Measurements of precipitated 1-20 kev protons and electrons during a breakup aurora

Measurements of precipitating low energy (1-20 keV) prutu a and electrons during a breakup aurora are described.The observed proton fluxes were as high aei lU b cm -2 sec -1 keV -1 str -1 with an e-fold energy of 1 keV; the electron fluxes were AC 8 cm-2 sec-1 keV -1 str -1 with a spectral peak fit the 2-4 keV region.During the flight, the rocket passed through the poleward boundary of thR auroral form.One in-erpretation of the data suggests that the proton and 2.5 keV electron precipitation boundaries coincided LI with.n a distance of -1 ks; the lower energy electron boundary extended 4everal kilometers poleward of the proton boundary.Evidence for nun-isotropic proton fluw:es is presented.