1. Status of the LSS5 beam dump and proposed relocation of LSS5 systems Etienne Carlier on behalf of LIU-SPS LSS5 Dump Working Group LIU-SPS Coordination Meeting 28-10-2015

2. Outline Ongoing activities Kickers Dump Radio Protection LSS5 relocation UA9 Instrumentation Others LSS1 reconfiguration Civil Engineering Summary

3. LSS5 Internal Beam Dump – Optics 3 MKDVs One upstream the QD.517 and two after (better use of kicker strength) Better dynamic range 3 MKDHs As today New MKDH & MKDV tracking functions Better use SPS apertures Single dump for all energies and beam types No low energy TIDH dump Francesco Velotti (TE-ABT) (3oo3)(2oo3)

4. Vertical Kicker – LSS5 Layout One additional MKDV magnet (Type 2 with large aperture) Upgrade MKDV “thyragnitron” switches to semi-conductor switches No common mode point of failure anymore Additional redundancy in case of failure (2oo3 still on the dump) Reduced operational voltage (reduced probability of magnet breakdown)

5. Vertical Kicker – Pulse generator Prototype 2 Ohm PFN Tested in 867 Semiconductor switch and trigger transformer development (10 GTO stack) Mechanical parts partially produced Ring gate GTO test (2 Ohm PFN & MKDV1 magnet) Promising results down to 50 V/GTO; Turn On delay reasonably constant; To be confirmed on full scale (single GTO measurement - not full current) With recent architecture modifications (3 MKDV magnets - 34 kV range) Final design will be 1 x 12 GTO stack (instead of 2 stacks of 10 GTOs) Offer several advantages for PTM design for and total switch inductance Vertical tracking function to be frozen (dump optic) Switch design Power trigger design Viliam Senaj (TE-ABT)

6. Vertical Kicker - Triggering Circuit C0 – storage capacitor Q – IGBT switch D – freewheel diode L0 – transmission line inductance Cp – peaking capacitor MS – magnetic switch R - load Figure 2 Sample waveforms from the circuit shown on Figure 1 Figure 1 Example of a pulse compression circuit Trigger Module basic specification reminder Current rise rate (min value)1 kA/us  Current rise rate (nominal value)2 kA/us  Peak current at the end of rise time (min value)1kA  *Holding current @22μs (min value)250A NA Turn-on delay time (max value)500ns  PTM Redundancy (2 per swicth)Yes  * The specified holding current @22 μs of the pulse was not studied so far, the related dimensioning steps were omitted at this study stage. Next Power switch selection (IXYS HV IGBT or APP Fast Thyristor) Serial diode selection for redundancy implementation Test on under real condition (Trigger Transformer and GTO switch) for performance and stress validation Maximum turn-on delay for re-triggering to be defined High precision measurement of pulsed output current Janusz Rodziewicz (TE-ABT)

7. FMECA and Fault Tree Analysis of the current and the future system Identification of the best layout in terms of reliability Beam Beam Dump PFN DCPS TL Magnet Resistor Switch Triggering/ Retriggering System boundary Beam Beam Dump PFN DCPS Switch Triggering/ Retriggering System boundary TL Magnet Resistor TL Magnet Resistor Reliability Analysis (Vertical Kicker)Reliability Analysis – Vertical Kicker Miriam Blumenschein (TE-ABT)

8. Kicker Platform Location In ECA5 110 m2 needed for kicker HV generators, electronics and controls Access to kicker platform “not” required during beam operation New ECA5/ECX5 access system sectorization required for “easy” access to ECA5 in case of intervention Infrastructure not available (false floor, 1t crane…) Integration still to be done. Required modifications of SPS access system taken into account in the frame of the “SPS Access System Renovation Project”.

9. R2E in ECA5 450 GeV Maximum MKDV PFN voltage34.8 kV (/12 = 2.9 kV/GTO) GTO (5STH20H4502) SEBc-s @ 2.9 kV/GTO [cm 2 ]8e-9 Number of GTO72 IGBT (IXGN100N170) SEBc-s @1.175kV/IGBT [cm2]8e-9 No of IGBTs72 HEH fluence estimation [HEH.cm- 2.y- 1 ]2e5 Estimated SEB failure rate [y- 1 ]0.3 (0.15 GTO + 0.15 IGBT) HEH limit for 1 SEB/Y [HEH.cm- 2.y- 1 ] 6e5 Low radiation levels to be expected in ECA5 based on RP radiation calculations Cross-check ongoing by RP prior releasing the final calculation report Standalone RadMons (BatMons) installed on both side of the shielding. If radiation levels are confirmed, ECA5 location will be clearly suitable for the kicker system Radiation tests at CHARM scheduled for next year of some power components (GTO & IGBT) Screen for high reliable parts (not prone to destructive failures at low fluence) Exclude a very low failure probability

