Explorer XXXI total current monitor experiments

Measurements have been made of the suprathermal electron flux by means of retarding potential analyzers on Explorer XXXI. Samples of various types of data are presented and some of the analysis procedures are discussed. Detailed analyses of particle flux measurements obtained in the energy range 7 eV to 200 eV are presented for the data from three spacecraft transits of the polar region. The integral flux and derived differential velocity distributions yield the result that in the polar trough region there is an enhanced energy density of the suprathermal particles, with a value comparable to that of the ambient thermal plasma. At lower latitudes, the pressure of suprathermal particles is significantly less than that of the thermal plasma.