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Search for Worst-Case Forces. Yury Ivanyushenkov Applied Science Division, Engineering and Instrumentation Department, RAL. MICE Video Conference, September 8, 2004. Aims of work. Goal: find maximal (static and dynamical) possible forces in MICE magnetic system.
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Search for Worst-Case Forces Yury Ivanyushenkov Applied Science Division, Engineering and Instrumentation Department, RAL MICE Video Conference, September 8, 2004
Aims of work Goal: find maximal (static and dynamical) possible forces in MICE magnetic system. Method: calculation of axial magnetic forces in MICE by using OPERA package (and other codes). Cases to be analyzed: - MICE stages III, IV, V and VI (see next slide): Parameters (proposal): magnetic modes - flip, semi-flip and non-flip; momentum (MeV/c) – 140, 170, 200, 240; beta (cm) – 7, 15, 25, 42; gap focus coil – match coil (mm) - 450 (was 600); coil currents - 0 (coil is off or quenched), nominal, max (critical current ?); magnetic shielding – with and without. - Abnormal cases: - dynamical forces during quenches; - anything else?
By A.Blondel STEP I: STEP II STEP III STEP IV STEP V STEP VI MICE stages
Model (without shielding) in OPERA • Model: • 18 coils; • no iron shielding
MICE magnetic system geometry (SFOFO, 200 MeV/c, beta=42 cm, gap =600 mm) 250 620 Gap=600 120 1260 200 60 202 202 841 725 404 255 305 305 355 347 263 255 1260 792 1385 1375 1250 2440 3660 4541 4721 End #1 coils: J=65.22 A/mm2 6041 End #2 coils: J=67.11 A/mm2 6161 Centre coils: J=64.44 A/mm2 Matching #1 coils: J=65.06 A/mm2 Note: Geometry and currents from Ulisse before Osaka meeting Matching #2 coils: J=41.46 A/mm2 Focusing coils: J=113.95 A/mm2 Coupling coils: J=96.21 A/mm2
Forces in MICE magnetic system (SFOFO, p=200 MeV/c, beta=42 cm, gap =450 mm) All forces are in tonnes ! 4.1 13.9 235 14 236 14 147 235 13.9 4.1 147 83.9 20.8 228 236 228 20.8 83.9 7 24.3 14 End #1 coils: J=61.59 A/mm2 End #2 coils: J=67.11 A/mm2 Centre coils: J=64.44 A/mm2 Matching #1 coils: J=56.30 A/mm2 Matching #2 coils: J=75.17 A/mm2 Focusing coils: J=113.95 A/mm2 Coupling coils: J=96.21 A/mm2
Forces Vs. Gap for p=200 Mev/c (SFOFO, p=200 MeV/c, beta=42 cm, gap =600 mm) 236 15.4 220 6.6 2.4 147 225 22 103.5 5 12.5 15.4 (SFOFO, p=200 MeV/c, beta=42 cm, gap =450 mm) 236 14 235 13.9 4.1 147 228 20.8 83.9 7 24.3 14
Forces in MICE magnetic system (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm) All forces are in tonnes ! 147 2.4 9 336.6 21.5 340 21.5 336.6 9 2.4 147 79 23.3 328 340 328 23.3 79 8.6 33.3 21.5 End #1 coils: J=61.59 A/mm2 End #2 coils: J=67.11 A/mm2 Centre coils: J=64.44 A/mm2 Matching #1 coils: J=66.82 A/mm2 Matching #2 coils: J=83.07 A/mm2 Focusing coils: J=136.74 A/mm2 Coupling coils: J=115.45 A/mm2
Forces Vs. p for gap=450 mm (SFOFO, p=200 MeV/c, beta=42 cm, gap =450 mm) 236 14 235 13.9 4.1 147 228 20.8 83.9 7 24.3 14 (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm) 340 21.5 336.6 9 2.4 147 328 23.3 79 8.6 33.3 21.5 All forces are in tonnes !