10. Dump Block - Design Florian Pasdeloup & Antonio Perillo Marcone (EN-STI) The design considered for the first simulations is more or less the one of the current TIDVG : Blocks hit by the beam Cooling circuit in the copper jacket Block pressed mechanically on the copper Graphite blocks Tungsten block Copper block Copper jacket (Ø500mm) First steel shielding (Ø850mm)

11. Dump Block - Design Activities started and still on going First thermo-mechanical simulations (EDMS 1529382): First results validate the choice of materials for the absorbing blocks and the copper core. A concept for the copper core of the system is under study. Design done by EN/STI/TCD (F. Pasdeloup). Concept (EDMS 1547965) has been presented to : Manufacturing experts (A. Dallochio, G. Favre, JM. Geisser, P. Naisson, D. Grenier) Vacuum experts (C. Garion, C. Pasquino, A. Harisson) Welding control expert (JM. Dalin) Electron beam welding expert (T. Tardy) The conclusion of these meetings is that the concept seems realistic and feasible. Some points need to be validated but nothing appears to be a show- stopper for this design. A prototype seems to be necessary to validate the concept. The prototype would be a short sector of 500mm of the coper core with a cooling plate. Florian Pasdeloup & Antonio Perillo Marcone (EN-STI)

12. Dump Block – Copper Core Concept Florian Pasdeloup & Antonio Perillo Marcone (EN-STI) The design of a test bench to characterise the Thermal Contact Conductance is on going. Design done by EN/STI/TCD (F. Pasdeloup and O. Yang Fu Teng) In order to improve the thermal heat exchange between the absorbing blocks and the cooling circuits, a principle of “flexible” cooling plates has been designed

13. Dump Block - Alignement The design of the actuator (dump core support) is on going by EN/MME (J. Humbert). The principle used is the one of the actuator of the LINAC4. Idea suggested by F. Pasdeloup and validated by alignment expert (P. Bestman) The design of the system to take reference on the core through the external shielding is on going. Design by EN/MME (J. Humbert). Concept proposed by alignment expert (P. Bestman). Florian Pasdeloup & Antonio Perillo Marcone (EN-STI)

14. Dump and Shielding Design Next First shielding No special difficulties expected External shielding Complex (inter-connection, ventilation, dump exchange…) Coil masks No special difficulties expected Extremities connections The principle of the semi-automatic connection MKT used on collimators should be a good solution Florian Pasdeloup & Antonio Perillo Marcone (EN-STI)

15. Radio Protection Feasibility studies for the future SPS beam dump focused on three main RP aspects: Residual dose rates to be expected after beam operation around dump, dump shielding and QD519; Prompt dose studies to assess personnel access in ECA5; Radiation to electronics studies in ECA5; Air activation studies. The proposed shielding will allow to work without restrictions after beam operation outside the dump area (acceptable radiation levels). Further cost optimization remains. Prompt dose rates in junction area and ECA5 and personnel access in ECA5 should be feasible. Elevator shaft and staircases in junction area may be problematic. (this was confirmed after simulation of beam losses in ECX5) R2E studies in ECA5 show that installation of electronics in that area should be feasible. A preliminary design proposal for a vented dump has been made. Mathieu Baudin & Helmut Vincke (DGS-RP)

16. Crystals Scraper Collimator Detector Absorber Roman Pot Scraper S. Montesano LSS5 - UA9 Relocation Simone Montesano (EN-STI)

17. Crystals Scraper Collimator Detector Absorber Roman Pot Scraper MKDV1 MKDV2+3MKDH 1+2+3 QFA518 BSGBlockMasks LSS5 - UA9 Relocation Simone Montesano (EN-STI)

18. LSS5 - UA9 Relocation Leave the UA9 devices in place: New goniometers with increased aperture Crystals on the dogleg Dumped beam during UA9 data taking will potentially hit the crystal Invert crystals extraction or Invert kicker horizontal deflection under investigation Radiation dose downstream the new dump should not be an issue Move UA9 devices: Remove TCXHW.51651 Move crystals (TCPC.51795, TECS.51797, TECS.51799) 60m upstream (at QF.51610) Move absorber (TACW.51998) 60m upstream (at QF.51810) Move detectors and collimator (TCSM.51934, XRPH.51937, BSHV.51991) in between crystals and absorber Leave the devices in the dispersive area in place After each object there is a pair of scintillators and an LHC-type BLM that should be moved with the object Baseline Simone Montesano (EN-STI)

