Assertion: magnetic field's field line | /r/HasProperty | confined by the core
Facets:
value: in the gaps
type: LOCATION
value: no longer
type: TEMPORAL
Source sentences:
text: In the gaps the magnetic field lines are no longer confined by the core, so they 'bulge' out beyond the outlines of the core before curving back to enter the next piece of core material, reducing the field strength in the gap.