Accession Number : AD0660196

Title :   MICROBURST PHENOMENA. I. AURORAL ZONE X-RAYS,

Corporate Author : IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Oliven,N. M. ; Venkatesan,D. ; Edwards,P. J. ; McCracken,K. G. ; Steinbock,M.

Report Date : SEP 1967

Pagination or Media Count : 40

Abstract : High-time resolution x-ray equipment flown from Ft. Churchill, Manitoba, Canada on August 11, 1965 provides evidence for species of auroral zone x-ray microbursts with an asymmetric time profile. These asymmetric microbursts are characterized by a rise of the form 1 - e to the power (-t/tau sub R) where tau sub R is about 30 milliseconds, and a decay of the form of e to the power (-t/tau sub D) where tau sub D is about 200 milliseconds, and a typical peak flux for the largest events of Jo (Ex-ray > 60 keV) of about 100 photons/cm squared sec at 10 g/sq. cm. An episode of these asymmetric bursts was observed in the early morning hours (after 4:30 local time) and an episode of the more common symmetric microbursts began after 9:30 local time. The fast rise times, and the lack of dispersion approximately = or > 10 milliseconds in the x-ray bursts observed at different energies implies restrictions on the nature, and propagation of the parent electron microbursts. (Author)

Descriptors :   (*X RAYS, POLAR REGIONS), CANADA, BREMSSTRAHLUNG, BALLOONS, ATMOSPHERIC SOUNDING, UPPER ATMOSPHERE, ELECTRONS, GEOMAGNETISM, AURORAE, RADIATION MEASURING INSTRUMENTS, MAGNETOSPHERE

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE