1. Elliptical cryomodules
Annual audit for WP5
Elliptical cryomodules
P. Bosland
1st prototype cryomodule M-ECCTD
2nd prototype cryomodule H-ECCTD
9 medium beta serial CM cavities
21 high beta serial CM cavities

2. Two prototype cryomodules
M-ECCTD with medium beta cavities – 2016
FR-SW agreement
Collaboration IPNO and IRFU
H-ECCTD with high beta cavities – 2017
French In-kind contribution

3. FR – SW agreement + amendment
Collaboration IRFU – IPNO
P. Bosland WPL5 - G. Olivier
Christine Darve
FR – SW agreement + amendment
IPNO in charge of the cryostat – design and fabrication
Vacuum vessel
Space frame – cavity supports
Thermal screen
Superinsulation
Internal cryogenic pipes
Instrumentation
IRFU in charge of the “cavity package”, the cryomodule assembly and RF power tests:
Cavities + helium tank
Power coupler design, manufacturing, RF tests
Piezo tuner
Magnetic shield
Tooling: field flatness, cavity preparation, cryomodule assembling, …
Cryomodule assembly
Tests stand for cryogenic and RF power tests
Tests of the ECCTD cryomodule

4. Cryomodule Design
Similar to CEBAF/SNS cryomodule with 4 cavities per cryomodule
Common design for medium (6 cells) and high beta (5 cells) cavity cryomodules
Accelerating gradient:
for b=0.67 (Medium Beta): Eacc=16.7 MV/m Qo> 5E9 at 2 K
for b=0.86 (High Beta): Eacc=19.9 MV/m Qo> 5E9 at 2 K
Maximum operating helium pressure: bar
total length: 6.6 m
Beam height: 1.5 m

5. Medium / High beta cavity
Tank (Ti)
Magnetic shielding
Cold tuning system
Medium
High
Geometrical beta
0.67
0.86
Frequency (MHz)
704.42
Operating temperature (K) 2
Maximum surface field in operation (MV/m) 45
Nominal Accelerating gradient (MV/m)
16.7
19.9
Nominal Accelerating Voltage (MV)
14,3
18,2
Q0 at nominal gradient
> 5e9
Cavity dynamic heat load (W)
4,9
6,5
Qext
High beta (0,86):
5 cells
Length 1316,91mm
Medium beta (0,67):
6 cells
Length 1259,40mm
57,5 mm
Medium
High
Iris diameter (mm) 94
120
Cell to cell coupling k (%)
1.22
1.8
p and 5p/6 (or 4p/5) mode separation (MHz)
0.54
1.2
Epk/Eacc
2.36
2.2
Bpk/Eacc (mT/(MV/m))
4.79
4.3
Maximum. r/Q (W)
394
477
Optimum b
0.705
0.92
G (W)
196.63
241
No HOM couplers
HOM frequencies must be carefully controlled

6. HOMs
This HOMs have been found at and MHz (P01) and and MHZ (P02) => 3D measurements of the ½ cells and end groups required for the production of next medium beta cavities Stiffening ring on the external ½ cell ?

7. Experience of the HIPPI power coupler at Saclay
HIPPI power coupler (KEK-type window) tested to 1.2 MW, 10% Duty factor at Saclay
Test of the HIPPI power coupler on the HIPPI cavity at 1.8 K, full reflection

8. The ESS power coupler
Pmax = 1.2 MW peak at 4 % duty cycle → critical component
RF disc ceramic window
Inner conductor
Conical tip for stronger coupling
Water cooling
Outer conductor
Cooled with Liquid He in the vac. Vessel
Coax to rectangular RF transition (Door Knob)
HV bias with RF trap
CM integration
Large diameter flange with below on vacuum vessel
3 diagnostic ports
New design of the doorknob waveguide transition including a HV bias capacitor with RF trap
Coupler conditioning set-up

9. Cold tuning system Type V for SPL beta = 1 5-cell prototype
Saclay V type adapted for ESS cavities
+/- 3 mm range
1+1 piezo
Cold motor and planetary gearbox (1/100e)
Piezo support has a stiffness 10 times higher than the cavity  piezo preload at 2K is independant of the cavity springback force
Type V for SPL beta = 1 5-cell prototype
CTS linearity at 4.2K of type V-HIPPI

10. Magnetic shield
Limit contribution of the trapped flux to the surface resistance to 4nW
Limit the external static field to Bext = 14 mG.
→ required shielding efficiency equal to 35.
Requirements achievable with a 2 mm in thickness and mr=15000 shielding material

