1. Medium beta cryomodule demonstrator M-ECCTD
P. Bosland - TB23 - Lund - 7 Sept 2017

2. performances of the 4 Cavities mounted in the M-ECCTD tested in vertical cryostat
3 CEA cavities
1 LASA cavity
Performances limited by e- field emission

3. Power coupler RF conditionning
1.2 MW peak
8 couplers conditioned at full power in travelling wave and reflected power (Emax and Bmax at the ceramic window)
4 mounted on the M-ECCTD
1 on cavity Hbeta sent to Uppsala
2 Hbeta for the H-ECCTD
1 spare conditioned …
2 last couplers to be conditioned later for the H-ECCTD

4. M-ECCTD Cryomodule clean room assembly
March 2017
Jan. 2017
performed in the ISO4 Saclay clean room
Nitrogen venting during assembly process
XFEL type aluminium gaskets
Cavities pre-aligned
Cavity string under vacuum before rolling out of the clean room

5. Cavity string dressing
April 2017
Welding of the titanium diphasic line
Assembly of the MLI, magnetic shields, cold tuners and cryogenic piping

6. Cavity string insertion inside the spaceframe
May 2017
Thermal shield preliminary prepared with MLI and instrumentation, and fixed on the spaceframe

7. Cavity string Mass supported by the spaceframe
June 2017
Assembly of the cavity tie rods
Cavity alignment
The clean room cavity posts can be removed

8. Spaceframe insertion inside the vacuum vessel
July 2017
Jumper connection assembly
cryogenic connections at the cryomodule extremities
Leak check of all the cryogenic circuits

9. Cryomodule installed inside the test station at Saclay
Last assembly operations: atmospheric compensation system on coupler flanges, doorknob transitions
Beam line vacuum pumping
Instrumentation cabling, cryogenic and waveguide connections

10. First cooldown after the installation in the test stand
Short summary of the tests already done during the period of 22 to 30 August
First cooldown after the installation in the test stand

11. Warming up with 100mbar GHe in vacuum vessel
2 days at 4K and ~2K (?)
Beam vacuum
Thermal shield T
Diphasic tube T (cavity)
Tuner T
Warming up
Cool down at 4.2 K
Pumping on LHe bath
Warming up with 100mbar GHe in vacuum vessel
Shutdown racks
(Electrical leaks GHe heat exchanger)
Shutdown compressed air
(Saclay center)
Break of a coupler ceramic
(doorknob assembly)

12. Temperature on diphasic tube (cavity)
Pumping on the LHe bath
LHe at 4.2 K
Pressure in diphasic line
Pumping on LHe bath down to 27mbars
Shutdown of the electrical supply of the control system
Shutdown of the compressed air (and He liquefier)
Temperature on diphasic tube (cavity)

13. Mounting the doorknobs (Cavities at room temperature and under vacuum)
Fans for the cooling of the cover
Fans for the cooling of the test box bottom
Test box
Coupler 1
Coupler 2
Previous experience:
About 15 assemblies of doorknobs for the conditioning of couplers (top-down assembly)
Assembly of the 4 doorknobs on the cryomodules is bottom-up
The “final” tooling was not ready
(nor the assembly procedure !)
The assembly of the 1st & 2nd doorknobs was done without any issue with a rough tooling

14. The 3rd ceramic window broke during the doorknob assembly (Thursday the 31st August)
Screws of the ext conductor were unscrewed in order to allow alignment of the doorknob flange with the wave guides (there is a rotable flange)
The external conductor and inner conductor of the doorknob were not coaxial
When the doorknob was elevated, it was guided with the flange of the external conductor
The inner conductor of the doorknob pushed the inner conductor of the ceramic window
The ceramic exploded
The violent venting of the cavities transported some ceramics parts inside the cavities
It is a human error.
The operator was alone (These operations have been usually being done by two operators). Two Persons of the engineering office were present for getting information about the design of the tooling they are in charge of (the operator has been disturbed and forgot to screw the bolts of the flanges !)