Forces in MICE magnetic system (SEMI-FLIP, p=200 MeV/c, beta=42 cm, gap =600 mm) All forces are in tonnes ! 146 2.2 3.6 59.5 46.7 97 46.7 59.5 3.6 2.2 146 100.8 14 46 97 46 14 100.8 13.5 39.4 46.7 End #1 coils: J=64.01 A/mm2 End #2 coils: J=67.11 A/mm2 Centre coils: J=63.81 A/mm2 Matching #1 coils: J=68.33 A/mm2 Matching #2 coils: J=34.99 A/mm2 Focusing coils: J=68.03 A/mm2 Coupling coils: J=93.10 A/mm2
Forces in MICE magnetic system (NON-FLIP, p=200 MeV/c, beta=42 cm, gap =600 mm) All forces are in tonnes ! 146 1.8 3.6 60.3 15.7 51.5 15.7 60.3 3.6 1.8 146 100.6 13.7 45 51.5 45 13.7 100.6 15.3 26.3 15.7 End #1 coils: J=64.01 A/mm2 End #2 coils: J=67.11 A/mm2 Centre coils: J=63.81 A/mm2 Matching #1 coils: J=68.33 A/mm2 Matching #2 coils: J=34.99 A/mm2 Focusing coils: J=68.03 A/mm2 Coupling coils: J=93.10 A/mm2
Forces in MICE magnetic system: Quenches (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Focus Coils quenched) All forces are in tonnes ! 147 3.4 12.1 0 21.1 0 21.1 0 147 12.1 3.4 80.3 57.5 0 0 0 57.5 80.3 0 6.3 21.1 End #1 coils: J=61.59 A/mm2 End #2 coils: J=67.11 A/mm2 Centre coils: J=64.44 A/mm2 Matching #1 coils: J=66.82 A/mm2 Matching #2 coils: J=83.07 A/mm2 Focusing coils: J=0 A/mm2 Coupling coils: J=115.45 A/mm2
Forces in MICE magnetic system: Quenches (2) (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm) 340 21.5 336.6 9 2.4 328 23.3 79 8.6 33.3 21.5 (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Focus Coils quenched) 0 21.1 0 147 12.1 3.4 0 57.5 80.3 0 6.3 21.1 All forces are in tonnes !
Forces in MICE magnetic system: Quenches (3) (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Coupling Coils quenched) All forces are in tonnes ! 147.3 0.8 7.8 312.7 0 259.7 0 312.7 7.8 0.8 147.3 77.8 19 273 259.7 273 19 77.8 39.7 43.5 0 End #1 coils: J=61.59 A/mm2 End #2 coils: J=67.11 A/mm2 Centre coils: J=64.44 A/mm2 Matching #1 coils: J=66.82 A/mm2 Matching #2 coils: J=83.07 A/mm2 Focusing coils: J=136.74 A/mm2 Coupling coils: J=0 A/mm2
Forces in MICE magnetic system: Quenches (4) (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm) 340 21.5 336.6 9 2.4 328 23.3 79 8.6 33.3 21.5 (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Coupling Coils quenched) 259.7 0 312.7 7.8 0.8 147.3 273 19 77.8 39.7 43.5 0 All forces are in tonnes !
Forces in MICE magnetic system: Quenches (5) (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Detector Magnets quenched) All forces are in tonnes ! 0 0 0 283.6 31.3 340.7 31.3 283.6 0 0 0 0 0 314.8 340.7 314.8 0 0 31.2 0 31.3 End #1 coils: J=0 A/mm2 End #2 coils: J=0 A/mm2 Centre coils: J=0 A/mm2 Matching #1 coils: J=0 A/mm2 Matching #2 coils: J=0 A/mm2 Focusing coils: J=136.74 A/mm2 Coupling coils: J=115.45 A/mm2
Forces in MICE magnetic system: Quenches (6) (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm) 340 21.5 336.6 9 2.4 328 23.3 79 8.6 33.3 21.5 (SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Detector Magnets quenched) 340.7 31.3 283.6 0 0 0 314.8 0 0 31.2 0 31.3 All forces are in tonnes !
Summary table for axial magnetic forces: Quench cases SFOFO, p=240 Mev/c, beta=42 cm, gap=450 mm
Forces in MICE magnetic system: Effect of shielding disks (SFOFO, p=200 MeV/c, beta=42 cm, gap =600 mm) Without shielding disks 236 15.4 220 6.6 2.4 147 225 22 103.5 5 12.5 15.4 With shielding disks 236 15.4 220 6.7 5.0 139.9 225 22 103.6 2.6 15.4 5
Conclusions • Conclusions (preliminary): • so far, the highest net forces on modules are created in SEMI-FLIP mode (but the highest net force on the edge focus pair is in case of NON-FLIP mode) • -> it seems there is no a single worst case for all the modules; • for FLIP mode forces are the highest for 240 MeV/c; • both the edge focus pair and the tracker solenoid (but not the coupling coil) are sensitive to the value of the gap; • forces change when some of coils are quenched; • shielding disks change forces on the detector module
Next steps • New set of currents for various MICE stages and magnetic modes • has been recently released by Ulisse Bravar. • Proposal for the next steps: • agree on parameter space for force cases; • get from Ulisse a complete set of currents (and geometries) • for all stages and magnetic modes; • ask John Cobb to make a quick scan of parameter space by using his code • to indicate the worst cases; • check worst cases with OPERA including shielding in the model; • collect recommendations from the Collaboration on abnormal cases and include • these cases into the analysis; • dynamical cases – ask for help from magnet experts; • anything else ?