11. Supports of the different cold components
Blocking nut
Cross rods fixed on 2 titanium half rings fastened to the helium tank on one side and on the spaceframe on the other side
3000N pre-stress applied on the rods, maximum force 8500N per rod after cooling down
Pre-stress nut
Rods (TA6V, Diam. 6mm)
Magnetic
shield
Half rings linked to the tank (under the magnetic shield)
Rod
Thermal shield
3 jacks at 120° supporting the spaceframe after insertion
2 wheels fixed to the spaceframe at each extremity
Guiding ensured by two rails welded to the vacuum vessel
Supporting rods
Special boxes allowing the axial moving and the thermalization of the thermal shield

12. Inter-cavities bellows
Mechanical cavity misalignment on the cavity strings
Longitudinal shrinkage of the cavities
Thermal isolation at the two extremities of the cryomodule
Cold to warm transition
MEDIUM BETA
Number of corrugations: 10
Overall length 240,5mm
Axial stiffness for 10 corrugations 21N/mm
Radial stroke for 10 corrugations +/-0.80mm
Radial stiffness for 10 corrugations 4450N/mm
HIGH BETA
Number of corrugations: 6
Overall length 183mm (at rest)
Axial stiffness for 6 corrugations 35N/mm
Radial stroke for 6 corrugations +/-0.48mm
Radial stiffness for 6 corrugations 7417N/mm
Distribution of the RF HOM modes

13. Spaceframe Spaceframe: Aluminium alloy
Forces on Rods: 3000 to 9000N
Mass spaceframe: Kg
Total mass of cavities + thermal shielding: 1200Kg
Blocking by 3 jacks on two levels
Tuning (3 positions)
Spaceframe:
Aluminium alloy
Lower part can be disassembled to insert the couplers
Depl. Total
(mm)
Depl. Struct.
Depl. Blocs
Contrainte max (Mpa)
1,32
1,24
(Z: -1,21 à +0,50)
0,12 à 1,08
(Z: -0,89 à +0,18) 30

14. Access traps blocking of the cavities and spaceframe during transport
Access in the tunnel
Maintenance of cold tuning system (change motor and piezo)

15. Alignement of the cavities Alignment made by laser tracker
Beam axis reported to reflector bracket on beam flanges 1 2
Alignment of the cavity string within 1,5 mm of the beam axis 3
Vessel alignment with respect to cavity string 4
Alignment made by laser tracker
Reflector brackets
(vessel alignment)
Alignment of the cryomodule in the tunnel (source ESS)
Reflector brackets
(coupler flange)
Reflector brackets
(cavity flange)
1,5" Corner cube reflector
Additional fiducials will be set up inside the ECCTD cryomodule to check the alignment after cooling down.

16. Heat loads
Values in Watts

17. PID for the elliptical cryomodules

18. Instrumentation list for the M-ECCTD……

19. Compliance with the PED
97/23/EC
Relative pressure
Vessels
Pipes
50 L
Elliptical cavity
1 bar
PS<0,5bar:
The equipment is not on the scope of the 97/23/CE directive
Article 3.3
The equipment must be designed and manufactured according to workmanlike way
Category I
The manufacturing must be more documented, especially with internal production control
Objective: stay within « Article 3.3 » area

20. Helium Pressure relief devices
Cavity pressure test
1,43 PS
Working pressure = nominal pressure WP
PSET Set Pressure PS
Maximum allowable overpressure
PS + 10%
Safety devices
Safety devices
2,72 bar
2,09 bar
Bursting disks
+/- 10%
Absolute pressure
Max. allowable press.
PSET + 10%
1,9 bar
1,891 bar
Bursting disk
1,81 bar
Bursting area
PSET – 10%
European rules compliance Article 3.3
1,729 bar
Safety margin
PSET
POPENING = + 5 % PSET
(overpressure when opening)
PMAX APERTURE = + 10 % POPENING
PCLOSING = - 5 % PSET
PMIN CLOSING = - 10 % PCLOSING
(hysteresis before closing)
59mbar
1,670 bar
1,609 bar
Relief valve
MAWP 1,58bar
Opening area
1,551 bar
1,496 bar
Safety margin
1,431 bar
(1,3 +10%)
65mbar
WP upper limit
1,301 bar
ESS Helium factory, circuits
and operating modes

21. Helium low pressure circuit
2 bursting disk at each tip
+ upstream safety relief valve (with he guard)
To valve box
A 36° angle is set up for the tank nozzle in order to allow the insertion of the cavity string and the cooling circuit inside the spaceframe
Heat exchanger
36°
The circuit is designed to reduce as low as possible the overpressure in case of beam vacuum failure by using a continuous DN100 diameter for the diphasic pipe, large curvatures and 2 DN100 bursting disks at each extremity.
Worst scenario: beam vacuum failure
38KW/m2 heat load on the cavity wall
Accidental overpressure: 230mbar after rupture of the disks

