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Fringing fields for magnetic sector fields are defined by the command:
5 F(RINGING) F(IELD) <table#>
<entrance or exit angle
in degrees>
<curvature
of effective field boundary> ;
[example: F F 2 10.0 1.0 0.4853 ;]
[F F 1 0 0 ;] .
The fringing-field integrals are taken from GIOSFF.DAT, if this mode
is active; the coefficients are taken from GICOFF.DAT otherwise.
Note that
-
is a coordinate perpendicular to the effective field boundary,
- G0 is the half air gap,
- the integral I5 must be taken from
to the effective
field boundary, i.e. to
=0,
- and the integrals I1 and I2 must be taken from
outside to
inside the main-field region.
Note that
(see Fig. 4.8 in Ref. 7)
is positive if the normal to the field boundary is
further away from the center of curvature of the optic axis than the
incoming or outgoing beam. Note further, that
(see Fig. 8.6 in Ref. 7) is positive for a convex
field boundary and negative for a concave one.
KPII
1999-10-20