Electric and magnetic field measurements inside a high-velocity neutral beam undergoing ionization

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA00442· OSTI ID:5222328

Kelley, M C; Swenson, C M ^[1]; Brenning, N ^[2]; Baker, K ^[3]; Pfaff, R ^[4]

---

1. Cornell Univ., Ithaca, NY (USA)
2. Royal Inst. of Tech., Stockholm (Sweden)
3. Utah State Univ., Logan (USA)
4. NASA Goddard Space Flight Center, Greenbelt, MD (USA)

Vector electric field measurements have been made inside two ionizing, high-velocity streams of barium atoms in the Earth's ionosphere. A variety of electrical phenomena were observed across the frequency spectrum and are presented in this paper, which emphasizes the experimental results. A most startling result is that a very large quasi-dc electric field was detected antiparallel to the beam velocity. This by itself is not unreasonable since newly ionized barium ions with their large gyroradii are expected to create such a field. But since the beam had roughly a 45 {degree} angle with the magnetic field, B{sub o}, the authors find a very large ({approx gt} 500 mV/m) component of E parallel to B{sub o}. The fluctuating electric fields were also quite large, in fact, of the same order of magnitude as the quasi-dc pulse. The wave energy was found to maximize at frequencies below the barium lower hybrid frequency and included strong signatures of the oxygen cyclotron frequency. Measurements made on a subpayload separated across B{sub o} by several hundred meters and along B{sub o} by several kilometers do not show the large pulse, although a variety of wave emissions were seen. In addition, very large amplitude magnetic field fluctuations were detected in both bursts. Although they have no clear explanation, they appear to be real phenomenon and worthy of future study. Finally, they note that even though the critical ionization velocity effect did not go into a discharge mode in this experiment, remarkable electromagnetic effects were seen in the neutral beam-plasma interaction.

• OSTI ID: 5222328
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A6; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METALS
ATOMS
BARIUM
BARIUM IONS
BEAM-PLASMA SYSTEMS
CHARGED PARTICLES
COMPARATIVE EVALUATIONS
DATA
DIAGNOSTIC TECHNIQUES
EARTH ATMOSPHERE
ELECTRIC FIELDS
ELEMENTS
EVALUATION
INFORMATION
IONIZATION
IONOSPHERE
IONS
MAGNETIC FIELDS
MATHEMATICAL MODELS
METALS
PLANETARY IONOSPHERES