15. Consequences on the short term plan
The cavity vacuum was violently refilled with dirty air and ceramic parts.
Cavities and couplers are now polluted.
No RF power test can be performed.
The broken coupler has been removed and cavity vacuum closed with a blank flange
The cavity vacuum has been pumped
Cryogenic tests and tests of the piezo tuners with low level RF tests can still be performed.
The cryomodule is now cold and tests are on going
Friday 1st Sept: start of the thermal shield cool down
Monday 4th : start of LHe filling (at 4K).
Tests of the tuner (motor and piezo)
First cavity tuned at 4K and MHz
Expected duration of the tests 2 to 3 weeks

16. mid term plan is being established and presented to ESS next week
Our driving features:
M-ECCTD will be dismounted, remounted and tested at high power at Saclay as soon as possible before the H-ECCTD.
The plan for reprocessing of the cavities is being established. The objective is to minimize the time. The reprocessing of cavities is the driving time of the planning.
LASA cavity needs to be prepared again. A meeting shall be organized with the LASA team to discussed all the details of this preparation (next week ?) .
The 3 remaining couplers will be reprocessed with the spare one
The cryomodule will be assembled with the new updated toolings (and the tooling for the doorknob assembly!)
A review of our toolings can be organized before the CDR for the assembly of the series.
Before the tests of the complete M-ECCTD (beginning of next year), the tests at Uppsala of a high beta cavity will be complementary to the present test of the damaged M-ECCTD at Saclay.
As we have no spare coupler we want to limit the max power on the coupler at 1.1MW peak during the tests in Uppsala (tests at higher power shall be done later)

17. We don’t modify the procurement plan for the series
But CDR2 will be delayed
CDR2 is milestone for some contracts for production release.
Analysis of the consequences is in progress

18. Other topics (monthly report sent by Franck yesterday)
Prototype H-beta cavity P02
100 µm BCP in September followed by a test in vertical cryostat
Medium beta cavities:
P06 cavity is at ZANON: heat treatment and clean room preparation. The shipment of the cavity to CEA is scheduled week 37. Test in vertical cryostat will be done at Saclay before the integration of the tank.
Five high beta cavities fabricated at RI:
RF measurements of half cells are finished.
Welding of the first dumbbells and endgroups (for cavity #1) will be done in the coming weeks.
H-beta prototype cavity ESS086-P01 equipped with a coupler has been sent to Uppsala.
A first pair of high beta couplers has been conditioned in August. The polarization system have been successfully tested for the first time.

19. Other topics (monthly report sent by Franck yesterday)
RF Power conditioning station for power couplers:
Installation of the THALES RF power source is on-going.
Klystron, circulator and two waveguide loads installed
The cooling system with a cooling skid and a hydraulic distribution line installed
Two racks (Electrical distribution and control/command ).
High voltage modulator: acceptance tests on a dry load planned in November.
The Klystron
Circulator
Two waveguide loads
Control racks

20. Other topics (monthly report sent by Franck yesterday)
The modulator area
Electrical distribution rack
Installation of the cooling skid for the 704 MHz RF power source

21. Status of the procurements
Call for candidates
Call for tender
Vacuum vessels
done
Contract awarded to ACPP
Power couplers
Contract awarded to PMB, manufacturing drawings under validation
Coupling boxes for coupler conditioning -
Contract awarded to SDMS, kick-off done in May
Thermal shieldings
 Contract awarded to SDMS, kick off meeting done in April
Spaceframe
Contract awarded to SDMS, kick off meeting done in May
Cold Tuning Systems (mechanical part)
 Supplier chosen, kick-off meeting planned in September
Motors for cold tuning systems
Contract awarded, 12 motors received
Cryogenic heat exchanger
Offers received, analysis in progress
Magnetic shielding
Supplier chosen, kick-off meeting planned in September
MLI
Done
Call for tender launched
Internal instrumentation
Supplier chosen, order in progress
Intercavity bellows, cold-warm transitions
Cryogenic circuits, diphasic tubes, coupler bells
In stand by
Cryogenic valves CV01 and CV02
Cryomodule assembly
Applications received, analyses in progress

22. Last results (~12H today)

23. Thank you
Commissariat à l’énergie atomique et aux énergies alternatives
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