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MQs FiDeL Model

MQs FiDeL Model. Laurent Deniau Magnets, Superconductors and Cryostats Group Technology Department, CERN 28 th April 2009. MQ Cold Measurements. Device: 5m long shaft, 6 sectors, 5 tangential coils Loadline : (STATIC MODEL) Up-down cycle (400A to 11850A) 17 currents with dI / dt =0

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MQs FiDeL Model

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  1. MQs FiDeL Model Laurent Deniau Magnets, Superconductors and Cryostats Group Technology Department, CERN 28th April 2009

  2. MQ Cold Measurements • Device: 5m long shaft, 6 sectors, 5 tangential coils • Loadline: (STATIC MODEL) • Up-down cycle (400A to 11850A) • 17 currents with dI/dt=0 • 2 points per plateau • Geometric @5000A • 25 MQs, 50 apertures (6.4% of 784) • Machine cycle: (DECAY) • Simulate LHC operation (760A to 11850A) • Injection @760A, 1 point every ~30s • Injection 20 minutes (all MQs) • Injection 200 minutes (MQ383) • LHC injection @450GeV, RQD = ~686A, RQF = ~717A • 21 MQs, 41 apertures (5.2% of 784)

  3. TF and Harmonics Geometric

  4. Transfer Function Geometric 1/2 • 1 unit = 10-7 [T.m/A] • Warm stdev = 10.9 units (out layer MQ061) • Warm measurements random error = ~10 units • Geometric stdev = 14.4 units • Cold measurements random error = ~17 units (dominates) • No apparent correlation for Warm-Cold and Aperture 1 & 2 • Cross-correlation W/C = ~1.7 units MQ061

  5. Transfer Function Geometric 2/2 • W/C Offset 28 units, stdev 11.8 units. • Out layer MQ061 removed • 11 apertures removed for the model (22%) • Anormal saturation (MQs 061,120, Ap1 114,173, Ap2 151,268,263,264,384)

  6. Harmonics Geometric • Allowed harmonics • b6: systematic of 3.42 units (stdev 1.2 units) • b10: systematic of -0.19 units (stdev 0.06 units) • Good correlation Warm-Cold and Aperture 1 & 2 • Unallowed harmonics • a4: systematic of 0.41 units • Other systematics are close to zero (<0.1 units) • b3, a3 and a4: random of 1.5 to 1.8 units

  7. TF and Harmonics @Cold

  8. Unallowed Harmonics @Cold • Spread of b3 of 0.5 units for currents <GEO • Contribution from persistent currents

  9. Transfer Function Static Model • The model works well at high current (>GEO) • Strange residual magnetization at low current (1kA to 2.5kA) • Model errors are negligible (<1.3 unit) • Model error at 450GeV (RQD=686A, RQF=717A) is ~1.5 unit

  10. b6 Static Model • The model works very well • Saturation fits well with one component (symmetric curvature) • Model errors are negligible (<0.015 units)

  11. b10 Static Model • The model works well • Up-down asymmetry of persistent currents • Model errors are negligible (<0.035 units)

  12. TF and Harmonics Decay

  13. b6 Decay • The model works well • Time constant of 29 seconds • 90% contrib. comes from the slow component (~270 seconds) • Average decay is 0.56 units after 20 minutes (sigma ~0.45 units)

  14. TF & Other Harmonics Decay • No systematic decay observed • b2 decay is 0.8 units with a spread of 2.8 units • b3, a3 and a4 decay show a spread of 0.3 to 0.4 units

  15. Conclusion • All data are FiDeL 2009 (updated layout) • The geometric is provided for TF and all harmonics • per magnet: 392 magnets, 784 apertures • per circuit: 16 circuits, 32 apertures(stdev) • LHC wide: generic magnet (stdev) • REFPARM: ~17000 records (non-zero ~7000 records) • The static components are provided for (magnet generic) • Model for TF, b6, b10 (model errors are negligible) • Systematic and random for all other harmonics • Random is also given for <GEO and >GEO for MAD • The decay is provided for (magnet generic) • Model for b6 • Systematic and random for TF and all other harmonics

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