LCLSII Cryogenic Systems Cryomodule Distribution and Cryoplant Greg

LCLS-II Cryogenic Systems: Cryomodule, Distribution, and Cryoplant Greg Hays 5 th Open Collaboration Meeting on SLHi. PP 18 -19 March 2015

Outline • LCLS-II Project • Cryomodule Design • High Q 0 Program • Cavity Integration & Prototype Production • Cryoplant • Cryogenic Distribution System • Summary LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 2

LCLS-II will install a CW SCRF linac in the 1 st km of the SLAC tunnel. LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 3

LCLS-II Accelerator Layout and Modifications LCLS-II Linac SCRF 4 Ge. V proposed FACET-II LCLS-I Linac 2. 5 -15 Ge. V Sec. 11 -20 Sec. 21 -30 0. 2 -1. 3 ke. V (0. 1 -1 MHz) SXU HXU 1 -25 ke. V (120 Hz) 1 -5 ke. V (0. 1 -1 MHz) • New Injector, SCRF linac, and extension installed in Sectors 0 -10 • Use existing Bypass line from Sector 10 to Beam Switch Yard • Re-use existing high power dump in Beam Switch Yard • Add magnetic kicker to direct beams to dump or either undulators • Add new variable gap undulators: Hard (HXR) and Soft X-ray (SXR) • Re-use existing transfer line to HXR; modify HXR dump • Construct new transfer line to SXR; install new dump • Modify existing LCLS-I X-ray optics and build new SXR X-ray line LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 4

Project Collaboration LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 • • • 50% of cryomodules: 1. 3 GHz Cryomodules: 3. 9 GHz Cryomodule engineering/design Helium distribution Processing for high Q (FNAL-invented gas doping) • • • 50% of cryomodules: 1. 3 GHz Cryoplant selection/design Processing for high Q • • Undulators e- gun & associated injector systems • • • Undulator Vacuum Chamber Also supports FNAL w/ SCRF cleaning facility Undulator R&D: vertical polarization • • • R&D planning, prototype support processing for high-Q (high Q gas doping) e- gun option 5

LCLS-II Linac • Thirty-five 1. 3 GHz 8 -cavity cryomodules • Two 3. 9 GHz 8 -cavity cryomodules • Four cold segments (L 0, L 1, L 2 and L 3) which are separated by warm beamline sections. LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 6

LCLS-II will use 1. 3 GHz cryomodules. • Use existing designs to the extent possible to optimize cost and schedule - LCLS-II SRF linac closely based on XFEL / ILC / TESLA design - Under development ~ 20 years with > 1000 cavities to be made and tested (incl. 800 for Eu. XFEL – completed 2015) • FNAL has been working with these designs for ~10 years in ILC context - Two 1. 3 GHz cryomodules built and tested: CM 1 and CM 2 - Significant improvements to lab infrastructure to support SCRF development and Production • JLAB has built ~100 SCRF cryomodules over the last 30 years - JLab CEBAF and 12 Ge. V Upgrade machines - SNS Ø FNAL responsible for the CM design, in collab with JLab & SLAC Ø Procurement/fabrication/assembly/test shared by FNAL and JLab Ø Cooperation and assistance from DESY/XFEL and CEA Saclay has been extremely beneficial. LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 7

Cryomodule Modifications for LCLS-II - Components are based upon XFEL/ILC/Tesla designs • 1. 3 GHz Cavities – identical to XFEL • Helium vessel – modified ILC with bellows at end for end lever tuner • HOM coupler – similar to XFEL • Magnetic shielding – increased from XFEL to maintain high Q 0 LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 8

Component modifications for LCLS-II (continued) • Tuner – modified XFEL endlever style • Magnet – Fermilab/KEK design split quadrupole • BPM – DESY/XFEL button-style with modified feedthrough • Coupler – TTF 3 design modified for higher QL and 7 k. W CW LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 9

Cryomodule image from 3 -D model LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 10

