Advanced Low Emittance Rings Technology workshop ALERT 2014

Advanced Low Emittance Rings Technology workshop (ALERT 2014) NEG-coating for MAX IV Marek Grabski 6 th May 2014 Valencia, Spain ALERT 2014 workshop, 5 -6 May Marek Grabski 1

Contents • • • Machine layout, Vacuum system design, NEG-coating R&D at CERN, Production status, Installation procedure - brief, Summary. ALERT 2014 workshop, 5 -6 May Marek Grabski 2

MAX IV layout Short pulse facility Linac 1. 5 Ge. V ring 3 Ge. V ring https: //www. maxlab. lu. se/maxiv ALERT 2014 workshop, 5 -6 May Marek Grabski 3

3 Ge. V ring layout Emittance measurement Injection Emittance measurement Circumference 528 m, 100 MHz RF cavities 20 achromats, 19 straight sections available for IDs. 300 MHz RF cavities ALERT 2014 workshop, 5 -6 May Marek Grabski 4

3 Ge. V magnet layout Photon beam One 7 -bend achromat One achromat, ~26 m long Beam direction U 2, VC 4 Sextupole Dipole BPM Ø 25 Magnet apertures Ø 25 mm ALERT 2014 workshop, 5 -6 May Marek Grabski Ø 22 Min. clearance with the iron 0. 5 mm, min. clearance with the coils 2 mm. 5

Standard vacuum chamber geometry One achromat VC 5 Beam direction VC 5 chamber Inside diameter: 22 mm, Total length: ~2. 5 m, Welded bellows Chamber body Bent part: Arc length 1 m, Bending angle 3 0, Bending radius 19 m. am Be n tio c e ir d Ribs Welded bellows Bent part Cooling for corrector area Distributed pumping and low PSD, utilizing thin film NEG-coating. Distributed cooling Cooling for corrector area ALERT 2014 workshop, 5 -6 May Marek Grabski NEG coating 6

NEG-coating R&D at CERN Three stages of NEG-coating (Ti, Zr, V) by magnetron sputtering validation in collaboration with CERN were undertaken: 1. Define and perform initial surface treatment of copper substrate. 2. Validate compatibility with NEG-coating: a). On Copper substrate. b). On Wire-eroded surfaces and used brazing alloys. 3. Neg-coating validation of the vacuum chamber geometry. ALERT 2014 workshop, 5 -6 May Marek Grabski 7

1. Surface treatment (R&D at CERN) 1. Define and perform surface treatment of the OFS copper tubes (~300 tubes) basing on experience with LHC. Chosen treatment: 1 st step - degreasing, 2 nd step - etching and passivation. * Due to presence in the final chambers welded bellows the surface treatment was done prior to the final manufacturing. Degreasing: UHV compatible Bellows Not yet NEG-coating compatible Etching: Passivation: reated t s e b u ~300 t ERN, at C carded s i d Etching removed about 50 μm of the material % 10 ALERT 2014 workshop, 5 -6 May Marek Grabski NEG coating compatible Ready for manufacturing 8

2. Material compatibility (R&D at CERN) 2 a). Confirm compatibility of NEG-coating on etched OFS copper substrate. Two 3 m long OFS copper chambers (degreased and etched) were coated with NEG. OFS Copper chambers during thermal cycling 10 times thermally cycled up to 2000 C for at least 12 h and vented with air between the cycles. Chamber before coating Chamber after coating and thermal cycling NEG-coating el-offs e p o N ed observ ALERT 2014 workshop, 5 -6 May Marek Grabski 9

2. Material compatibility (R&D at CERN) 2 b). Evaluate compatibility of coating on wire-eroded surfaces and used brazing types. Wire-eroded copper samples (coating and measurements): Small samples (for XPS): As received: Vacuum chamber: Installed for NEG-coating: NEG-coating Adhesion and activation - OK Pumpdown and outgassing by accumulation measurements performed. c). Brazing types: Outgassing as clean metallic surface 2 brazing alloys tested: Ag and Ni based. Adhesion - OK ALERT 2014 workshop, 5 -6 May Marek Grabski 10

