Laboratory simulation of cometary neutral gas ionization

Journal Article · Mon May 01 04:00:00 EDT 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA05p05533· OSTI ID:5917506

Chang, Tsuey-Fen; Rahman, H U; White, R S ^[1]

---

1. Univ. of California, Riverside (USA)

The laboratory simulation of the interaction of the solar wind with a comet is used to study the cometary neutral gas ionization. The experiment is carried out in the UCR T-1 facility with an ice ball as the comet model. Photographs and data are taken with a variety of values of the solar wind velocity, interplanetary magnetic field (IMF), and comet configurations. The results show that the cometary neutral gas ionization depends on both the velocity of the solar wind and the interplanetary magnetic field. The plasma cloud surrounding the comet is visible only when the solar wind velocity and IMF are both above certain minimum values. This velocity dependent phenomena is explained by Alfven's critical ionization velocity effect. The critical magnetic field may be explained by assuming two stream lower hybrid instability as a triggering mechanism for the ionization of the neutral gas by plasma flow. Critical upper and lower limits for the magnetic field, required by anomalous ionization, are also derived that satisfy the experimental observations.

• OSTI ID: 5917506
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A5; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALFVEN WAVES
COMETS
HYDROMAGNETIC WAVES
INSTABILITY
INTERACTIONS
INTERPLANETARY MAGNETIC FIELDS
IONIZATION
LIMITING VALUES
MAGNETIC FIELDS
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
SIMULATION
SOLAR ACTIVITY
SOLAR WIND
TWO-STREAM INSTABILITY
VELOCITY