1. Developing Particle Control Infrastructure for the ESS High Beta Cavity Project
Mark Pendleton – STFC Daresbury Laboratory
Operating SRF systems reliably in a 'Dirty' machine_Mark Pendleton_140917

2. ESS High Beta Cavities STFC In-Kind Contribution: Niobium procurement
Manage Eddy Current Scanning (DESY)
Manage the Cavity fabrication of high beta cavities in industry.
Testing at STFC: 2K RF qualification of cavities to 22.9MV/m, Q0 ≥ 5 x 109
Transport to CEA Saclay.

3. Outline Design of the Cleanroom for ESS HB cavity re-work
Modular Cleanrooms for Cryostat connections under ISO4 Conditions
SPSV systems for the Cryostat + Cleanroom

5. HPR System Comments welcome: Commissioning and Validation.
Processes and Procedures TBD
Comments welcome:
Commissioning and Validation.
Monitoring during rinse cycle.
Drying procedure - Including particle
monitoring.
Issues with filter systems.
Drainage issues with UPW.
System at CEA Saclay

6. Cryostat Insert Stand and Cleanroom facility requirements
Structure to hold 2 Cryostat inserts 1500kg, laden ~1800kg (each)
Personnel access for vacuum and electrical connections to be made on top of the cryostat.
Access for cavity lifters to load and Unload cavities between the structure support legs.
Framework to support a cleanroom solution.
Access from the ground floor or office platform including escape route.

7. Cryostat Insert

8. Solution 1: Full Cleanroom enclosure
Insert 2
Insert 1
Laminar Flow Unit
Full enclosure
Full enclosure
Changing room
Laminar Flow Unit
Laminar Flow Unit
Cleanroom 1
Cleanroom 2

9. Cryostat Insert Stand – Mock-up
Laminar Flow Unit
The mock stand has been built to determine
a final working solution for the cryostat inserts
and to develop a suitable cleanroom facility for
the required operations.
The mock stand has enabled the team to:
Visualise the physical size and location of the
structure.
Determine the working height & position
of the cavities, including testing the loading and
unloading of cavities – including safe
manoeuvrability of the cavity and clearance
for the lifters.
Design a cleanroom facility to meet ISO
standards for the connection of the UHV lines.
Determine processes and procedures.
Changing room
Cleanroom 1

10. Full Cleanroom Solution – Under test
The cleanroom enclosure has been designed
and built around the mock cryostat insert stand
structure. Materials and equipment were
sourced from previous projects, including:
Anti-static perspex screens and seals.
The main ULPA filtration fan unit.
The floor has been cleaned but not sealed.
Particle counts where taken at points 1 – 6.
10 x 1 minute air sampling taken at each position
for 1m3
Points 1- 3 at cavity height 26” from the filter.
Points behind the UHV valve connection 1 4
Cavity 1
ISO 3
ISO 3 2 5
Cavity 2
ISO 3
ISO 3 3 6
Cavity 3
ISO 4
ISO 5
Laminar Flow Unit
Best result: ISO 3 at rest
Cleanroom 1

11. Solution 2: Glovebox The Glovebox solution has been designed to:
Reduce the size of the cleanroom.
Speed up the process, minimising
cleaning of the cavity and
infrastructure – reduced manpower.
Eliminate the changing area and
full gowning procedures.
User friendly solution for enclosure/
isolation of the cavities.
Reduce overall costs.
Fixed particle counter monitoring for
each cavity – quality control.
Cavity 1
ISO 3 1
Cavity 2
ISO 3 2
Cavity 3 3
ISO 5
Laminar Flow Unit
Best result: ISO 3 at rest
Glovebox

12. Modular Cleanroom ISO 5 personnel Area and ISO 4 Isolator
Seals around Cavity Flange
Fixed particle monitoring for QA.
Processes and procedures to be determined for UHV connection
*Modelling performed by Connect 2 Cleanrooms

13. Modular Cleanroom

14. Cryostat Insert Stands
Image 11/09/17

15. SPSV System
System is fully automated except for manual cavity isolation valve
RGA is used to check vacuum line (~10-7 mbar and leak rate ≤ mbar∙l∙s-1 ) before cavity isolation valve is opened
All cavities are expected to arrive under vacuum however system is designed so that it can tolerate an unforeseen high cavity pressure
System allows both controlled venting and pumping using MFC’s
Active pumping is stopped at approximately 70 K; system is then cryo-pumped.
RGA monitors the cavity during cryopumping
Active pumping re-started once RF test is complete and warm up begins
Also Used for Quality Control/Acceptance test.

16. KEY: Backing Pump 1 Backing Pump 2 Backing Pump 3 N2 MFC N2 MFC N2 MFC
PFV – Power Fail Valve
L – Line
V – Valve
P – Pirani Gauge
PRD – Pressure Relief Device
FR – Full Range Gauge
RGA – Residual Gas Analyser
MFC – Mass Flow Controller
SV – Separation Valve
– Represents flow direction of MFC
Backing
Pump 1
Backing
Pump 2
Backing
Pump 3
L1V1
L2V1
L3V1
L1P1
L2P1
L3P1
L1P2
L2P2
L3P2
PFV1
PFV2
PFV3 N2
MFC N2
MFC N2
MFC
L1P3
L2P3
L3P3
L1V3
Turbo 1
300 l/s
L2V3
Turbo 2
300 l/s
L3V3
Turbo 3
300 l/s
L1V2
L2V2
L3V2
L1P4
L2P4
L3P4
MFC
MFC
MFC
L1P6
L1CC1
L2P6
L2CC1
L3P6
L3CC1
L1P5
L2P5
L3P5
L1V5
L2V5
L3V5
L1CC2
L2CC2
L3CC2
L1V4
L2V4
L3V4
L1PRD1
L2PRD1
L3PRD1
L1P7
L2P7
L3P7
L1V6
L2V6
L3V6
SV1
SV2
L1PRD2
L2PRD2
L3PRD2
L1CC3
L2CC3
L3CC3
L1P8
L2P8
L3P8
L1 RGA1
L2 RGA1
L3 RGA1
L1V7
L2V7
L3V7
L1P9
L1CC4
L2P9
L2CC4
L3P9
L3CC4
CRYOSTAT TOP FLANGE

17. Discussion Main driver for transporting under vacuum?
Acceptance criteria 10-4 mbar?
To what standard have the SPSV systems been validated, including the UHV lines?
Procedure if we have failures – full clean and particle count?
RGA monitoring during testing?

18. Thanks to the ESS High Beta team
Louis Bizel-Bizellot
Phil R Davies
Mike Ellis
Philippe Goudket
Ed Jordan
Tom Jones
Keith Middleman
Peter McIntosh
Shrikant Pattalwar
Mark Pendleton
Phill Smith
Stuart Wilde