Nonlinear plasma maser driven by electron beam instability

Abstract

The detailed analysis of plasma maser interaction between high-frequency electromagnetic waves with right-handed polarization (R mode) and electrostatic Langmuir waves excited by an electron beam is presented. The analysis shows that generation of R-mode radiation near 2ωpe is possible only for magnetized plasmas; here ωpe is the electron plasma frequency. Simulations using a two-dimensional electromagnetic and relativistic particle code show that high-frequency electromagnetic waves with right-handed polarization (R mode) can be generated by a plasma maser mechanism from electrostatic Langmuir waves excited by an electron beam.

Simulations of electron/electron instabilities: Electromagnetic fluctuations

“…The recent simulations of Nambu et al, 13 although restricted to e у 3, show that a decreasing e leads to significant enhancements of electromagnetic field fluctuations associated with a basically electrostatic electron/electron instability. So ␤ ʈc and e are two of the most important parameters in determining the electromagnetic properties of these growing modes.…”

“…Newman et al 11 and Winglee et al 12 considered initially anisotropic electron beams which excited the intrinsically electromagnetic electron anisotropy instability. Yin et al, 9 Newman et al, 11 and Nambu et al 13 considered only e Ͼ 1 where ͑as we shall demonstrate͒ electromagnetic effects of the electron/electron beam instability are relatively weak.…”

Electromagnetic fluctuations near the electron plasma frequency from an electron/electron instability

“…instability can account for the first three properties of the magnetospheric observations cited above. Previous electromagnetic simulations of these instabilities did not address this problem either because they considered only r/e > 1 [Newman et al, 1988;Yin et al, 1998;Nambu et al, 1999] or because they assumed a large anisotropy on the beam, thereby exciting fundamentally electromagnetic instabilities [Omura and Matsumoto, 1987 (Figure 4). In addition, the present simulations provide new information about the late-time dispersion of the fluctuations (Figure 3) and show that right handedness is more likely to arise at short wavelengths, whereas left handedness predominates at longer wavelengths ( Figure 5).…”

Study of plasma–maser instability in an inhomogeneous plasma

“…Since the prediction of this new nonlinear wave particle interaction process, there has been an increasing interest in 1 Permanent address: Department of Mathematics, Namrup College, Namrup, Assam 786623, India. theoretical, experimental and observational studies [8][9][10] of the plasma-maser effect. This mode-mode coupling process has been applied to auroral kilometric radiation, type III radio emission, chorus-related electrostatic bursts, Jovian kilometric radiation and Saturnian kilometric radiation.…”