue, but reliable cleanliness and cryo leaks were

46. Microphonics First 4 Cavities Cryomodule C100-1 Last 4 Cavities
Several resonance modes in the structure
10 Hz mode was a dominate mode which involved the entire string.
The first half of the string was 180° out of phase with the second half of the string
Last 4 Cavities
How one determines klystron margin in lightly loaded cavities.
Good shot of the cavities doing their own thing. Not vector sum friendly!
Point out the stiffened tuner in C100-4 and the impact on the better microphponics.
Mechanical modes at 11, 22 and 43 Hz (check with Kirk) are seen on the graphs.
Can be a driver for RF power and field control issues.
Must be measured in situ with a complete cryomodule
Sometimes it is possible to address problems with minor fixes.

47. SRF Work Centers in Test Lab
Fabrication
Physics
Electron Beam Welding
Machine Shop
R&D Clean Labs
Offices
R&D Chem Lab
Cryomodule Test
Cryomodule Assembly
Parts Clean & Etch
Clean Room(s)
Electropolish
Weld Shop
QA/CMM
Vertical Test Area & Electronics Shop
Test Lab 1st Floor
R&D Lab
Tuning & Furnace
Work Stations
(3rd flr)
Test Lab 2nd Floor
R&D Labs
Offices