22. Cryomodule assembly

23. M-ECCTD Two objectives: To qualify the technology
To prepare the assembly procedures, the tools and the documentation for the serial elliptical cavity cryomodules
Assembly procedure
Assembly procedure
Integration tools
Integration tools
Items
manufacturing
ECCTD
integration
Ready for the serial cryomodules
Documentation
Documentation
Others
Others
Preliminary Version
Final Version

24. Analyse of the assembling sequence
Student: Amaury Martin 09/2013 – 01/2014
Study of the assembling sequence and needs of toolings
Assembling in clean room
Assembling outside clean room
Pre-study of the toolings: compatible with both types of cavities medium and high beta

25. Coupler / cavity assembly
State of the art: interface coupler / cavity parallel to the laminar air flow
Horizontal coupler
Rotation needed after assembly to get to the final vertical position of the coupler in the cryomodule
Complex tooling
First rough analysis of the air flow around the flange: the air flow may be pertubated because of the reinforcement sheets of the helium tank
Choice: vertical assembly
Tooling compatible for both types types of cavities
Adjustment of the coupler position relative to the cavity flange
Coupler vertical
Coupler horizontal
Air speed
Whirlwind

26. Frame and supports for the assembly in clean room

27. Cavity string assembly in clean room
Design still in progress
Beam axis height: 1150 mm from the clean room ground
Individual position adjustment system of each cavity and bellow
Supports of the cold to warm transition bellows to be designed

28. Assembly outside clean room
Thermal screen installed but not shown
Wheels on the spaceframe
Guiding rail on the vacuum tank

29. Courtesy of Catherine MADEC - XFEL
. The implementation of the assembling process at Saclay will be based on the SPIRAL2 and XFEL experience
Courtesy of Spiral 2 CEA team
Courtesy of Catherine MADEC - XFEL

30. Short status of the M-ECCTD
Cavities:
Medium beta: fabrication started ‘6 cavities ordered to ZANON)
Couplers:
RF window and antenna ordered (8 ceramic windows ordered to Toshiba)
Call for tender for outer conductor (double wall) and door-knob
Tuners, magnetic shielding:
Design 95% finalized
Fabrication to be launched
Spaceframe, vacuum vessel:
Design finalized. Preparation of the procurement procedures in progress
(goal: launch the procurement before the end of January 2015)
Test stand: modification of the cryogenic line and HV modulator in progress
Clean room assembly toolings: studies started - still in progress

31. Two high beta prototype cavities manufactured
Results of the first tests in vertical cryostat
P01 ESS
Prototype high beta cavity manufactured by ZANON
P02 ESS
Prototype high beta cavity manufactured by RI
Heat treatment to remove hydrogen performed at CERN last week
Next tests in VC mid of November

32. Planning of the M-ECCTD and H-ECCTD
Goal: qualification of the cavities/coupler
And launch of the cavities and couplers production in Sept 2016

33. Schedule of the WP5 activities

34. Recommendations of the last audit at Orsay the 28 10 2014
Appendix B – Recommendations
1) Review decision and resulting design for limiting pressure for PED Cat 0
The auditors recommend WP4,WP5 review its decision to design to 0.5 bar gauge for avoiding PED Cat I+ certification requirements.
WP4/WP5 should:
Seek an independent peer review of the pressure safety design. Consider the possibility of 2 phase helium flow at the relief valves
Start early discussions with a certifying organization for all implications such as raw material certification, traceability, safety analysis, etc.
Review decision regarding 0.5 bar gauge and design resulting from this decision. Review operational implications of such a design
Include in the time schedule activities for certification of crymodule pressure vessels. Includes QA traceability of materials.
Ps = 0.9 bar article 3.3 of PED
2) Amend requirement: ESS-SYR-ACC-SPKL-EMR 190 Cavity RF instrument sensitivity – change from 1 V to ? - ESS – S. Molloy
3)Determine who the appropriate pressure certifying agency shall be for these cryomodules Responsible: ESS – J. Weisend II
4) Review design for active cooling for magnetic shielding: Solution for elliptical cryomodules is different and simpler. A single solution for all cryomodules shall be sought - IPNO
5) Develop requirements for cryomodule mounting and interface with ground
ESS – S. Molloy and C.Darve

