1. ESS-Bilbao: MEBT vacuum standarization
LUND, February2014
Aitor Zugazaga and Igor Rueda

2. 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

3. 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)

4. 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

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

6. 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)

7. 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)

8. 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

9. 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

10. 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

11. 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

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

13. 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 ) • 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

14. Flange to flange distancesB 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

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

16. 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

17. ESS-Bilbao: MEBT vacuum standarization
LUND, February2014
Aitor Zugazaga and Igor Rueda