Enhanced radiation driven by a DC electric field

Abstract

view Abstract Citations (32) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Enhanced Radiation Driven by a DC Electric Field Tajima, T. ; Benz, A. O. ; Thaker, M. ; Leboeuf, J. N. Abstract Direct radiation by runaway electrons under a constant (dc) electric field is investigated. In a one-and-two-halves-dimensional relativistic EM code, an electron beam propagates along the external magnetic field parallel to the dc field and quickly decays into a runaway tail sustained by the dc field. Electrostatic and transverse waves are observed at various (fixed for each particular run) angles of wave propagation. Both plasma waves and EM radiation are strongly enhanced by the runaway tail. In the linear and early nonlinear beam stages, the EM wave energy is slightly enhanced as the associated electrostatic component of the waves (together with the dc field) traps and detraps electrons. In the late nonlinear (runaway) stage and with sufficiently large observing angle, bursts of EM wave energy occur, accompanied by fast perpendicular spreading of the distribution function, and they coincide with clamping of runaway electron momenta. A possible application is to msec radio spikes associated with solar flares. In this situation, the possibility of the present mechanism yielding radiation temperatures in excess of 10 to the 15th K is not out of the question. Publication: The Astrophysical Journal Pub Date: April 1990 DOI: 10.1086/168657 Bibcode: 1990ApJ...353..666T Keywords: Electric Fields; Relativistic Electron Beams; Solar Electrons; Solar Flares; Solar Radio Emission; Direct Current; Electrostatic Waves; Plasma Waves; Solar Physics; HYDRODYNAMICS; PLASMAS; RADIATION MECHANISMS; SUN: FLARES; SUN: RADIO RADIATION full text sources ADS |