35. In progress Done Done Done
6) Amend ESS-SYR-ACC-SPKL-EMR 210 to include tolerances ( ?) Add requirement for yaw (rotation)
ESS – S. Molloy and C.Darve
7) Develop Level 4 requirements for Vacuum for WP4 and WP5. This includes creating requirements for cryomodules interface to isolation vacuum system including:
size of the port
flange design
pumping capacity
define normal modes and maintenance mode and hence resulting configurations e.g. opened / closed valves
vent requirements
use of portable pump cart
ESS – S. Molloy and C.Darve, with input from P.Ladd (WP12)
In progress
8) Generate Heat Load requirements to WP11 for all cryomodule types. Requirements should be given by temperature level (2 K, 40 K and 4.5 K) and given for both static and dynamic cases.
This is required by the end of 2013, to enable tendering for cryoplant during 2014.
ESS – S. Molloy, C.Darve, and P.Arnold (WP11)
9) Generate Level 4 requirements between all accelerator types and WP11 Cryogenics.
Examples of needed requirements include
Definitions of cryomodule failure modes and expected responses
Operation modes (reference existing document)
Interfaces e.g. WP11 responsibility starts at vacuum barrier on cryosystem
10) Provide a tech note of calculations to ESS, to explain static and dynamic heat loading and to justify design choices for Spoke & Elliptical cryomodules.
IPNO and CEA Saclay
11) Create Cryogenic Standards Document for ESS
ESS –P.Arnold (WP11)
Done
Done
Done

36. 12) Determine and document the minimum wait time before entering tunnel after beam operations.
ESS - D. McGinnis
13) Develop a requirement for the warm-up time for both the Spoke and Elliptical cryomodules
ESS – S. Molloy, C.Darve, and P.Arnold (WP11)
14) Review design of seals
Reconsider use of VCR, swagelock connectors with metallic seals and replace with welds wherever possible
IPNO and CEA Saclay
15) Review pressure relief system design to ensure that the burst disc reliefs are only used for catastrophic events and that the spring loaded relief valves are used in all other cases (power failure, cryoplant shut down, improperly operated controls valves etc)
Done
16) Finalize P&ID’s for elliptical and spoke cryomodules.
ESS – S. Molloy, C.Darve, P.Arnold (WP11) and agree interfaces with CEA Saclay
17) Ensure drop plate or other pressure relief devices in the cryomodule vacuum chamber is shown on the P&IDs
IPNO and CEA Saclay
18) Review the planning of activities for the series –production elliptical cryomodules to ensure that it is not overly optimistic. Ensure that any updates are added to the ESS Integrated Project Schedule (P6)
CEA Saclay and ESS (C.Darve)
19) Develop Level 3 or Level 4 requirements for the ICS interfaces for all resonators (RFQ, DTL, Spks, Ellipticals etc), in regards to PLCs, PLC programming, MPS (Machine Protection System) and PSS (Personnel Safety System). Ensure assignment of responsibilities are clear
ESS – A. Ponton (WP3), S. Molloy, C. Darve and G.Trahern (ICS)
Done
Done
Done

37. The transport has to be organized by ESS
20) Identify responsibilities for transportation of cryomodules between IPNO-Uppsala and between CEA Saclay- and ESS and document these in the WP descriptions, IKC agreements and contracts. Note that it may be necessary to develop transport-related performance requirements at Level 4 or 5 e.g. lifting eyes, vibration limits, drop test criteria, waterproofing, corrosion resistance etc.
ESS - S. Molloy and C. Darve, IPNO and CEA – Saclay
21) Review the design and verify with the certifying organization the joints between Niobium and Tinanium without NiobiumTitanium alloy parts. Same investigation for the high temperature (600 °C for de-hydrogenation) treatment of cavities already welded in the titanium Helium tank and with already welded Ti Gr5 bellow (max temperature for Ti parts).
The transport has to be organized by ESS
Specification for the transport written by CEA with the agreement of ESS.
Should not be an issue if the cryomodule stays in Article 3.3

38. Thank you for your attention

39. The team for the ECCTD changes New teams are being buit for the WPs
IRFU is preparing the new organization of the project for the CEA In Kind contribution
The team for the ECCTD changes
New teams are being buit for the WPs
Example of the WP for the ECCTD WU
Assemblage
Intégration
RWU
C. Madec
Coupleurs
C. Arcambal
Outillages
N. Bazin
J.P. Poupeau
Blindages
magnétiques,
Expertise
J. Plouin
Tuners
G. Devanz
Cryostat
G. Olivier
CNRS/IPNO
Cavités
F Peauger
Test
F. Peauger
Instrumentation
interne
Workpackage
ECCTD
RWP: F. Peauger
Qualité
A. Bruniquel
Planning
X. Hanus
Responsable
Scientifique
Ingénieur
Système
Bunker test
704 MHz
J.P. Charrier
Cryomodules
O. Piquet
Système de
Contrôle
F. Gougnaud
Source RF
A Hamdi
Cryogénie
P. Sahuquet
B. Renard
Processing
A. hamdi
Suivi industriel
V. Hennion
N. Berton
P. Contrepois
Bureau d’études
P. Hardy
F. Leseigneur
Infrastructure
de test