Broad injection front, not a narrow sector. Common understanding had been a narrow Local Time Injection.
All energies drift at a rate consistent with injection at about L = 7RE;
6 hr drift period @ 22 keV
3 hr drift period @ 45 keV
<---- ~1.5 hours, 22 keV ----->
<---- ~0.75 hours, 45 keV ----->
360 Degree Drift Period as a function of Energy, L
Figure adapted from Shultz & Lanzerotti, 1974
Energetic Neutral Atom Images IMAGE/HENA, 6/10/00