Magnetospheric wave-particle interactions near the plasmapause : experimental measurements

An experiment was performed on February 2, 1975 to measure the correlation between electron precipitation and VLF dawn chorus at Kerguelen Island. A rocket was launched to measure the X-ray bremsstrahlung from precipitating electrons. The X-ray data were compared to the record of VLF intensity in four frequency bands: 1 kHz, 2 kHz, 3 kHz, and 4 kHz with no significant correlation. Only one definable X-ray burst was found during which VLF data were available. The X-ray data were fitted to a model function and that function used to estimate the e-folding energy and the intensity of the electron spectrum. The results before and after the VLF event intensification were: before, intensity between 5 and 100 keV [approximately equals] 7 x 10[raised 9] e[raised bar]cm[raised -2]sec[raised -1]sr[raised -1] and e-folding energy 2 7.5 keV; after the VLF intensification, intensity between 5 and 100 keV [approximately equals] 10[raised 9] e[raised bar]cm[raised -2]sec[raised -1]sr[raised -1] and e-folding energy = 16 keV. The most significant result was the discrepancy between theoretical predictions and experimental results in the 5 to 10 keV X-ray energy range. Experiments indicate a large population of X-rays in this energy range while theory predicts orders of magnitude less.Physics, Department o