Accelerator/Elliptical Cavities Cryomodules Pierre BOSLAND, CEA Saclay External WP5 leader Christine Darve, ESS deputy WP leader April,

Elliptical Cryomodules Overview Proton Beam Elliptical cavities Cryomodules Medium-  and high-  2

3 Proton Beam Production & test of the cavities of the series (LASA & STFC) Acceptance RF power tests of the cryomodules (ESS Lund) Design of the Cryostat of the cryomodule made in collaboration of CEA- IPN Orsay G. Olivier LASA proposes a new design of the Medium beta cavity different from the one developed by CEA during the prototyping phase CEA is in charge of the whole activity for the prototyping and the production of the 30 M & H beta cryomodules except => Not in the scope of CEA: Elliptical Cryomodules Overview

4 Schedule Hold point Release of Hbeta component production Very ambitious planning compliant with the RFI (Ready For Installation) dates of the cryomodules

5 Technical performances The level-4 requirements for the medium and high beta cryomodules are listed in the DOORS management system (Dynamic Object-Oriented Requirements System) Selected requirements: Frequency: 704,42 MHz Nb superconducting cavities at 2K: medium beta cavities: 6 cell at  geo =0,67 high beta cavities:5 cell at  geo =0,86 Nominal accelerating gradients Eacc corresponding to 45MV/m peak field :  16,7MV/m : medium beta cavities  19,9MV/m : high beta cavities Max RF power dissipation at nominal gradient corresponding to Q 0 = (Cryo. duty cycle: 4,7%): – Medium beta cavities:4,9W – High beta cavities:6,5W Maximum RF peak power: 1,1MW No HOM coupler: All higher order modes (HOMs) shall be at least 5 MHz away from integer multiples of the beam-bunching frequency ( MHz) for any HOMs whose resonant frequencies are below the cut-off frequency of the beam-pipe.”

6 Technical performances – Example : H- ECCTD

7 Selected technologies Segmented cryomodules 6,6 m long - beam gate valves 4 cavities Power couplers located below the cavities Space frame holding the cavity string Superconducting elliptical cavities : Bulk niobium Stiff cavities to reduce the Lorentz force detuning No HOM couplers RF power coupler: HIPPI type coupler tested up to 1,2MW at 10% DC and pulse length of 2ms New door knob equiped with a bias system and RF trap Tuner HIPPI tuner modified with a second piezo stack for reliability improvement

Selected technologies 8 Common design for medium (6 cells) and high beta (5 cells) cavities Proton Beam Jumper connection Cold to warm transition Magnetic shielding Power coupler Cavity with Helium tank Diphasic He pipe Thermal shielding Regulation He valve Intercavities belows Vacuum valve Spaceframe support Heat exchanger Alignement fiducial

9 Volumes of the helium circuits and vessels < 50 l 1,431 bars< Working pressure Ps = 1,04 barg TUV Nord analysis report: The elliptical cryomodules are classified according to PED article 3.3 Compliance with European PED 97/23/EC Cryo pipes designed to reduce the overpressure in case of beam vacuum failure continuous diphasic pipe  =100 with large curvatures 2  =100 bursting disks at each extremity

Integration and Verification Two prototype cryomodules M-ECCTD & H-ECCTD developed, assembled and tested at Saclay (with one 1MW RF source at 704MHz).  Prototype cavities:* 6 Mbeta (≠ final Mbeta cavities from LASA) * Hbeta cavities  power couplers with RF conditioning at Saclay 10 Main objectives: To perform the RF power test the 2 prototype cryomodules in condition that are the closest to the ESS ones before launching the series. Cavities at the nominal performances – at the frequency – without HOM issue Power coupler processed at 1,1MW in the ESS pulsed mode Tests of the Lorentz detuning compensation with the piezo tuners … Main steps: 1.Tests of the M-ECCTD: launch the main procurements with hold point for the Hbeta components 2.RF power test of a single Hbeta cavity with power coupler in horizontal cryostat at Uppsala (HNOSS): launch of the Hbeta cavities of the series 3.Tests of the H-ECCTD: released of the hold point of the procurements of the Hbeta components

