Fringing Fields for Magnetic or Electrostatic Multipoles

To third order, fringing fields for multipoles are effective only for their quadrupole- or hexapole-component. This fringing field is defined by the command: 3 F(RINGING) F(IELD) <table#> ; [example: F   F   2 ;] [F   F   1 ;]

The fringing-field integrals are taken from GIOSFF.DAT, if this mode is active; the coefficients are taken from GICOFF.DAT otherwise. Note that

• z is the coordinate along the optic axis and that
• G₀ is the aperture radius of the multipole.
• Note also that all integrals must be taken from z_a outside to z_b inside the main-field regions.