Schmucker-Weidelt Lecture Notes, Aarhus, 1975 - MTNet

IIence,
- I
---
"e Q -- sin (wy) e- I w ( z
I{o
and -
2 8 ' ~ ~
f--.(~) =
~ ( K ~ )
0 - j.w 1 ~5~ 1
' { ~ C+w) K
Y
- 6 ( ~ -w)} ,
Y
Elementary undulated field
-- -
tghen the source can be considered as elementary harmonic.field, as
in this case, the Fourier integral representation (2.35) cori>plicates
things only.
In the limi-k w + 0 we obtain a uniform source field in y-d.i.rection
For the induction process a strictly uniform source field is useless
since only a vertical magnetic field component induces. Hcnce w
must be non-zero, no matter how small. If we confine our attention
to a finite part of the infinite horizontal. plane, the dimensions
of that part being smaller than l/lw(, then --.- formally we may put
.w = o and can profit from the particularly simple resulting equations.
Such a source field is called a - quasi-uniform - fie1.d. To the
unrealistic uniform field belongs the source potential
which can no longer be represented in terms of (2.35)