1. HL-LHC WP14 2 nd meeting: Intercepting devices and failure cases to be studied Anton Lechner, Jan Uythoven

2. Intercepting devices and studies Following action of first WP 14 meeting:  Summarise all elements covered by WP14  For each of them define The failure cases and impact scenarios Timeline for studies and production – not now, except TDI  First need to identify if modifications are required Presented here for the protection devices. WP 14 devices not treated here:  Injection kicker magnets MKI  Dump kicker magnets MKD and MKB  Beam dump window and BTVs  Diagnostics in general 2 Intercepting devices and studies HL-LHC WP14, 5/11/2013,

3. Injection protection devices 3 Intercepting devices and studies HL-LHC WP14, 5/11/2013, TDI MKI +90˚ TCDD TCLIB TCLIA Kicker MKI LEFT OF IP2 (H plane) RIGHT OF IP2 (H plane) TCLIM Septum MSI

4. Injection protection devices TDI  Primary injection absorber  Mobile, upgrade needed. Only item for which studies have started TCDD  “Mobile”/fixed, upgrade to be confirmed. Include in TDI study TCLIA  Mobile, upgrade to be confirmed  Maximum opening affects crossing angle, ALICE ZDC for ion operation (see presentation later) TCLIB  Mobile/fixed, upgrade to be confirmed TCLIM  Fixed, upgrade to be confirmed 4 Intercepting devices and studies HL-LHC WP14, 5/11/2013,

5. Failure cases Failure scenarios following injection kicker failure  Injection settings, quench is allowed but not damage Cases  Impact close to jaw edge – possibly limited by tensile stress worries about survival of the jaw Synergy with TCDI studies (Fausto, Alessio) Maximum temperature (step) on surface Also important for coating Sensitivity study to be made by varying position and angle  Full impact – possibly limited by compressive stress Injected beam, no kick Stored beam, full kick  Grazing beam – limited by smaller effective absorber length and resulting reduced protection – study combined protection of TDI and TCDD Injected beam, core of the beam hitting upper edge at entrance of TDI Stored beam, core of the beam hitting lower edge at entrance of TDI 5 Intercepting devices and studies HL-LHC WP14, 5/11/2013, - No sweep to be studied - Reduce number of studies, depending on optics details: -Differences IP2 and IP8: worst case -Symmetry cases for different detector polarities and differences between injected and circulating beam

6. Injection Protection Studies: Normal Operation No quench is allowed, acceptable heating Repeated injection of pilot on the TDI With collimators at injection settings:  Halo scraping not to quench downstream magnets  Beam impedance stored beam at injection Effect of beam on TDI Effect of TDI on the beam With injection collimators open  Beam impedance stored beam, any beam energy Effect of beam on TDI Effect of TDI on the beam 6 Intercepting devices and studies HL-LHC WP14, 5/11/2013,

7. Additional Studies TCLIA / TCLIB / TCLIM (‘other side’ of IP)  Phase coverage of injection protection  In case of change of optics / phase advance relative to Run I studies  For beam impact and new HL-LHC beam parameters No damage to downstream magnets No damage to the absorber  Beam impedance issues? TCDD impedance? 7 Intercepting devices and studies HL-LHC WP14, 5/11/2013,

8. Additional info required LIU parameters to be taken into account: HL-LHC parameters:  We need detailed parameters for impedance calculations  Coherent with LIU parameters given above Optics  Crossing, separation, Twiss Quench and damage levels of D1 and triplet  Iteration -> 8 Intercepting devices and studies HL-LHC WP14, 5/11/2013, OptionSpacingI beam [p+]  x,y [  m] Standard50 ns3.68e112.50 25 ns2.32e112.08 BCMS50 ns2.70e111.95 25 ns2.00e111.37

9. Quench and damage levels D1 and triplet Values used in ‘old’ Functional specification  Damage level: 20 J/g  Fast quenches (injection failure): 5 mJ/g  Quench level ‘slow’ (DC load): 40 mW/g At injection Initial discussion with Arjan roughly confirm the quench levels but the damage level might be significantly lower Re-asses with proper load cases from FLUKA, using latest quench and damage models  Proposal. In the coming weeks For the present TDI and TCDD take existing FLUKA data for grazing incidence Define quench and damage level for the present TDI and TCDD (Bernhard / Arjan): to be written down in a note as reference  Followed by Define new TDI / TCDD configuration - will take several months Repeat FLUKA simulations for new configuration Define quench and damage limit for this configuration: publish this again in a note. 9 Intercepting devices and studies HL-LHC WP14, 5/11/2013,

10. Priorities / timeline Continue with the injection protection studies as this is more urgent than the LBDS studies: needs to be installed in LS2. Injection studies:  Quench and damage limits of D1 and triplet with present TDI and TCDD configuration Grazing incidence case only. FLUKA data available. To be done very soon.  Survival of the TDI using LIU BCMS parameters Limit by tensile stresses Sensitivity analysis on position and angle of the beam Look for new absorber material ! Synergy with TCDI work Will take several months  Protection. Define new TDI and if required new TCDD New materials Most likely multi-module TDI Check of all defined failure cases with FLUKA using SixTrack input Estimate of D1 and triplet quench and damage limits.  TCLI checks in parallel 10 Intercepting devices and studies HL-LHC WP14, 5/11/2013,

11. Dump Protection Devices 11 Intercepting devices and studies HL-LHC WP14, 5/11/2013, TCSG

12. Dump protection devices TCDS  Fixed, upgrade to be confirmed TCDQ  Mobile, upgrade done, installation LS1 ongoing TCSG  Mobile, upgrade most likely not necessary, to be confirmed  Stay compatible with other TCS collimators, buttons TCDQM  Fixed, upgrade most likely not necessary, to be confirmed TDE  Fixed, upgrade most likely not, but study gas handling and dilution. Effect on MKB. 12 Intercepting devices and studies HL-LHC WP14, 5/11/2013,

13. Dump failure scenario’s to be studied Asychronous dump with full HL-LHC beams: quenches allowed but no damage  FLUKA studies for TCDQ done Extend results to TCSG and TCDQM  Will need to be done for TCDS Dump with full HL-LHC beams on TDE: no damage  Estimate allowed repetition rate of dumps – N 2 pressure Experimental and FLUKA data  Do we need to re-assess the number of MKBs which are allowed to simultaneously fail?  Double spiral Do we need it? How much would we gain? 13 Intercepting devices and studies HL-LHC WP14, 5/11/2013,