19. Beam Current Transformers Scraper Ionisation Profile Monitor (H) Beam-beam wire Wire Scanner LSS5 – Instrumentation Relocation Ionisation Profile Monitor (V) Wire Scanner

20. LSS5 – Instrumentation Relocation Ionisaton profile monitor (H)Leave in PlaceOne MDHW less MDHW+BIPM.51634 MDHW.51637 ScraperRemoveIncluding Shieldings in 51661 & 51698 BSHV.51639 Linear Wire ScannerMove after QD.519 BWSD.51731 Ionisation profile monitor (V)Move after QD.519*One MDVW less MDVW + BIPMV.51734 MDVW.51736 Rotational Wire ScannerMove after QD.519 BWSRE.51740 Beam-beam wire BBLR.51760Remove BBLR.51771Remove BBLRM.51772Move after QD.519 BBLRM.51774Move after QD.519 MDVB.51777Move after QD.519BBLRM compensation Beam Current TransformerMove after QD.519*Separate BCTDC? Aperture to be checked. BCTDC.51895 BCTDC.51897 BCTFS.51894 * UA9 collimator and roman pots will have to be shifted by ~2m downstream (t.b.c.)

21. Collimators Collimator Test Bench eCloud test bench eCloud LSS5 – Relocation (Others)

22. CollimatorMove after QF.516Collimator test stand TCRMP.51737 eCloud test benchMove afer QD.117Move to LSS1 MDPH.51753 MPDH.51754 MDHW.51832 MDHW.51836 MDHW.51838 MDHW.51853 CollimatorRemoveUsers not identified BRCV.51899 BRCH.51902 Move eCloud test bench to LSS1 Reserve space for collimator test stand after QF.516

23. LSS1 - Reconfiguration Kickers DumpSEM DumpSEM

24. LSS1 - Reconfiguration Quad QDA.117Replace by QD QFA.118Replace by QFQFA will be used in LSS5 QDA.119Keep KickersRemove MKDVA.11731 Will be used for eCloud test bench. Aperture to be checked> MKDVB.11736 MKDHA.11751 MKDHA.11754 MKDHA.11757 InstrumentationRemove TFDH.11792 TFDV.11879 DumpRemove TIDH.11795 Replace by passive mask for scraper? TIDV.11892 Replace by passive mask for scraper? Vacuum chamber size to be adjusted Actual vacuum sectorisation to be checked Reason of QFA.116 (large aperture Quad) to be checked Dogleg will be removed Aperture for proton and ion injection checked

25. Civil Engineering - Planning ActivityWhenComment Re-concrete ECA5 floorYETS15-16Including part behind shielding wall ECX5 platform enhancement (Phase 1) EYEST16-17Concrete formwork behind the shielding location ECX5 platform enhancement (Phase 2) YETS17-18Compensation loss of volume after concrete drying Tunnel enlargementLS2Expected duration: 9 months Purchase process for platform enhancement and tunnel enlargement started Removable concrete layer behind shielding to confirmed Cohabitation civil engineering and LSS5 re-cabling campaign during LS2 to be analysed

26. Civil Engineering – Dump Storage Solution for “hot” dump storage to be found (storage pit in ECX5 option to complicated taking into account the risk of flooding) -Behind the dump -In the dump enhancement -On ECX5 gound level -….

27. Activity during YETS15-16 Cleaning ECA5 Removal of remaining ATLAS components ECX5/ECA5 Shielding opening Removal of the first layer of the shielding Overall shielding will be lovered about 800mm Improvment of the shielding efficiency at the bottom of the wall Green light from RP for this change Re-concrete of floor in ECA5 and behind the shielding wall Removal of water cooled cables in LSS5 (TS5-/TS5+)

28. Summary Design activities on going for critical hardware components Kickers Dump optic to be frozen for tracking function definition Re-triggering delay to be analysed Dump Complex external dump shielding Relocation in LSS5 feasible eCloud test bench to be relocated in LSS1 Some aperture issues still to be checked Space Reservation Document in preparation Reconfiguration of LSS1 studied Impact of others projects still to be analysed Space Reservation Document in preparation Civil Engineering in preparation phase for tendering Activities duration during LS2 may become an issue (cohabitation with re- cabling campaign) Solution for storage of “hot” dump in ECX5 to be found