3. Geometry validation (R&D at CERN) 3 a). Validation of coating with NEG (Ti, Zr, V) of 22 mm inside diameter vacuum chambers. Coating of 1 m long, 22 mm diameter tube by magnetron sputtering: Feedthrough Sample (Cu) NEG-coating Glow discharge plasma during coating process. 1 m substrate 20 cm extension Courtesy of Antonios Sapountzis, CERN Pumping dome 1 mm Ti, Zr, V wires ALERT 2014 workshop, 5 -6 May Marek Grabski 11

3. Geometry validation (R&D at CERN) 3 a). Validation of coating with NEG (Ti, Zr, V) of 22 mm inside diameter vacuum chambers. Sticking factor evaluation for hydrogen. Measurement system Pend NEG coated chamber (1 m) Pinj Measurement results: Pressure ratio (d. Pinj)/(d. Pend) versus sticking factor ible to s a e f e ar mbers sputtering, a h c m n • 22 m by magnetro coat r OK. o t c a f king • Stic ALERT 2014 workshop, 5 -6 May Marek Grabski 12

3. Geometry validation (R&D at CERN) 3 a). Coating validation of 22 mm inside diameter bent tubes. 0. 65 m 1 m 0. 65 m 30 r=19 m Upper extension and feedthrough 3 ceramic spacers Lower extension with weight and centering NEG film thickness distribution (measured by XRF): tory tisfac tion sa istribu d s s e Thickn SEM thickness measurements: Top 0. 7 μm ALERT 2014 workshop, 5 -6 May Marek Grabski Bottom 1. 2 μm 13

3. Geometry validation (R&D at CERN) XPS results from the coatings of 22 mm inside diameter and bent chambers showed good composition and activation behavior. ation v i t c a n and tory o i t i s o Comp vior satisfac beha Samples used for characterisations O 1 s peak as a function of temperature CERN reference O 1 s peak (A. U. ) Metallic concentration (at. %) Surface metallic composition by XPS Coated chambers ALERT 2014 workshop, 5 -6 May Marek Grabski CERN reference 0 Activationtemperature( (0 C) C)– 1 h 14

3. b) Complex vacuum chambers (R&D at CERN) 3 b). Establish coating procedure/technology and produce chambers of complex geometry: Vacuum chamber for beam extraction. BPM Crotch absorber BPM VC 2 Photon beam Beam direction Aperture limiting sextupole ALERT 2014 workshop, 5 -6 May Marek Grabski VC 2 a VC 2 b 15

3. b) Complex vacuum chambers (R&D at CERN) Chamber exit Chamber entrance Prototype made was made at CERN in two halves to be able to inspect the coating quality. Glow discharge during coating 0. 75 m ü Thickness – OK, ü Coverage - OK, X - ‘delayed‘ activation Due to difficulties with coating – chamber for coating was divided and will be coated in 2 runs. VC 2 a ALERT 2014 workshop, 5 -6 May Marek Grabski VC 2 b 16

3. b) Complex vacuum chambers (R&D at CERN) VC 1 and VC 2 L will be coated in the coating systems for LHC Series coating of complex chambers. VC 2 A and VC 2 B will be coated in a dedicated system VC 2 B VC 2 a VC 2 A VC 1 5 x. VC 2 L VC 2 b Courtesy of: Pedro Costa Pinto, Sergio Daniel Marques dos Santos - CERN Production started, first chamber (VC 1) was coated mid-April. Production planned to finish in November 2014 ALERT 2014 workshop, 5 -6 May Marek Grabski 17

NEG-coating series production Beam direction Photon beam VC 10 VC 2 achromat 3 Ge. V - 1 One achromat (~26 m) VC 4 Main vacuum chamber types: 1. Standard bent vacuum chambers (VC 4) - 1. 50 and 30 bends, Industry (70% length wise) Ø 22 mm 2. 8 m (VC 4) 30 Ø 22 2. Straight vacuum (VC 10)chambers, 17. 2 mm Collaboration with ESRF (15%) 2 m (VC 10 B) BPM 3. Special vacuum chambers. Collaboration with CERN (15%) ALERT 2014 workshop, 5 -6 May Marek Grabski VC 2 Photon beam Electron beam 18

