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Non-solar UV produced ions observed optically from the 'Crit I' critical velocity ionization experimentA critical velocity ionization experiment was carried out with a heavily instrumented rocket launched from Wallops Island on May 13, 1986. Two neutral barium beams were created by explosive shaped charges released from the rocket and detonated at 48 deg to B at altitudes near 400 km and below the solar UV cutoff. Critical velocity ionization was expected to form a detectable ion jet along the release field line, but, instead, an ion cloud of fairly uniform intensity was observed stretching from the release field line across to where the neutral barium jet reached sunlight. The process creating these ions must have been present from the time of the release; the efficiency is estimated to be equivalent to an ionization time constant of 1800 sec. This ionization is most likely from collisions between the neutral barium jet and the ambient atmospheric oxygen, and, if so, the cross section for collisional ionization is 9 x 10 to the -18th sq cm.
Document ID
19900049903
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Stenbaek-Nielsen, H. C.
(Alaska Univ. Fairbanks, AK, United States)
Wescott, E. M.
(Alaska, University Fairbanks, United States)
Rees, D.
(University College London, United Kingdom)
Valenzuela, A.
(Max-Planck-Institut fuer extraterrestrische Physik Federal Republic of Germany, United States)
Brenning, N.
(Kungliga Tekniska Hogskolan Stockholm, Sweden)
Date Acquired
August 14, 2013
Publication Date
June 1, 1990
Publication Information
Publication: Journal of Geophysical Research
Volume: 95
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
90A36958
Funding Number(s)
CONTRACT_GRANT: NAG6-1
CONTRACT_GRANT: NAGW-269
Distribution Limits
Public
Copyright
Other

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