LCLS-II Cryogenics Cryogenic system has three independent circuits: Each circuit has static heat-load (no power, no beam) and dynamic load Nominal Exp. Heat High Temp Shield (with NO uncertainty factor) (40 -80 K) [k. W] BASELINE Static heat [k. W] 7. 05 Dynamic heat [k. W] 2. 38 Total heat LCLS–II linac, [k. W] 9. 44 Design Capacity Margin Low Temp Intercepts (5 -8 K) 2. 0 K base 0. 71 0. 15 0. 86 0. 43 2. 7 3. 14 14 1. 3 4. 0 48% 51% 27% SRF Cavities operate in a saturated He-2 bath at 0. 031 mbar. ~ 70 % cryogenic power supports dynamic (RF-on) load at 2. 0 K 1/Q 0 indicates the expected 2. 0 K dynamic load LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 11

Nitrogen doping: a breakthrough in Q Record after nitrogen doping – up to 4 times higher Q! Average values obtained on nine cell Q(2 K, 16 MV/m)~ 3. 5 e 10 Standard state-of-the art preparation Typical Q obtained in VTS with 120 C bake ~ 1. 7 e 10 at 2 K, 16 MV/m 1. 3 GHz A. Grassellino et al, 2013 Supercond. Sci. Technol. 26 102001 (Rapid Communication) LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 12

2014 – Q 0 R&D Progress toward LCLS-II Factor 2 to 3 beyond state-of-the-art N 2 doping recipe specified, • supplied to prospective cavity fabrication vendors 10. 2014 Bare cavities qualified for dressing • 10 each done – out of 16 needed for cryomodule 1 and 2 • Tested in Vertical ‘Dunk’ test (VTS) • VTS: <Q 0> 3. 4 e 10; <E_accmax> 23 MV/m • (Req’d: <Q 0> 2. 7 e 10; E_accmax> 18 MV/m) Initial ‘integrated’ Horizontal Testing started LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 13

FNAL + Jlab Nine Cell 2. 0 K Results, N-doping recipe LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 14

Need to cool down fast through Tc Dressed N doped nine cell cavity vertical test at T=2 K LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 15

Cavity Integration Testing: Cool-down measurements in Cornell Horizontal Test Single-cavity test in a cryomodule-like environment LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 16

HTS high Q results 12. 2014 – 02. 2015 Cavity LHe Tank type HT Test # Q 0 - VT (e 10) Q 0 - HT (e 10) ΔR res (VT HT) nΩ TB 9 ACC 012 ILC HTS-1 (F) 3. 4 2. 8 2 TB 9 AES 011 ILC HTC 9 -1 (C) 3. 5 3. 2 1± 2 TB 9 ACC 012 ILC HTC 9 -2(C) 3. 4 2. 7 2± 2 TB 9 AES 018 LCLS-II HTS-2 (F) 3. 1 2. 1 4 TB 9 AES 018 LCLS-II HTC 9 -3(C) 3. 1 2. 2 4± 2 TB 9 AES 021 LCLS-II HTS-3 (F) 3. 3 2. 1 4 LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 17

ILC versus the LCLS-II Helium Vessel • 2 -4 extra nano. Ohms residual resistance observed with new LCLS-II vessel • What’s different? Work ongoing right now ILC style LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 LCLS-II style 18

What are the differences between the ILC and LCLS-II Helium Vessels? 1. Larger mag fields surrounding the cavity because of large use of stainless steel • SS Bracket (or tuner) • 2 phase pipe 2. Vessel welded longitudinally, bellows moved to the side and bypassed by bracket, transitions from SS to Ti potential for increasing thermal loops which generate larger fields during cool-down 3. Cooling configuration is different 4. Mag shield configuration is different (double layer) We are currently investigating and making improvements LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 19

Recent results indicate magnetic flux expulsion is dependent upon cavity cooling geometry. • Heating at the top of the cavity has been observed in both the single cell and dressed nine cell. - Single Cell Cavity in Static Magnetic Field Compatible with the ”flux hole” scenario Vertical field lines get encircled by superconducting regions and highly concentrated at the very top of the cavity • Different field orientations for same cooling geometry may have a different impact on final performance - An orthogonal magnetic field may have a larger degrading impact for RF losses than an axial component LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 http: //arxiv. org/pdf/1502. 07291 v 2. pdf 20

LCLS-II Prototype 1. 3 GHz cryomodules will be ready for testing in December 2015. • Purpose of prototypes • Test out the design modifications as soon as possible • Prove out the JLab infrastructure modifications • Develop procedures and travelers, train staff, etc. • Build two prototype cryomodules, one each at FNAL and JLab • Use 16 existing FNAL ILC 9 -cell short-short cavities (beam tube lengths) • Adapt XFEL-style end-lever tuner to short-shorts, and to permit access through ports • Design new helium vessel to accommodate end-lever tuner and larger heat load • Titanium to SS transition on chimney and fill lines • Prototype CM’s will go in the beamline and must perform to specification • He vessel and tuner may be different wrt production CM • Cryomodule production begins May 2016 LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 21

Linac Cryo-plant to be constructed near Sector 4 Sector 10 Cryoplant Cooling Tower Sector 4 LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 22

Cryoplant Building Baseline concept LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 N 40 x 25 m building 11, 200 sq feet 23

LCLS-II Cryoplant is based upon JLab CHL 2 design. Single 2 K Cryogenic Plant Leverage Existing Technology for Cost, Schedule, and Risk Temperature Capacity 2 K 4. 0 k. W 5 K to 8 K 1. 2 k. W 40 K to 80 K 13. 4 k. W Typical 2 K System LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 24

Major Equipment & Plant Layout - 4. 5 K & 2 K Cold Box 4. 5 K Cold Box (2 separate CBs) • “Upper” cold box, 300 K to 80 K - LN 2 boiler, heat exchangers, dual 80 K adsorber beds • “Lower”cold box, 80 K to 4 K - Expanders, heat exchangers, 20 K adsorber bed, subcoolers Lower 4. 5 K CB Upper 4. 5 K CB 2 K Sub-Atmospheric Cold Box • Five cold compressor stages • Variable speed motor drives Lower 4. 5 K CB (control valves, turbines) • Magnetic bearing technology LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 2 K Cold Box 25

Cryogenic Distribution System (CDS) feeds 2 cryomodule strings: Upstream (L 0 -L 2) and Downstream (L 3) CDS consists of several components • Feed Caps 6 total units Several versions – Lambda, Delta and Gamma • Three Cryogenic Bypasses • • LH (73 m) • BC 1 (63 m) • BC 2 (107 m) • • Upstream “Injector” EC γ FC λ FC δ FC LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 λ FC End Caps 2 total units Two versions – US and DS Horizontal Transfer Lines 40 foot sections ~ 20 units Anchor Modules 6 total units Anchor/Vacuum Break Vertical Transfer Lines 2 units Connection to surface components Downstream EC 26

Bypass transferline – cross section Rolled Aluminum Shield G-10 Support Aluminum Extrusion G-10 Tubes Process Circuits • Low pressure return anchored to support assembly • Other circuits slide independently in G-10 tubes • Support assembly rolls on aluminum extrusion • Aluminum extrusion rolls inside vacuum jacket • Each circuit allowed to move independently LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 G-10 Rollers Ball Transfers Support Assembly 27

Cryogenic Distribution δ Feed Cap – reference design LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 28

The Distribution Boxes house the 2 K-4 K heat exchanger, and are located in the Klystron Gallery. LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 29

Linac Tunnel Layout and Cross-section 1. 3 GHz Modules (FNAL & JLab) 3. 9 GHz CM (FNAL) LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 CDS (FNAL) 30

Summary • Record Cavity Q demonstrated • Cryomodule Integration is underway. • Prototype Cryomodules ready for testing – Dec 2015 • Long Lead Procurements have begun • Niobium Material • Cavities • Cryoplant • Cryomodule Production May 2016 thru Aug 2018 • First Cool-down of SRF Linac July 2019 • LCLS-II First Light in late 2019 LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 31

End Presentation LCLS-II Cryogenic Systems, SLHi. PP 18 -19 March 2015 32