Non-solar UV produced ions observed optically from the CRIT I critical velocity ionization experiment

Journal Article · Fri Jun 01 00:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA06p07749· OSTI ID:5268940

Stenbaek-Nielsen, H C; Wescott, E M ^[1]; Rees, D ^[2]; Valenzuela, A ^[3]; Brenning, N ^[4]

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1. Univ. of Alaska, Fairbanks (USA)
2. Univ. College, London (England)
3. Max Planck Institute for Extraterrestrial Physics, Garching (West Germany)
4. Royal Inst. of Tech., Stockholm (Sweden)

A critical velocity ionization experiment was carried out with a heavily instrumented rocket launched from Wallops Island at dawn on May 13, 1986. Two neutral barium beams were created by explosive shaped charges released from the rocket and detonated at 48{degree} 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 mush have been present from the time of the release and the efficiency is estimated to be equivalent to an ionization time constant of 1,800 s. The 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 {times} 10{sup {minus}18} cm{sup 2}. A critical velocity ionization process may have been present during the first few tenths of a second after release, but its efficiency cannot have exceeded an equivalent ionization time constant of about 1,800 s.

• OSTI ID: 5268940
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:A6; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARIUM
IONIZATION
IONOSPHERE
BEAM INJECTION
SOLAR SYSTEM EVOLUTION
MATHEMATICAL MODELS
ALTITUDE
COLLISIONS
CRITICAL VELOCITY
DIAGNOSTIC TECHNIQUES
EXPERIMENTAL DATA
LABORATORIES
OXYGEN
ROCKETS
SOLAR RADIATION
TESTING
ULTRAVIOLET RADIATION
VISIBLE RADIATION
ALKALINE EARTH METALS
DATA
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ELEMENTS
INFORMATION
METALS
NONMETALS
NUMERICAL DATA
PLANETARY IONOSPHERES
RADIATIONS
STELLAR RADIATION
VELOCITY
640107* - Astrophysics & Cosmology- Planetary Phenomena
640201 - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena