Counts as a function of the angle between the magnetic field and the normal to the M’. The dashed line joins adjacent sectors, that is, marks the progression in time from sector to sector and is a model curve obtained from Monte Carlo simulations of the detector response for field aligned protons. (left) Model versus observation for P’2 measures, 2 min integration around 02:09:41 UT. (right) Model versus observation for P’8 measures, 10 minute integration after 02:09:41 UT.