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Field induced by the line sources

The normal component of

 

 

 

 

 

the field intensity induced

 

 

P

 

 

by the charged line in the

 

 

 

cylinder center

 

b

 

 

 

 

 

 

 

 

C

1

 

 

a

C

EnC

 

 

 

 

 

 

 

B

 

2 0

r

A

 

 

 

 

 

 

 

The normal component of the field intensity induced by the charged line in the inverse point:

EnB

B

1

cos

2 0

a

21

Geometrical relations

The normal component of

 

 

 

 

 

 

 

P

 

 

 

 

 

 

 

b

 

 

 

the field intensity induced

 

 

 

 

 

 

a

 

by the surface charges

 

 

 

 

 

 

C

 

 

 

 

 

 

may be expressed as

 

 

A

 

 

 

 

 

B

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

1

 

 

 

 

 

2

1

 

1

 

 

E

 

cos( )

 

 

 

 

 

 

 

 

 

 

 

 

 

 

n

2 0

 

2

 

 

a

 

2 0

 

2

 

 

 

 

 

 

 

1

 

 

1 r

 

 

The first term corresponds to field induced by the charged line in the inverse point. The second term corresponds to field induced by the charged line in the central point.

 

 

 

 

 

2

1

 

 

 

 

 

 

2

1

 

 

B

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

 

2 0

 

2

 

 

 

 

2 0

 

2

 

 

 

 

 

 

1

 

 

 

 

1

22

The field sources for the external domain

0

r

0

 

 

A B C

00

 

0

0

 

23

The field sources for the internal domain

0

r

0

 

 

A C

2 0 0

24

Application of the Images Method for calculating magnetic fields in the presence of cylindrical objects

25

Image method for the flat boundary between magnetic media.

 

 

 

 

 

H (1)

 

H

(2)

 

 

 

Boundary conditions:

1

n

 

2

 

n

 

 

 

 

 

 

 

 

 

 

 

i

y

 

 

 

H (1)

H (2)

 

 

 

 

 

 

 

 

 

 

 

 

1

h

r

x

For the chosen coordinate system:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H

(1)

 

H

(2)

 

 

 

2

 

1

y

 

2

 

y

 

 

 

 

 

H x(1)

H x(2)

 

 

 

 

 

 

 

26

Equivalent magnetic charge density.

Assuming the same magnetic permeability in the whole space:

1

i y

1

h

r

x

 

 

 

 

 

 

 

 

 

1

 

 

 

Charge density H y(1)

 

m

H y2

 

 

 

 

 

1

 

 

(x) 2

1 2B(ext)

 

m

 

1

 

n

 

 

 

2

(1)

(ext)

 

 

m

Hn

Hn

 

 

 

 

2 1

 

 

 

 

(2)

(ext)

 

 

m

Hn

Hn

 

 

 

 

 

 

 

2 1

 

 

 

 

 

27

The field in the presence of a cylindrical magnetic object

0

r

 

i

 

A C

28

The field sources for the magnetic field intensity in the external domain

0 r 0

A B C i

i 0

0

i 00

29

The field sources for the magnetic field intensity in the internal domain

0 r 0

A C

i 2 0

0

30

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