Balloon observations of auroral x-rays in Canada, (1)

Two balloons each carrying a payload consisting of three sets of NaI (Tl) scintillation counters have been launched from Thompson, Manitoba, Canada, in April 1975, to search precipitating mechanisms of auroral particles through observations of the bremsstrahlung X-rays in conjugation with the geo-stationary satellite ATS-6. Two omnidirectional counters, one of which had the modulation collimator, were used together with the directional counter inclined from the zenith. On the basis of the spin-modulated data obtained during the appearance of two distinct auroral X-ray bursts, two-dimensional source models, arc- and disc-shaped, are proposed for the auroral X-ray illuminating region. Also shown is an example of the eastward drift of another auroral X-ray source. Some of problems related to the analyses of data, i.e., background fluxes due to cosmic rays, and the response functions of the detectors are discussed. (author)