ESSBilbao MEBT vacuum standarization LUND 19 20 February

ESS-Bilbao: MEBT vacuum standarization LUND, 19 -20 February 2014 Aitor Zugazaga and Igor Rueda

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

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

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

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

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 -7 mbar l/s LEBT (1 st vessel) RFQ (1 st segment) Simulations courtesy of Igor Madariaga (ESS-Bilbao PPT)

Pump selection • Simulations using Molflow • 3, 5 m long • 3 Ion Pumps (34 l/s) • Gas molecula mass (air) = 28 g/mol • Outgasing/area = 1 x 10 -8 l/s/cm 2 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 Ultrasonic bath Oven

Seals • CF: • Wherever possible • Commercial • Leak rate: < 1. 0 E-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 • Leak rate: < 1. 0 E-11 mbar l/s • PEEK: • In a singular case for RF transmission • Same principal of the CF flange

Valves & Gauges • Valves: • VAT Mini UHV Gate Valve (01032 -CE 44) CF 40 • VAT UHV gate valve (10844 -CE 44) CF 160 • Leak rate: Body < 5. 0 E-10 mbar l/s Valve seat< 5. 0 E-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 • Oerlikon ITR 90 CF 40 • Connected to the distribution tube

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

Interfaces • Beam Dump • Line connection (CF) • Chopper Line • Line connection (CF) A A A • 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 L 4 -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 N A B C D E F G H • A: 35 mm Valve • B: 537 mm QUAD + TRAFO + QUAD • C: 33 mm Wire Scanner • D: 238 mm QUAD • E: 180 mm Buncher • F: 234 mm QUAD • G: 80 mm Scrapper • H: 975 mm Chopper C I J E K G L M E G • 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 O C P A

Vacuum Procedure Mechanical Pump: TRIVAC D 65 B Turbo Pump: Hi. Pace 700 Ion Pumps: Nex. Torr D 300 -5 VAT Mini UHV Gate Valve 01032 -CE 44 VAT UHV gate valve 10844 -CE 44 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 DN 40 Bellow (Line tube) Bellow-Tube welding Electron beam QUADs can be opened Fixed supports Leak detection with the Phoenixl 300

ESS-Bilbao: MEBT vacuum standarization LUND, 19 -20 February 2014 Aitor Zugazaga and Igor Rueda