Production status at FMB is the manufacturer of vacuum chambers for MAX IV and also does the NEG coating. • Manufacturing of components, • Final cleaning of the vacuum chambers and welding bellows, • Dimensional and vacuum testing, • NEG-coating. Crotch absorbers: VC 1 dimensional check: In 2012 FMB purchased the license for NEG coating from CERN and proved its ability to deliver coated chambers within specifications. Launch of the NEG-coating campaign depended on the approval of the vacuum chamber final cleaning. After many trials and discussions the cleaning was approved by CERN on the 2 nd December 2013. Currently about 70% of 750 chamber units are produced ALERT 2014 workshop, 5 -6 May Marek Grabski 19

Production status at FMB After approval of the cleaning procedure the series cleaning of the chambers started and final manufacturing steps were completed and the NEG-coating was started. Two coating towers available at FMB: Coating tower 1 VC 8 G, VC 10 C Coating tower 1 3 x. VC 5 – preparation for coating (21 units to coat) Coating tower 2 ALERT 2014 workshop, 5 -6 May Marek Grabski 20

Production status at FMB Quality control at FMB: Film activation properties and surface composition evaluated by XPS. The cleaning water quality is checked regularly. Composition: Chambers are being coated according to the schedule. One coating failed – new chamber was manufactured Sample from each coated chamber is characterized for: film thickness by SEM. Visual inspection by endoscope performed for all the chambers Activation curve - O 1 s peak area as a function of temperature 1. 4 μm ALERT 2014 workshop, 5 -6 May Marek Grabski 21

Activity status at ESRF To increase the coating throughput and perform vital measurements of NEG-coated chambers collaboration with ESRF was established. One new coating tower was built and commissioned at ESRF that will be used for ESRF future upgrade. Coating of 11 BPMs in series Courtesy of: H. P. Marques, M. Hahn - ESRF ALERT 2014 workshop, 5 -6 May Marek Grabski 22

Activity status at ESRF NEG-coated OFS copper chamber Photon beam Yield (mol/ph) Photon stimulated desorption (PSD) measurements at ESRF at beamline D 31. NEG-coated OFS copper chamber Courtesy of: H. P. Marques, M. Hahn - ESRF MAX IV Chamber, OFS Cu, 3 m, Ø 25 mm At dose 4 e 22 ph/m PSD yield = 1 e-5 mol/ph Dose (ph/m) CERN chamber, 316 LN, 2 m, Ø 60 mm Measurement results: • PSD yield of the tested chamber is higher as expected, • The conditioning of MAX IV chambers seems to be slightly faster. ALERT 2014 workshop, 5 -6 May Marek Grabski At dose 4 e 22 ph/m PSD yield = 2 e-6 mol/ph ‘Synchrotron Radiation-Induced Desorption from a NEG-Coated Vacuum Chamber’, P. Chiggiato, R. Kersevan 23

Installation - 3 Ge. V ring Installation will be rehearsed in a mock-up of one achromat. ALERT 2014 workshop, 5 -6 May Marek Grabski 24

Installation view Strongback ALERT 2014 workshop, 5 -6 May Marek Grabski 25

Summary • R&D was needed - possible thanks to collaboration with CERN. • Coating being done in 3 different places – beneficial for the production throughput. • Single manufacturer of all the chambers and provider of the NEG -coating for ~70% of chambers. • NEG-coating production started. First series coating in January 2014. • NEG-coating quality control showed three issues so far. • PSD measurement results at ESRF show higher yield as was expected, however the conditioning seems faster. • NEG-coating should to be considered at the beginning of the design as it implies limitations to the design. The earlier the NEG-coating is considered in the design - the easier and less risky will be the manufacturing, integration and installation. ALERT 2014 workshop, 5 -6 May Marek Grabski 26

Thank you for your attention Acknowledgment: Jonny Ahlbäck, Eshraq Al-Dmour, Dieter Einfeld, Pedro F. Tavares (MAX IV), Pedro Costa Pinto, Sergio Daniel Marques dos Santos (CERN), PKAB, ALBA, ESRF, Solaris and MAX IV staff ALERT 2014 workshop, 5 -6 May Marek Grabski 27