1. XFEL Cold mass & vacuum vessel non-conformities Detected At saclay
2015
XFEL Cold mass & vacuum vessel non-conformities Detected At saclay
WG cryomodule TTC SLAC / Thierry Trublet – CEA Saclay

2. 72 cryomodules have been delivered up until now
Introduction
In the context of the XFEL project, CEA is in charge of assembling the 100 linac cryomodules
72 cryomodules have been delivered up until now
The XM100 will be delivered at the end of April 2016
CEA has contracted with ALSYOM for assembly
DESY provides cold mass & vacuum vessels
44 out of 45 delivered by ZANON
32 out of 55 delivered by IHEP
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

3. Deliveries
Cold mass & vacuum Vessels are delivered separately (the cold mass is not delivered inside the vacuum vessel as planned at the beginning)
The hardware and 8K/70K shields are delivered one week before cold mass for preparation
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

4. Non-conformities detected at Saclay
We have been faced with several types of non-conformity and they are recurrent mainly on hardware, shields and cold mass.
The cold mass is a complex manufactured component and requires careful inspection during the fabrication process.
Parts were frequently missing on the hardware (true for all parts of the cryomodule)
Most of the non-conformities led to additional work at Saclay (repair, rework, replacement).
Only 1 cold mass and 1 vacuum vessel were returned for repair to DESY
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

5. Main non-Conformities
Main non-conformities on cold mass / Vacuum vessel 4K-70K shields / Hardware
Picture
Main non-Conformities
Provider p6
GRP (Gas Return Pipe) bent
IHEP
Cold mass p7
Diameter of GRP oval or too large
IHEP ZANON p8
4K superinsulation eaten by mice p9
Hole for locating pin not deep enough
IHEP 
p10
4K superinsulation was mounted on right side or left side of the ZANON cold mass
ZANON
p11
Weld bead prevents assembly of washer and screws for fastening the needle support - Cavity support frame
p12
The surface for fitting the big flange was too rough
ZANON 
p13
Paint and dirt inside threaded holes on several ZANON and IHEP vacuum vessels.
 ZANON
Vacuum vessel
p14
The shape of the 70K was non-conform on several ZANON 70K shields and a few IHEP shields
 IHEP
p15
8K Coupler Copper braids were too short (IHEP)
70K shield
XFEL cold mass & vacuum vessel non-conformities detected at Saclay– TTC SLAC

6. Main Cold mass non-conformitIES
GRP bent
GRP (Gas Return Pipe) bent
Invar rod & clamps
Cavity string
The GRP on IHEP cold mass was bent (on 4 CMs)
Consequence: the pin on certain cavities is in contact with the invar rod clamp
The clamps have been reworked
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

7. Main Cold mass non-conformitIES
Diameter of GRP oval or too large
The GRP diameter on IHEP cold mass was oval (on 2 CMs)
Consequence: the mandrels could not be installed in the GRP
New modified mandrels have been sent by DESY
Mandrels positioned in the GRP
The diameter of GRP on ZANON cold mass was too large (on 2 CMs)
Consequence: the mandrels cannot be fastened in the GRP
Aluminium sheet has been placed between GRP and mandrels
End cap clamped in the mandrels
and on the vacuum vessel
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

8. Main Cold mass non-conformitIES
4K superinsulation eaten by mice on IHEP cold mass (on 2 CMs)
The superinsulation has been repaired
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

9. Main Cold Mass non-conformitIES
Locating pin loose in the posts on IHEP Vacuum vessel (wrong pin hole dimension)
Risk: the alignment reference for cavity positioning could change after dismantling/mounting the posts
CX015 will be sent back to DESY for repair
CX023 will be used as is because 1 in 2 pins is clamped correctly and the locating defect is acceptable
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

10. Main Cold mass non-conformitIES
4K superinsulation was mounted on right side or left side of the ZANON cold mass
Consequence: 2 different assembly procedures were therefore required (cutting holes for couplers is easier if the superinsulation is mounted and rolled to the coupler side)
Hole for coupler
coupler
4K superinsulation rolled on coupler side
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

11. Main Cold mass non-conformitIES
Weld bead prevents assembly of washer and screw for fastening the needle support - Cavity support frame (on ZANON and IHEP cold mass)
Solution: the washer is removed or we grind the weld
needle support
Cavity string hanging via
needle bearings
Cavity support frame
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

12. Main Vacuum Vessel non-conformitIES
The surface for fitting the “big flange” was too rough. The marks of the milling tool were visible on at least 4 ZANON vacuum vessels
Solution: The surfaces were re-machined by DESY at Saclay
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

13. Main Vacuum Vessel non-conformitIES
Paint and dirt inside threaded holes on several ZANON and IHEP vacuum vessels.
Solution: the threaded holes are re-worked and cleaned by operators
Clean room assembly process VS XFEL cryomodule performances – TTC SLAC

14. 70K shields non-conformity
The shape of the 70K was non-conform on several ZANON 70K shields and a few IHEP shields
Consequence: The 70K interface of the coupler touched the shield when the coupler antenna was moved
Solution: the shields were cut to enlarge the passage
Before
After
XFEL cold mass & vacuum vessel non-conformities detected at Saclay – TTC SLAC

15. Non-conformity on the Hardware
8K Coupler Copper braids were too short (IHEP)
Consequence: Copper braids were replaced
XFEL cold mass & vacuum vessel non-conformities detected at Saclay– TTC SLAC

16. Production des cryomodules XFEL - Journées AFF-CSS @ Aussois 2015
Commissariat à l’énergie atomique et aux énergies alternatives
Centre de Saclay | Gif-sur-Yvette Cedex
T. +33 (0) xx xx | F. +33 (0)
Etablissement public à caractère industriel et commercial | RCS Paris B
DSM Irfu DIR
Production des cryomodules XFEL - Journées Aussois 2015