HL-LHC Annual Meeting, November 2013HQ Planning – G. Sabbi 1 HQ Status and Plans G. Sabbi High Luminosity LHC Annual Meeting Daresbury, UK, November 11-14, 2013

HL-LHC Annual Meeting, November 2013HQ Planning – G. Sabbi 2 HQ Program Status/Plans HQ02: test second-generation HQ coils including  provisions for coil expansion during reaction  provisions for improved electrical integrity  cored cables for suppression of eddy current effects HQ03 model using uniform, final design and process  Realistic field quality & performance reference for HL-LHC Detailed discussion of HQ program status and plans took place in July The resulting summary document is available at: /HQ-plans-2.docx /HQ-plans-2.docx In the next slides, we review and update some of the key points

HL-LHC Annual Meeting, November 2013HQ Planning – G. Sabbi 3 HQ02a-2 Test Summary: results vs. plan Achieve highest possible current at 2.2 K and 4.5K with current configuration First quench above 15kA: no performance loss after thermal cycle Slow training at 2.2K above 15kA, several coils/locations but all in high field (pole) area Clear signs of insufficient pre-load, as expected Fall backs at moderate miits, with slow retraining No performance loss at 4.5K, achieving 98% of SSL at 4.5K and enabling detailed performance studies in many areas: ramp rate, quench velocities, performance degradation limits due to stress, high miits etc. Perform additional magnetic measurements and heater studies Full characterization completed Incorporate acoustic sensor and quench antenna for additional information on quench development -- Completed Resolve inductance questions -- Problem tracked to 15kA header

HL-LHC Annual Meeting, November 2013HQ Planning – G. Sabbi 4 Continue quench protection studies, use temperature that allows highest fraction of SSL – 4.5K Establish miits budget (ok if it detrains but we want to go back within 5% of maximum achieved fraction of SSL) Not possible due to slow training and easy detraining, but 98% SSL allowed to establish no degradation up to 16 miits Complete quench integral study and add small (2.5-5 mOhm) dump resistor Completed no dump and 5 m-Ohm, results are close, 2.5 mOhm must be in between No high miits quenches directly aimed at establishing performance degradation in this test Added: studies in preparation for CLIQ test More details on AC losses, comparison with HQ01e HQ02a2 Test Summary: results vs. plan (2)

HL-LHC Annual Meeting, November 2013HQ Planning – G. Sabbi 5 HQ02b assembly plan Option 1: perform a complete disassembly of HQ02a Attempt to understand and fix faulty strain gauges Reassemble with higher pre-load (level to be discussed) and/or coil configuration changes (update: no coil changes needed) Option 2: Increase the pre-load Currently leaning toward option 2: there is no need to exchange coils, and strain gauge study could be performed separately However, it means no reliable coil stress measurements in HQ02b It would also prevent from removing the warm bore guide blocks  We will have a dedicated meeting in 2-3 weeks to discuss Future HQ02 assembly should include warm magnetic measurements A plan is in place, with FNAL support Include correction of high field errors with magnetic shims Discuss limitations due to presence of guide blocks in option 2

HL-LHC Annual Meeting, November 2013HQ Planning – G. Sabbi 6 Perform 1.9K measurements up to maximum achievable current Establish performance improvements/degradation with higher pre-load Robustness studies: large number of cycles, full accelerator cycle Incorporate/characterize new instrumentation (QA, acoustics etc.) Assess performance of CLIQ system for magnet protection Establish safe miits budget as was planned for HQ02a-2 Extend quench protection studies within safe miits budget Quench integral, heater tests, CLIQ etc. Perform study of degradation vs. MIITS (to be discussed) Perform magnetic measurements (to be discussed) Timeline: with simple pre-load increase, test could start in February; one additional month for full reassembly. Discussion on planning and organization for HQ02b test is starting: test plan/priorities, definition of key roles and responsibilities (LARP/CERN) HQ02b Test at CERN

HL-LHC Annual Meeting, November 2013HQ Planning – G. Sabbi 7 Coil fabrication is progressing well, expect to have coils ready following the test of HQ02b at CERN However, coil strain gauges are an issue: we need to understand and fix reason for failures in HQ02 (and LQS03) This may require dedicated tests/analysis and may cause delays Option 2 assembly for HQ02b means no magnet feedback before HQ03 Also, we want to implement a QXF-style heater design in coil 26 (spare) and possibly in coil 25 (last coil of nominal set) – this is also on the critical path Planning to implement magnetic shims for correction of high current harmonics (based on warm magnetic measurements) and magnetic shims for correction of persistent currents (based on calculations and HQ02 measurements) Need to decide on test location (FNAL or CERN) Discuss status of VMTF upgrade for full current at 1.9K Implement upgrades in the magnetic measurement system (both CERN/ and FNAL) HQ03 Plan