A STUDY OF AURORAL X-RAYS AT MINNEAPOLIS BETWEEN 23 AUGUST 1959 AND 1 AUGUST 1960

Technical Report · Sat Apr 01 04:00:00 EST 1961

OSTI ID:4051784

May, T C

The auroral x-ray occurrences detected by a balloon monitoring project between August 23, 1959 and August 1, 1960 are presented. The standard monitoring flight train consisted of a four-component detector unit, a pressuremeasuring and cutdown timer device, a VHF transmitter with two FM--FM subcarriers, and an emulsion stack. Calculations of detector efficiencies to photons were made and these efficiencies used to explain experimental ratios of rates of the detectors to various photon spectra. Timerate curves of the flights on which there were auroral x rays and magnetometer records of the earth's field are presented. During the time interval the magnetometer was operated 8050 hr. For a total of 134 hr the magnetometer deviated more than 100 gamma 's negative. About 83% of the 134 hr were within the 12 hr centered at local midnight. The negative excursions occurred on days of magnetic storms. Of the time the magnetometer was more than 100 gamma 's negative, there was a balloon at ceiling, with all of the detectors working, 38.5 hr. X rays were detected 64% of the time. On the other hand, there was a balloon at ceiling 447 hrs when the magnetometer was quiet and x rays occurred less than 1% of the time. Calculations are presented which show that the electron flux distribution which causes auroral x rays is much more intense at low energies than at high energies. Calculations were also made of the average electron flux above 20 kev for each burst, assuming that the flux distribution was of the form kE/sup -//sup 3/ and that the electrons were impinging on the top of the atmosphere over a large area above the balloon. Laboratory experiments which verified most of the procedures used in the calculations are discussed. The possible magnetic effects of the bremsstrahlung-producing electrons were also studied. (M.C.G.)

• Research Organization: Minnesota. Univ., Minneapolis. School of Physics
• NSA Number: NSA-15-020946
• OSTI ID: 4051784
• Report Number(s): NP-10290; CR-36
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AURORAE
BALLOONS
BREMSSTRAHLUNG
DISTRIBUTION
EARTH
EFFICIENCY
ELECTRON BEAMS
ELECTRONIC EQUIPMENT
ENERGY
GEOLOGY, MINERALOGY, AND METEOROLOGY
GEOPHYSICS
MAGNETIC FIELDS
MAGNETOMETERS
MEASURED VALUES
MONITORING
NUCLEAR EMULSIONS
PHOTONS
PRESSURE
QUANTITATIVE ANALYSIS
RADIATION DETECTORS
RECORDING SYSTEMS
SPECTRA
X RADIATION