1 search for worst-case forces mice video conference, september 8, 2004 yury ivanyushenkov applied...

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Search for Worst-Case ForcesSearch for Worst-Case Forces

MICE Video Conference, September 8, 2004

Yury Ivanyushenkov

Applied Science Division,Engineering and Instrumentation Department,

RAL

2

Aims of workGoal: 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?

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STEP I:

STEP II

STEP III

STEP IV

STEP V

STEP VI

By A.Blondel

MICE stages

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Model (without shielding) in OPERA

Model:-18 coils;- no iron shielding

5

255 305

126012060

200

620

263347725

250

841

13751385 12501260

3660

(SFOFO, 200 MeV/c, beta=42 cm, gap =600 mm)

404

Centre coils: J=64.44 A/mm2

Focusing coils: J=113.95 A/mm2

Coupling coils: J=96.21 A/mm2

End #2 coils: J=67.11 A/mm2

255355

202

Matching #2 coils: J=41.46 A/mm2

2440

202

45414721

6041

6161



792

305

Gap=600

MICE magnetic system geometry

Note:Geometry and currents fromUlisse before Osaka meeting

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(SFOFO, p=200 MeV/c, beta=42 cm, gap =450 mm)

4.1 4.1

83.9 13.9

20.8235

228

14236

83.9

13.9

20.8

235

228

14

236

All forces are in tonnes !

147 147








24.3 7

Forces in MICE magnetic system

14

7

2.4 103.5

6.6 22

220225

15.4236 147

12.5 5 15.4

4.1 83.9

13.9 20.8

235228

14236 147

24.3 714



Forces Vs. Gap for p=200 Mev/c

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2.4 2.4

79 9

23.3

336.6

328

21.5340

79

9

23.3

336.6

328

21.5

340


147








147

33.3 8.6


21.5

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Forces Vs. p for gap=450 mm(SFOFO, p=200 MeV/c, beta=42 cm, gap =450 mm)


2.4 79

9 23.3

336.6328

21.5340 147

33.3 8.6 21.5

4.1 83.9

13.9 20.8

235228

14236


147

24.3 714

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(SEMI-FLIP, p=200 MeV/c, beta=42 cm, gap =600 mm)

2.2 2.2

100.8 3.6

14 59.5

46

46.797

100.8

3.6

14

59.5

46

46.7

97


146








146

39.4 13.5


46.7

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(NON-FLIP, p=200 MeV/c, beta=42 cm, gap =600 mm)

1.8 1.8

100.6 3.6

13.7 60.3

45

15.751.5

100.6

3.6

13.7

60.3

45

15.7

51.5


146








146

26.3 15.3


15.7

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Net Force, tonne / Case

SFOFO, p=200 Mev/c, beta=42 cm

SFOFO, p=240 Mev/c, beta=42 cm

SEMI-FLIP, p=200 Mev/c,

beta=42 cm

NON-FLIP, p=200 Mev/c,

beta=42 cm

Gap=450 mm

Gap=600 mm

Gap=450 mm

Gap=600 mm

Gap=600 mm

Gap=600 mm

Central focus pair 0 0 0 0 0 0

Edge focus pair 7from centre

5towards centre

8.6from centre

8towards centre

13.5towards centre

15.3towards centre

Coupling coil 14from centre

15from centre

21.5from centre

23from centre

46.7from centre

15.7towards centre

Tracker solenoid 24.3towards centre

12.5towards centre

33.3towards centre

17.3towards centre

39.4towards centre

26.3towards centre

Summary table for axial magnetic forces

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(SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Focus Coils quenched)

3.4 3.4

80.3 12.1

57.5

0

0

21.1 0

80.3

12.1

57.5

0

0

21.1

0








Focusing coils: J=0 A/mm2

147

6.3 0

Forces in MICE magnetic system: Quenches

21.1

147

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(SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm, Focus Coils quenched)

3.4 80.3

12.1 57.5

0

0

21.1 0


6.3 0

Forces in MICE magnetic system: Quenches (2)

21.1

147


2.4 79

9 23.3

336.6328

21.5340

33.3 8.6 21.5

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(SFOFO, p=240 MeV/c, beta=42 cm, gap =450 mm,

Coupling Coils quenched)

0.8 0.8

77.8 7.8

19

312.7

273

0259.7

77.8

7.8

19

312.7

273

0

259.7


147.3


Coupling coils: J=0 A/mm2






147.3

43.5 39.7


0

16



Coupling Coils quenched)

0.8 77.8

7.8 19

312.7

273

0259.7


43.5 39.7 0

147.3


2.4 79

9 23.3

336.6328

21.5340

33.3 8.6 21.5

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Detector Magnets quenched)

0 0

0 0

0

283.6

314.8

31.3340.7

0

0

0

283.6

314.8

31.3

340.7


0

Centre coils: J=0 A/mm2


End #2 coils: J=0 A/mm2

Matching #2 coils: J=0 A/mm2

Matching #1 coils: J=0 A/mm2

End #1 coils: J=0 A/mm2


0

0 31.2


31.3

18


Detector Magnets quenched)

0 0

0 0

283.6

314.8

31.3340.7


0

0 31.2 31.3



2.4 79

9 23.3

336.6328

21.5340

33.3 8.6 21.5

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Net Force, tonne / Case Normal mode

Coils quenched:

Focus coils Coupling coils

Detector magnets

Central focus pair 0 0 0 0

Edge focus pair 8.6from centre

0 39.7from centre

31.2towards centre

Coupling coil 21.5from centre

21.1from centre

0 31.3from centre

Tracker solenoid 33.3towards centre

6.3from centre

43.5towards centre

0

Summary table for axial magnetic forces: Quench cases SFOFO, p=240 Mev/c, beta=42 cm, gap=450 mm

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Forces in MICE magnetic system: Effect of shielding disks

2.4 103.5

6.6 22

220225

15.4236 147

12.5 5 15.4


5.0 103.6

6.7 22

220225

15.4236 139.9

2.6 515.4

Without shielding disks

With shielding disks

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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

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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 ?

1 search for worst-case forces mice video conference, september 8, 2004 yury ivanyushenkov applied...

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