LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 1 Magnet Systems Overview and HQ Program GianLuca Sabbi 2012 DOE Review of LARP SLAC, July 9, 2012 BNL - FNAL - LBNL - SLAC

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 2 LARP Magnet Program Goal: Develop Nb 3 Sn quadrupoles for the LHC luminosity upgrade Potential to operate at higher field and larger temperature margin R&D phases: : technology development using the SQ and TQ models : length scale-up to 4 meters using the LR and LQ models : incorporation of accelerator quality features in HQ/LHQ Program achievements to date: TQ models (90 mm aperture, 1 m length) reached 240 T/m gradient LQ models (90 mm aperture, 4 m length) reached 220 T/m gradient HQ models (120 mm aperture, 1 m length) reached 184 T/m gradient Current activities: Completion of LQ program: test of LQS03 to reproduce TQS03 result Optimization of HQ, fabrication of LHQ (technology demonstration) Design and planning of the MQXF IR Quadrupole development

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 3 Magnet Systems Agenda Morning: 10:45 Overview and HQ programSabbi(45) 11:30LQ program Ambrosio(30) 12:00Discussion (30) Afternoon 13:30Materials programGhosh(30) 14:00LHQ Program and Nb 3 Sn Technology DemonstrationAmbrosio(30) 14:30LHC IR Quadrupole DevelopmentSabbi(30) 15:00Discussion(30)

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 4 R&D Program Components SM TQS HQ  LR LQS LHQ   Racetrack coils, shell based structure Technology R&D in simple geometry Length scale up from 0.3 m to 4 m Cos2  coils with 90 mm aperture Incorporation of more complex layout Length scale up from 1 m to 4 m Cos2  coils with 120 mm aperture Explore force/stress/energy limits Address accelerator quality requirements

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 5 Technology Demonstration Chart

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 6 Overview of LARP Magnets SQ SM TQS LR LQS HQ TQC

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 7 Program Achievements - Timeline (1/3) Mar SQ02 reaches 97% of SSL at both 4.5K and 1.9K Demonstrates MJR 54/61conductor performance for TQ Jun. 2007TQS02a surpasses 220 T/m at both 4.5K and 1.9K(*) Achieved 200 T/m goal with RRP 54/61 conductor Jan LRS02 reaches 96% of SSL at 4.5K with RRP 54/61 Coil & shell structure scale-up from 0.3 m to 4 m July 2009TQS03a achieves 240 T/m (1.9K) with RRP 108/127(*) Increased stability with smaller filament size Dec TQS03b operates at 200 MPa (average) coil stress(*) Widens Nb 3 Sn design space (as required…) (*) Tests performed at CERN

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 8 Program Achievements - Timeline (2/3) Dec LQS01a reaches 200 T/m at both 4.5K and 1.9K LARP meets its “defining” milestone Feb. 2010TQS03d shows no degradation after 1000 cycles(*) Comparable to operational lifetime in HL-LHC July 2010 LQS01b achieves 220 T/m with RRP 54/61 Same TQS02 level at 4.5K, but no degradation at 1.9K Apr. 2011HQ01d achieves 170 T/m in 120 mm aperture at 4.5 K At HL-LHC operational level with good field quality Oct HQM02 achieves ~90% of SSL at both 4.6 K and 2.2 K First demonstration coil with reduced compaction (*) Test performed at CERN

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 9 Program Achievements - Timeline (3/3) Apr HQ01e reaches 184 T/m at 1.9K (*) Still using first generation coils, several known issues Above linear scaling from TQ (240/120*90=180 T/m) Jun. 2012HQM04 reaches 97% SSL at 4.6K and 94% at 2.2K Successful demonstration of revised coil design Single-pass cored cable, lower compaction Next Steps: Aug. 2012LQS03 test: reproduce TQS03 using 108/127 conductor Dec HQ02a test: improve performance with 2 nd generation coils (*) Test performed at CERN

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 10 Recommendations of 2011 DOE Review 1.Undertake a substantial effort for modeling energy deposition and radiation damage from beam losses and other collider issues related to the IR quad aperture decision  This is the task of Design Study WP 10 (Energy Deposition)  Led by CERN but Work Package co-leader is Nikolai Mokhov  On magnet side prepare for use of rad-hard epoxies, if required Status/plans will be discussed in following presentations 2.Establish a formalism for the dialog and protocol which will provide the needed specifications in time to meet agreed upon milestones  Design study WP1 (management) includes parameter control  Various channels to discuss magnet development plans  However, formal protocol still needs to be established

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 11 Program Organization

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 12 FY12 Initial Budget

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 13 FY12 Mid-Year Contingency Allocation

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 14 R&D and Prototype Funding Profiles

