ESS-Bilbao: MEBT vacuum standarization LUND, 19-20 February2014 Aitor Zugazaga and Igor Rueda

ESS-Bilbao Vacuum overview DTL 10-8 mbar MEBT 10-8 mbar RFQ 10-7 mbar LEBT 5x10-5 mbar Ion Source 5x10-5 mbar

Test-Stand Vacuum • Ion Source + LEBT: in 5x10-5 / out 1x10-7 mbar • 1 primary EDWARDS iXH 4545HT • 4 (Up-to 6) Hi pace 700 (600 l/s )+ 1 HiPace 2300 (2800 l/s) •RFQ: 10-7 mbar • Up to 4 Hi Pace 700 (600 l/s)

Leak test Leak detector: Phoenixl 300 CERN (AVS): CERN (CADINOX): Scrapper CERN (CADINOX): DTL tank Leak detector: Phoenixl 300 IFMIF (HTS): Buncher cavity HTS: RF cavity

Superconducting Solenoids Other Vacuum test ALBA: Mylar window RF Coupler TECNALIA: Superconducting Solenoids

Simulations courtesy of Igor Madariaga (ESS-Bilbao PPT) Pump selection • Simulations using Molflow + (R.Kersevan from CERN vacuum group) • Temperature: 300 K • Calculated approximate leak rate using empirical formulas proposed by NASA 10-7mbar l/s RFQ (1st segment) LEBT (1st vessel) Simulations courtesy of Igor Madariaga (ESS-Bilbao PPT)

MEBT cavities with connection tube Pump selection • Simulations using Molflow • 3,5 m long • 3 Ion Pumps (34 l/s) • Gas molecula mass (air) = 28g/mol • Outgasing/area = 1x10-8 l/s/cm2 MEBT cavities with connection tube Simulations courtesy of Igor Madariaga (ESS-Bilbao PPT)

Cleaning Procedure • Based on CERN’s document LHC-VN-FP-0005-10-00 • Remove mechanically all major contamination on the surfaces • Degrease by immersion in detergent solution in an ultrasonic bath if possible • Rinsing with demineralised water jet • Drying in oven if possible or with compressed air • Rinsing with acetone, ethanol and iso-propanol Oven Ultrasonic bath

Seals • CF: • Helicoflex: • Wherever possible • Commercial • Leak rate: < 1.0E-11 mbar l/s • Helicoflex: • In singular cases as the assembly of the 2 parts of the cavity and the connection between the tube and the cavity • Technetics or HTMS • PEEK: • In a singular case for RF transmission • Same principal of the CF flange

Valves & Gauges • Valves: • Gauges: • Pfeiffer PKR 251 CF40 • VAT Mini UHV Gate Valve (01032-CE44) CF40 • VAT UHV gate valve (10844-CE44) CF160 • Leak rate: Body < 5.0E-10 mbar l/s Valve seat< 5.0E-9 mbar l/s • At the beginning and the end of the MEBT • As point of connection with the RFQ and the DTL • Connection with the preliminary turbo pump • Gauges: • Pfeiffer PKR 251 CF40 • Oerlikon ITR 90 CF40 •Connected to the distribution tube

Interfaces • Wire Scanner • Cavity • Scrapper Diagnostics (CF) A Line connection (CF) B • Cavity Vacuum port (CF) A Tuners - Coupler (CF) B Line connection (Helicoflex) C B A A B C B A • Scrapper Shutters (CF) A Line connection (CF) B Scrapper courtesy of AVS

Interfaces • Beam Dump • Chopper Line • Gauge Line connection (CF) A Chopper Line and Beam Dump courtesy of CERN

Materials and welding selection • AISI 304: •To make easier the welding process and sealing with CF. • Copper plate the buncher interiors for RF properties. (According to CERN’s L4-AC-CC-0002-10-00) • Outgassing rate after 10 h pump-down inferior to 2×10-9 mbar.l.s-1.cm-2 •TIG & EBW •Possible modifications: •In case the copper plating option doesn’t result as expected made the cavity in OFE Copper. - No need of Copper Plating - Brazing for CF flanges to the cavity. Plating test courtesy of INNOMAT COATINGS

Flange to flange distances B C D E F G H C I J E K G L M E G O C P A • A: 35mm  Valve • B: 537mm  QUAD + TRAFO + QUAD • C: 33mm  Wire Scanner • D: 238mm  QUAD • E: 180 mm  Buncher • F: 234 mm  QUAD • G: 80 mm  Scrapper • H: 975 mm  Chopper • I: 203 mm  Collimator • J: 205 mm  QUAD • K: 343 mm  QUAD+QUAD • L: 471 mm  Diagnostic Box • M: 149 mm  QUAD • N: 64 mm  Transition • O: 251 mm  QUAD • P: 329 mm  TRAFO + QUAD

Vacuum Procedure Mechanical Pump: TRIVAC D 65 B Turbo Pump: HiPace 700 VAT Mini UHV Gate Valve 01032-CE44 Ion Pumps: NexTorr D300-5 Turbo Pump: HiPace 700 Mechanical Pump: TRIVAC D 65 B VAT UHV gate valve 10844-CE44 PKR 251 / ITR 90 Vacuum cart courtesy of Gorka Mujika (ESS-Bilbao PPT)

Vacuum Procedure CF 63 Bellow (Cavity-Tube) Line Tube DN 35 in AISI 304 Bellow-Tube welding Electron beam QUADs can be opened Leak detection with the Phoenixl 300 DN 40 Bellow (Line tube) Fixed supports

ESS-Bilbao: MEBT vacuum standarization LUND, 19-20 February2014 Aitor Zugazaga and Igor Rueda