No abstract available

[en] To understand auroral phenomena and associated magnetospheric processes, balloon-borne measurements of bremsstrahlung X rays produced by electrons precipitating in our atmosphere have been made by various scientists. Measurements made by balloon-borne payloads have an advantage over direct measurements of electrons by satellites or rockets as these measurements provide an intense coverage at one location. These observations are usually made between 30-35 km altitude, and to relate them to the parent electron flux at the top of the atmosphere, it is necessary to understand the effect of propagation of X rays through the terrestrial atmosphere from ∼ 100 km to the detection altitude (∼ 30 km)

[en] The paper describes balloon observations of bremsstrahlung X-rays carried out by the University of Calgary over the past decade which deal with morphological studies of auroral electron precipitation. The program concentrated on the understanding of the correlation between parent electrons and secondary X-rays, the study of microbursts, east-west and north-south extent of electron precipitation, and precipitation during pulsating auroras

[en] From incoherent scatter data colleced at the Arecibo Observatory from 1965 to 1968 a comparison was made between measured values of nighttime F-region electron and ion temperature and the plasma temperature inferred from the topside scale height of the measured electron concentration profile. It was found that these temperatures agreed to within a few per cent, implying that the exospheric temperature can be obtained with reasonable accuracy by either method. Caution must be exercised in applying this conclusion to othe latitudes and times because of the restrictive conditions required. These conditions are discussed briefly. (author)

[en] Simultaneous measurements of the energy spectrum of precipitating electrons and the resulting bremsstrahlung X ray spectrum were carried out during an auroral event on March 3, 1971, at the Churchill Research Range, Manitoba, Canada. The electron data were obtained with detectors on a Black Brant VB sounding rocket (275-km apogee), while the X ray flux was measured by an instrument package that was boosted to 60 km on an Arcas rocket. The X ray package was deployed on a parachute at apogee to provide a slow descent through the atmosphere. Thick target bremsstrahlung theory is used to calculate the X ray flux produced by the incident electrons, and a Monte Carlo method is used to predict the X ray spectrum at various altitudes appropriate for comparison with the measured X ray data. Satisfactory agreement between theory and experiment is obtained, and the value of the constant in the thick target theory has been estimated to be (2plus-or-minus0.5) times10^-5

[en] Simultaneous measurements of the energy spectrum of precipitating electrons and the resulting bremsstrahlung X ray spectrum were carried out during an auroral event on March 3, 1971, at the Churchill Research Range, Manitoba, Canada. The electron data were obtained with detectors on a Black Brant VB sounding rocket (275-km apogee), while the X ray flux was measured by an instrument package that was boosted to 60 km on an Arcas rocket. The X ray package was deployed on a parachute apogee to provide a slow descent through the atmosphere. Thick target bremsstrahlung theory is used to calculate the X ray flux produced by the incident electrons, and a Monte Carlo method is used to predict the X ray spectrum at various altitudes appropriate for comparison with the measured X ray data. Satisfactory agreement between theory and experiment is obtained, and the value of the constant in the thick target theory has been estimated to be (2plus-or-minus0.5) times10^-5. (auth)