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

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

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

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

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

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

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

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

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

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

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)

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)

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

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 !)

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 704.42MHz Expected duration of the tests 2 to 3 weeks

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)

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

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.

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

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

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

Last results (~12H today)

Thank you Commissariat à l’énergie atomique et aux énergies alternatives Centre de Saclay | 91191 Gif-sur-Yvette Cedex T. +33 (0)1 69 08 76 11 | F. +33 (0)1 69 08 30 24 Etablissement public à caractère industriel et commercial | RCS Paris B 775 685 019