8/07/2002 - J.M. Rey 1

J.M. ReyCEA/DSM/DAPNIA/SACM

Saclay

The different (magnetic) ways to run the MICE experiment

8/07/2002 - J.M. Rey 2

Magnetic configurations

3 ways to run the experiement:

• Cold: 1 absorber, 2 detectors.

• Flip: 2 absorbers, 2 flip region, 1coupling, 2 detectors.

• Straight: 2 absorbers, no flip region, 1coupling, 2 detectors

Is that enough!

8/07/2002 - J.M. Rey 3

Cold

-4 ,0

-3 ,0

-2 ,0

-1 ,0

0 ,0

1 ,0

2 ,0

3 ,0

4 ,0

-5 0 4 5 0 9 5 0 1 4 5 0 1 9 5 0 2 4 5 0 2 9 5 0 3 4 5 0 3 9 5 0 4 4 5 0 4 9 5 0 5 4 5 0 5 9 5 0

z position (mm)

Fie

ld (

T)

•Cold: 1 absorber, 2 detectors.

8/07/2002 - J.M. Rey 4

Flip

-4 ,0

-3 ,0

-2 ,0

-1 ,0

0 ,0

1 ,0

2 ,0

3 ,0

4 ,0

0 1 0 0 0 2 0 0 0 3 0 0 0 4 0 0 0 5 0 0 0 6 0 0 0 7 0 0 0 8 0 0 0

z position (mm)

Fie

ld (

T)

•Flip: 2 absorbers, 2 flip region, 1coupling, 2 detectors.

8/07/2002 - J.M. Rey 5

Straight

•Straight: 2 absorbers, no flip region, 1coupling, 2 detectors

-1 ,0

0 ,0

1 ,0

2 ,0

3 ,0

4 ,0

0 1000 2000 3000 4000 5000 6000 7000 8000z position (mm)

Fie

ld (

T)

8/07/2002 - J.M. Rey 6

The detector point of view

-0,15

-0,1

-0,05

0

0,05

0,1

0,15

0,2

0,25

0,3

400 600 800 1000 1200 1400 1600

z position (mm)

Fie

ld (

T)

Flip

Straight

Cold

On axis field contribution of the experiment in the detector:

0.1% for a 5T field

8/07/2002 - J.M. Rey 7

The detector point of view

The adjustement of the field homogeneity in the detectors will require specific compensating coils.

It seems reasonable to consider one set of compensating coils per experiment configuration.

This kind of device may have a significant impact on the costs, especially if they are not mentioned on the specifications!

8/07/2002 - J.M. Rey 8

Some questions?

• What is the lowest magnetic field, or muon momentum, to

be measured in the detector magnets?

• Should the 10-3 field homogeneity be kept even for the

lowest field?

• Are they some more experiment configuration?

• Should we fear the next slide?

8/07/2002 - J.M. Rey 9

Some fear?

-4 ,5

-3 ,5

-2 ,5

-1 ,5

-0 ,5

0 ,5

1 ,5

2 ,5

3 ,5

4 ,5

0 1 0 0 0 2 0 0 0 3 0 0 0 4 0 0 0 5 0 0 0 6 0 0 0 7 0 0 0 8 0 0 0

z position (mm)

Fie

ld (

T)

-10%

+10%

+10%

-10%

8/07/2002 - J.M. Rey 10

Toward magnet specifications!

We have defined:• The inner warm radius: 20 cm.• The good field length and radius: 1.1 m and 15 cm.• The maximum field: 5T.

We need to define:• The minimum field.• All the foreseen experiment configuration.• The range of adjustment for the different coils.