Relativistic electromagnetic instabilities near electron cyclotron frequency and harmonics

Conference · Thu Mar 01 04:00:00 EST 1984

OSTI ID:5089349

Ram, A K; Francis, G; Bers, A

We present the linear evolution in space-time of electromagnetic instabilities generated by relativistic beam-type electron distribution functions that characterize highly anisotropic electron plasmas. The plasma is assumed to be infinite, homogeneous and in a static, uniform magnetic field (antiB/sub 0/). For waves propagating along antiB/sub 0/ there are two absolute instabilities - the Whistler and the relativistic instability - both near the electron cyclotron frequency (omega/sub c/). For waves propagating perpendicular to antiB/sub 0/ instabilities occur at omega/sub c/ and its harmonics. At low densities the instability at omega/sub c/ is absolute and has the highest growth rate, while those at higher harmonics are convective and have lower growth rates. As the density is increased the instabilities at omega/sub c/ and 2omega/sub c/ are absolute. Further increase in the density leads to the instability at omega/sub c/ becoming convective and that at 2omega/sub c/ remaining absolute. The detailed observation of unstable radiation from such plasmas could lead to an estimate of the hot density component of the plasma. In another context, gyrotron-type devices could conceivably be built for generating electromagnetic energy at harmonics of omega/sub c/.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Plasma Fusion Center
• DOE Contract Number: AC02-78ET51013
• OSTI ID: 5089349
• Report Number(s): DOE/ET/51013-118; PFC/CP-84-5; CONF-840391-1; ON: DE84009672
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
BEAM-PLASMA SYSTEMS
CYCLOTRON FREQUENCY
CYCLOTRON INSTABILITY
DISTRIBUTION FUNCTIONS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
FUNCTIONS
HARMONICS
INSTABILITY
INSTABILITY GROWTH RATES
LEPTONS
OSCILLATIONS
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
RADIATIONS