Reverse current in solar flares

Technical Report · Tue Aug 01 00:00:00 EDT 1978

OSTI ID:6331459

Knight, III, J W

An idealized steady state model of a stream of energetic electrons neutralized by a reverse current in the pre-flare solar plasma was developed. These calculations indicate that, in some cases, a significant fraction of the beam energy may be dissipated by the reverse current. Joule heating by the reverse current is a more effective mechanism for heating the plasma than collisional losses from the energetic electrons because the Ohmic losses are caused by thermal electrons in the reverse current which have much shorter mean free paths than the energetic electrons. The heating due to reverse currents is calculated for two injected energetic electron fluxes. For the smaller injected flux, the temperature of the coronal plasma is raised by about a factor of two. The larger flux causes the reverse current drift velocity to exceed the critical velocity for the onset of ion cyclotron turbulence; anomalous resistivity and an order-of-magnitude increase in the temperature result. The heating is so rapid that the lack of ionization equilibrium may produce a soft X-ray and EUV pulse from the corona.

• Research Organization: Stanford Univ., CA (USA). Inst. for Plasma Research
• DOE Contract Number: NGL-05-020-272; N00014-75-C-0673
• OSTI ID: 6331459
• Report Number(s): N-78-31031; TRN: 79-012623
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SOLAR CORONA
JOULE HEATING
SOLAR FLARES
ELECTRIC CURRENTS
EXTREME ULTRAVIOLET RADIATION
FLUX DENSITY
ICR HEATING
MATHEMATICAL MODELS
PULSES
SOFT X RADIATION
SOLAR ELECTRONS
SOLAR WIND
CURRENTS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HEATING
HIGH-FREQUENCY HEATING
IONIZING RADIATIONS
LEPTONS
PLASMA HEATING
RADIATIONS
SOLAR ACTIVITY
SOLAR PARTICLES
SOLAR RADIATION
STELLAR RADIATION
ULTRAVIOLET RADIATION
X RADIATION
640104* - Astrophysics & Cosmology- Solar Phenomena