Organization at CEA Saclay lab 11 Christine Darve ESS

Budget and cost-book 12 Activity IDActivity name Management & Administration & others Medium Beta Structures M-ECCTD Design, Build and test Medium Beta Cavity Fabrication Medium Beta Cavity follow up Medium Beta Cold Tuning System Medium Beta Power Coupler Medium Beta Cryomodule Equipment (Procurement through production) Medium Beta Cryomodule infrastructure and assembly RF Power Tests of first Medium-Beta Cryomodules Transport of Medium Beta Cryomodule High Beta Structures H-ECCTD Design, Build and test High Beta Cavity Fabrication High Beta Cavity follow up High Beta Cold Tuning System High Beta Power Coupler High Beta Cryomodule Equipment (Procurement through production) High Beta Cryomodule infrastructure and assembly RF Power Tests of first High-Beta Cryomodules Transport of High Beta Cryomodule Total k€ €

Major Procurements M-ECCTD procurements have been launched (FR-SW agreement). Main components already delivered. List major procurement items for the series:  Cavities: see LASA and STFC presentations  Cryomodules components and assembly (CEA Saclay):  Procurement of H-ECCTD and series grouped (H-ECCTD will be a pre series production)  More than 40 large contracts  Priority plan established for the procurements 13

14 Status of the procurement of the main cryostat components: -cavities2 delivered (over 6) -power couplers windows:6 delivered (over 8) -Spaceframe: Delivered -Vacuum chamber: Delivered -MLI of the thermal shield: Delivered -MLI of the cold mass: Delivered -Bellows of the couplers:Delivered - Thermal screen:End of April - Diphasic tube:End of April -Cryo pipes:End of April -Tubes for rupture discs:End of April - Helium heat exchanger:Delivered -Helium valves:Delivered -Intercavity bellowsJuly Instrumentation: part is delivered -Gate valves Delivered -……. Procurement for the M-ECCTD

15 Niobium for 5 cavities [Tokyo Denkai] Coupleur antenna and RF ceramic window [Toshiba] Doorknob transitions [PMB] Magnetic shielding [Meca magnetic] Cold tuning system [Gavard] Motors [Phytron] Piezo actuators [Noliac] Cavity pick-up antennas [Solcera] Coupler pick-up antenna [Solcera] Coupleur vacuum gauges [Pfeiffer] Components already ordered Next procurements New procurement strategy! Five cavities (within a single supplier) Couplers: six external conductors for Qext adjustment Vacuum vessel, spaceframe, thermal shielding Cavity supports, inter-cavity belows and cold-warm transitions Diphasic tubes and cryogenic circuits, MLI Instrumentation New assembly toolings (if needed) Procurement for the H-ECCTD included in the series

16 Procurement strategy About 40 big contracts for the procurement of components of the 30 series cryomodule Contracts must be prepared in 2016 and launched in 2017 in order to meet the ESS time schedule. CEA proposal: include the H-ECCTD cryostat components procurements in the series cryomodule contracts:  Preparation of the CEA teams for the series cryomodule activities  Reduce the number of call for tender  Same manufacturer for the prototype and series components This may induce delays for: procurement of the H-ECCTD components CDR H-ECCTD Launch of the H beta cavities production Possible mitigation = RF power test of a single cavity with power coupler and piezo tuner in HNOOS at Uppsala This may induce delays for: procurement of the H-ECCTD components CDR H-ECCTD Launch of the H beta cavities production Possible mitigation = RF power test of a single cavity with power coupler and piezo tuner in HNOOS at Uppsala

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Top risks 18 Annual Review 23 rd April 2015 The schedule leaves no room for iteration of any of the sub-components or of the cryomodule themselves. The schedule doesn’t let any time for feedback from first cryomodule power testing on the assembly of the following cryomodules. Accelerator design requires very high nominal accelerating gradients (E peak = 45MV/m) and high peak power (P peak =1.1MW). Need of precisely defined interfaces for the cryomodule and its‘ components provided by the different partners, ESS, CEA, LASA and STFC. Launch the mass production before full qualification of the prototype cryomodules to keep the ESS milestones. Escaping the HOMs from the beam line harmonics with a minimum spacing of 5 MHz. (the 2 first Mbeta cavities delivered over 6 being produced have no HOM issue. It seems to be a risk under control if the manufacturing procedures applied to the medium beta prototypes are used for the series production)

