STATUS of INFN contribution to ESS Linac

1. STATUS ofINFN contribution to ESS Linac Santo Gammino Manchester February 1st, 2017

2. Italian committment to ESS Total Planned Commitment (2013 prices): 110,186 M€ ( 6,0% ) CASH: 20,8 M€ (19,0%) IN KIND: 89,39 M€ (81%) Three Institutions involved: CNR-ELETTRA-INFN (INFN acts as representing entity) Total IKC to the accelerator (ELETTRA+INFN): 62.51 M€ Eugenio Nappi Aarhus April 1, 2016

3. ESS Linac & INFN Contribution INFN - LNL INFN - LNS INFN - MI INFN is in charge of: Ion Source & LEBT (LaboratoriNazionali del Sud) Drift Tube Linac(LaboratoriNazionali di Legnaro) Medium Beta Superconducting elliptical cavities (LASA-Milano) The 3 TAshavebeenapproved by INFN Board and signed in 2016 (DTL in April, IonSource&LEBT in June, Medium beta cavities in November)

4. Proton source and LEBT • Done in 2016: • Source and HV platform fully assembled • LEBT and beam instrumentations for phases 1 and 2 fully assembled • All four racks fully assembled • Computers for the source control system fully assembled • Iris fully assembled • Solenoids arrived • Two diagnostic tanks arrived • Chopper ordered • LEBT collimator ordered • Currently under way: • Debugging of beam instruments • Debugging of control system • Characterization of the source • Assembly of the full LEBT 23/01/2016 23/01/2017

5. Status of the installation LEBT is fully assembled and cabled for the beam commissioning phases 1 and 2 Source is fully assembled and cabled

6. Preliminary beam characterization Proton Fraction: 83% (> 75%) Extracted beam: 82 mA (close to goal:90 mA,to be obtained with larger extractor& Alumina wall)Pulse stability: ±1% (better than ±2%)Pulse repeatability: ±1.8% (< ±3.5%) Emittance: 1.06π.mm.mrad(< 1.8)Max divergence: 55mrad(< 80)

7. Ion source & LEBTMajor goals expected for 2017 • Increase the beam current production • Complete characterization of the source in any parameters configuration • Optimization of the beam transport efficiency through the LEBT • Chopper performances (to be completed in Lund) • Space charge compensation optimization • Long duration test (to be completed in Lund) • Packaging and shipping of the full equipment in order to be ready for RFI date (02/11/2017)

8. DTL-Design and Recent achievements • Forged SS tubes, kick off meeting happened, prototype realized, first delivery (tank4, tank3, partial tank1) on 18th week (end April) • Tender for the machining of tanks 3 and 4: Contract with Cinel SRL ready. • Mechanical engineering group in Torino/LNL reinforced, most of the drawings for all tanks and layout ready (tender for machining of tank 1-2-5 submitted to Board of INFN in March?). • PMQ tendering concluded, results transmitted to Board for approval and signature. Rough material for tank 4 mod 3, 304 L forged

9. Recent achievements • Physics design: closed the change for the position of the steerers (regular in betatron phase advance, less redundancy in last tanks) and for the weaker PMQ in tank5 to match the spoke section. • RF Design and stabilizing system verified and bead pulling procedure under preparation (technical meeting with S. Ramberger, preliminary design of a full scale aluminium mock up). • A change request for using the pulsed steerers has been prepared. • Two DT prototypes (PMQ and BPM, same geometry as for steerers) successfully completed (machining and brazing at INFN, e-beam welding in Zanon, magnetic measurements at CERN). • The production of DTs for tanks 4 an 1 will be done internally (same procedure as prototypes)

13. INFN LASA Medium Beta CavityPreliminary Design Report • The PDR was held in Milano on May 19, 2016 to review the INFN cavity design. • The PDR committee reported: • INFN – LASA has completed a very detailed optimization of the medium beta cavity design. The committee was impressed by both the level of detail of the work and the application of LASA’s previous experience in SRF cavity design and production • No technical showstoppers are seen for the medium beta design • Few recommendations were issued mainly on: • Conduct Multipacting Studies • Conduct study of HOMs due to cavity fabrication shape variation This work is nearly completed and reports will be issued soon.

14. INFN LASA MB Cavity Test The INFN LASA cavity was successfully tested @ 2 K, exceeding the ESS specifications. Soft Multipacting barrier Power Rise @ 2 K A soft MP barrier was easily conditioned. This barrier matches with simulations. HOM near 5th machine line 100 W CW cryo power, i.e. 16.7 MV/m @ Q0 5 109 f = 1741.8 MHz (> 19 MHz from machine line) Df < 1 MHz from simulations (f =1742.4 MHz).

15. Cavity Activities • To comply with PDR recommendation: • The committee strongly agrees that the LASA cavity be tested as one of the 4 cavities on the first ECCTD test. We are now integrating the cavity in its He-Tank. The cavity will be vertically tested at LASA after integration prior to send it to CEA for integration in the M-ECCTD module.

16. Series Cavities activities • The Niobium Call-for-Tender will be published in the following days. • The Cavity Call-for-Tender preparation is nearly finished. We expect to send a draft to INFN Legal Office in the next weeks. • We are also working together with DESY to set up the qualification test of the cavities. A meeting is scheduled beginning of February.

17. Summary • A lot of work hasbeendone for ESS in 2016 • Criticality: the large amount of call for tender to be managed on 2017 • 3.3M€ Nb call approved • DTL procurementwell on tracks • DTL : interface meeting wasveryuseful • Ion Source preparation for transfer in fall’17 • Alumina-in-chambertests, LEBT fullyinstalledsoon • Some delaysw.r.t. schedule willnotendanger the RFI for the IS&LEBT (some testspostponedafter RFI); some otherswillbeabsorbed for DTL and for Mb by means of a fasterconstructionphase.