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 15 Summary Steady progress in addressing technology issues that were initially perceoved as potential show stoppers Examples: conductor performance, cabling, degradation due to stress/cycling, length scale up, structure and coil alignment, field quality, training, quench protection, cooling, radiation lifetime However, need to catch up in addressing accelerator quality and production relevant features, after a long period spent on more basic issues control of eddy currents, rad-hard components, insulation systems compatible with long magnets, more robust insulation in general, process documentation and QA, evaluation of latest generation of conductors Stepped up the pace in introducing these features, generally good results but some risk Present overall strategy for evaluation/introduction of rad-hard materials Stepping up the pace, ok for now, but some risk Funding details to be discussed in following talks

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 16 High-Field Quadrupole (HQ) Design 120 mm aperture, coil peak field of 15.1 T at 219 T/m (1.9K SSL) 190 MPa coil stress at SSL (150 MPa if preloaded for 180 T/m) Stress minimization is primary goal at all design steps (from x-section) Coil and yoke designed for small geometric and saturation harmonics Full alignment during coil fabrication, magnet assembly and powering

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 17 Contributions to the HQ Development Cable design and fabricationLBNL Magnetic design & analysisFNAL, LBNL Mechanical design & analysis LBNL Coil parts design and procurementFNAL Instrumentation & quench protectionLBNL Winding and curing tooling designLBNL, FNAL Reaction and potting tooling designBNL Coil winding and curingLBNL, (CERN) Coil reaction and pottingBNL, LBNL, (CERN) Coil handling and shipping toolingBNL Structures (quadrupole & mirror) LBNL, FNAL, BNL Assembly (quadrupole & mirror)LBNL, FNAL, (BNL, CERN) Magnet testLBNL, FNAL, (CERN) Accelerator IntegrationBNL, LBNL, FNAL, (CERN)

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 18 HQ Performance Issues Time (s) Extraction Voltage (V) Mechanical issues: Ramp rate dependence of first three models is indicative of conductor damage Electrical issues: Large number of insulation failures in coils, in particular inter-layer and coil to parts HQ01b extraction voltage HQ01a-d Ramp Rate dependence

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 19 Coil Analysis Findings Both mechanical and electrical issues were traced to excessive compaction during the coil reaction phase: HQ design assumed less space for inter-turn insulation than TQ/LQ  Reaction cavity limits radial & azimuthal expansion No/insufficient gaps were included between pole parts to limit longitudinal strain Coil spring back in tooling (Over) size measurements of completed coil

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 20 Initial confirmation by Coil Test in Mirror Mirror structure allows to test single coils: Efficient way to study design variations Two special coil were fabricated and tested: #12-HQM01: larger cavity (& cored cable) #13-HQM02: standard cavity, one less turn Results: Coil 12 showed some performance limitations, probably related to splice fabrication oversight Coil 13: significant improvements over previous coils, both at 4.5K and 1.9K, using RRP54/61 Ramp rate dependence

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 21 Coil Design Revisions and Verification Based on the analysis and tests results, the following changes were applied: A new cable design was developed using smaller strand diameter (from mm to mm, to decrease compaction without changes in parts and tooling Longitudinal gaps were progressively increased and 4mm/m was selected Some end part modifications to increase insulation layers, avoid sharp points Increased inter-layer insulation layer thickness to 0.5 mm Verification of new design: Test of coil 14 (first coil of the new design) in the mirror structure (Dec-Jan) HQ01e test at CERN: evaluate 1.9K performance and perform independent magnetic measurements (Jan-Feb) Test of coil 15 (new design and cored cable) in HQ or HQM (Mar-Apr) A new effort is being organized to understand persisting electrical weaknesses (shorts in coil 14) and apply findings/corrections to both HQ and LHQ

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 22 Accelerator Quality Requirements Detailed specifications will be developed by the HL-LHC design study Preliminary guidance was formulated by CERN in four areas: Ramp rate: no quench at -150 A/s, starting from 80% of SSL Requires control of eddy current losses, particularly in cables Transfer function: < 1 unit reproducibility in the operating range I max /2 Requires control of magnetization and eddy current effects Persistent currents: injection |b 6 |<10 units, spread < 10 units Requires control of conductor magnetization Magnetic center: stable during ramp-up within ± 0.04 mm Requires control of magnetization and eddy current effects

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 23 Current Accelerator Quality Developments Structure optimization for alignment, uniform pre-load, minimal training Field quality measurements and new design features to meet requirements Structure development oriented toward magnet production and installation Quench protection, rad-hard epoxy and cooling system studies

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 24 HQ01d-e Magnetic Measurements Geometric harmonics are small, indicating good uniformity and alignment Large persistent current effects indicate need for smaller filament conductors Large dynamic effects indicate need to better control inter-strand resistance Geometric and persistent current harmonics Eddy current harmonics for different ramp rates

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 25 HQ Funding History and Projection

LARP DOE Review, 7/9/2012Magnet Systems Introduction – G. Sabbi 26 Summary