Next Six Months M-ECCTD:  Test and qualify Mbeta prototype cavities for the cryomodule assembly  Test and qualify couplers for the cryomodule assembly  Start the CM assembly with the first incoming and qualified components  Complete the RF power test stand at Saclay H-ECCTD:  Launch the 5 prototype cavities production and main cryostat components Production of the cryomodules of the series – Preparation of the major procurements  RF Source 704 MHz for the couplers processing  Vacuum tanks  Industrial studies & CM assembling  Power couplers  Cryogenic pipes  Diphasic titanium pipes – heat exchangers  Spaceframes  Thermal shields – superinsulation layers  Magnetic shields  Tuners  RF conditionning stands for couplers  Assembling tooling Outillages  ….. 19 Collaboration CEA – ESS – LASA – STFC for the production of the cavities of the series Collaboration CEA – ESS – LASA – STFC for the production of the cavities of the series

Summary 20 Prototyping Phases for the M-ECCTD progressing well, with a lot of lessons-learned for the series production (incl. cavities production). The development plan of the H-ECCTD has been modified: the components procurements are included in the procurement of the series and a RF power test of a single cavity equipped with a power coupler will be made in HNOSS at Uppsala The two prototype M-ECCTD and H-ECCTD will permit to qualify components and sub systems and to launch the series production. The main risks are linked to the general ESS tight schedule that let no margin, no room for iteration and for feedback to modify the flow process and to mitigate possible performance degradations. Definition of the main interfaces of the medium-beta (LASA) and of the high-beta (STFC) cavities of the series with the cryomodule are key points and are progressing well. All interfaces to accelerator are being completed.

21 THANK YOU for your attention

22 Extra slides

23 FRAMEWORK OF THE ACTIVITIES ESS – CEA – INFN - STFC 1.Two prototype cryomodules: 2.medium beta:M-ECCTD<= FR-SW agreement 3.High beta:H-ECCTD<= CEA FR In Kind Contribution 2.Production of cavities of the series with RF tests: 3.medium beta cavities<= LASA - IT In Kind Contribution 4.High beta cavities<= STFC - UK In Kind Contribution 3.Production of all other components:<= CEA FR In Kind Contribution (including coupler production with RF power processing) 4.Cryomodule assembling :<= CEA FR In Kind Contribution 5.RF power tests of the cryomodules <= ESS Lund WP5: External WPL: P. Bosland - ESS deputy WPL: C. Darve

24 Test of the HIPPI power coupler on the HIPPI cavity at 1.8 K, full reflection EXPERIENCE OF THE HIPPI POWER COUPLER AT SACLAY HIPPI power coupler (KEK-type window) tested to 1.2 MW, 10% Duty factor at Saclay

25 Doorknob modified to add a bias antenna system Doorknob inner conductor with electrical insulation Antenna water cooling pipes Transition WG / coax at 704MHz (RF adaptation) Bias voltage applied to the antenna: max 10kV Water cooling inside the antenna Bias connector RF trap Antenna water cooling pipes

26 704MHZ RF POWER TEST STANDS 704 MHz RF Plateform Pilot Switch RF Security box water C/C Water vacuum Safety RF Fast acquisition (RF signals, electron pick-up, arc detector by photomultipliers) + slow acquisitions (vacuum…) Signals for fast interlock Coupler Conditioning Security box C/C Water Vacuum Cryo safety RF ESS Cryomodule (ECCTD+ pre-series) Security box C/C Klystron: 704 MHz 1 MW Modulator HT 110 kV Circulator + load waveguides Supratech Cryogenic system Manual switch

27 RF DISTRIBUTION FOR THE TESTS OF THE CRYOMODULES AT SACLAY

28 CRYOMODULE TESTS STAND

29 Proposed Flow chart for the acceptance of the cavities before cryomodule assembly

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