Overlapping of the harmonics of the cyclotron frequency in the Bernstein waves due to relativistic effects

2018 ◽  
Vol 25 (10) ◽  
pp. 102103 ◽  
Author(s):  
Waseem Khan ◽  
Muddasir Ali ◽  
Zafar Iqbal ◽  
Gohar Abbas ◽  
Zahida Ehsan
Keyword(s):  
Cyclotron Frequency ◽  
Relativistic Effects ◽  
Bernstein Waves

Dispersion of electron Bernstein waves including weakly relativistic and electromagnetic effects. Part 2. Extraordinary modes

1987 ◽  
Vol 37 (3) ◽  
pp. 449-465 ◽  
Author(s):  
P. A. Robinson
Keyword(s):  
Uniform Magnetic Field ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Relativistic Effects ◽  
Companion Paper ◽  
Hybrid Frequency ◽  
Maxwellian Plasma ◽  
Small Wave ◽  
Bernstein Waves ◽  
Plasma Theory

Extraordinary solutions of the weakly relativistic, electromagnetic dispersion relation are investigated for waves propagating perpendicular to a uniform magnetic field in a Maxwellian plasma. As in a companion paper, which treated ordinary modes, weakly relativistic effects are found to modify dramatically the dispersion predicted by strictly non-relativistic ‘classical’ theory in the neighbourhood of harmonics of the cyclotron frequency Ωe. The infinite families of classical Gross–Bernstein and Dnestrovskii–Kostomarov modes are truncated to include only harmonics s satisfying s ≲ (ω2p mc2/4kB TΩ2e)⅓ and s ≲(ωp/Ωe)⅔/8 respectively where ωp is the plasma frequency and T the temperature. All classical cut-offs and resonances are removed apart from the x– and z– mode cut-offs. The only coupling between large- and small-wave-vector modes is between the z mode and a Gross–Bernstein mode near the upper-hybrid frequency and between the x mode and the second Gross–Bernstein mode near 2Ωe. Dispersion of the weakly relativistic counterpart of the x mode departs only slightly from that predicted by cold plasma theory except near Ωe and 2Ωe.

scholarly journals A Brief Analysis of the Research Scheme of the Cyclotron Radiation from a Single Electron

2019 ◽  
Author(s):  
Jian Ding
Keyword(s):  
Electromagnetic Radiation ◽  
High Speed ◽  
Cyclotron Frequency ◽  
Relativistic Effects ◽  
Physical Constant ◽  
Single Electron ◽  
Main Body ◽  
Mass Ratio ◽  
De Broglie Wavelength ◽  
Electromagnetic Radiations

The experiments of Project 8 have been excellent, but the expected goals still difficult to achieve. So much so that some of the results at your fingertips were also missing. In view of this, the focus of this article is to clarify several easy confused concepts. Only in this way, we can reasonably explain the experimental data. The main points are as follows: 1. The value c of the light speed in vacuum and a particle with zero static mass, both of which do not exist in the reality. That is to say, the so-called a photon's static mass is equal to zero but has energy, which is a paradox that confuses two different definitional domains. 2. In the reality, photons are high-speed particles generated by electromagnetic radiation. They must have the characteristics of (static) mass, energy and wave, in order to describe the main body to aim at photons from different angles. 3. After any main body comes into being electromagnetic radiation, its static mass will inevitably decrease accordingly. 4. The charge-mass ratio of an electron is a physical constant, which is the ratio of its charge to the amount of matter, and is not affected by relativistic effects and electromagnetic radiation. 5. The uncertainty of moving electrons is caused by random electromagnetic radiations. Finally, it is pointed out that if the cyclotron frequency of a single electron is measured, and at the same time, its de Broglie wavelength or frequency can also be measured, then its static mass can be obtained. Even so, the expected goals are still difficult to achieve, because random electromagnetic radiations are always taking away continually the matter composition of the single electron being measured. However, this was precisely a result of the research obtained by Project 8, and had universality, which should be reflect on.

Electrostatic waves in the shock ramp and their effect on plasma energetics.

2021 ◽  
Author(s):  
Ahmad Lalti ◽  
Yuri Khotyaintsev ◽  
Daniel Graham ◽  
Andris Vaivad ◽  
Andreas Johlander
Keyword(s):  
Solar Wind ◽  
Acoustic Waves ◽  
Cyclotron Frequency ◽  
Particle Interactions ◽  
Ion Acoustic Waves ◽  
Electrostatic Waves ◽  
Ion Plasma ◽  
Magnetospheric Multiscale ◽  
Bernstein Waves ◽  
Open Question

<p>Energy dissipation at collisionless shocks is still an open question. Wave particle interactions are believed to be at the heart of it, but the exact details are still to be figured out. One type of waves that is known to be an efficient dissipator of solar wind kinetic energy are electrostatic waves in the shock ramp, such as ion acoustic waves with frequency around the ion plasma frequency or Bernstein waves with frequency around the electron cyclotron frequency and its harmonics. The electric field of such waves is typically larger than 100 mV/m, large enough to disturb particle dynamics. In this study we use the magnetospheric multiscale (MMS) spacecraft, to investigate the source and evolution of electrostatic waves in the shock ramp of quasi-perpendicular super-critical shocks, and study their effect on solar wind thermalization.</p>

scholarly journals Two-stream instabilities from the lower-hybrid frequency to the electron cyclotron frequency: application to the front of quasi-perpendicular shocks

2017 ◽  
Vol 35 (5) ◽  
pp. 1093-1112 ◽  
Author(s):  
Laurent Muschietti ◽  
Bertrand Lembège
Keyword(s):  
Shock Front ◽  
Cyclotron Frequency ◽  
Ion Beam ◽  
Wide Frequency Range ◽  
Electron Cyclotron ◽  
Lower Hybrid ◽  
Bernstein Waves ◽  
Synthetic View ◽  
Drift Instability ◽  
The Waves

Abstract. Quasi-perpendicular supercritical shocks are characterized by the presence of a magnetic foot due to the accumulation of a fraction of the incoming ions that is reflected by the shock front. There, three different plasma populations coexist (incoming ion core, reflected ion beam, electrons) and can excite various two-stream instabilities (TSIs) owing to their relative drifts. These instabilities represent local sources of turbulence with a wide frequency range extending from the lower hybrid to the electron cyclotron. Their linear features are analyzed by means of both a dispersion study and numerical PIC simulations. Three main types of TSI and correspondingly excited waves are identified: i. Oblique whistlers due to the (so-called fast) relative drift between reflected ions/electrons; the waves propagate toward upstream away from the shock front at a strongly oblique angle (θ ∼ 50°) to the ambient magnetic field Bo, have frequencies a few times the lower hybrid, and have wavelengths a fraction of the ion inertia length c∕ωpi. ii. Quasi-perpendicular whistlers due to the (so-called slow) relative drift between incoming ions/electrons; the waves propagate toward the shock ramp at an angle θ a few degrees off 90°, have frequencies around the lower hybrid, and have wavelengths several times the electron inertia length c∕ωpe. iii. Extended Bernstein waves which also propagate in the quasi-perpendicular domain, yet are due to the (so-called fast) relative drift between reflected ions/electrons; the instability is an extension of the electron cyclotron drift instability (normally strictly perpendicular and electrostatic) and produces waves with a magnetic component which have frequencies close to the electron cyclotron as well as wavelengths close to the electron gyroradius and which propagate toward upstream. Present results are compared with previous works in order to stress some features not previously analyzed and to define a more synthetic view of these TSIs.

Dispersion of electron Bernstein waves including weakly relativistic and electromagnetic effects. Part 1. Ordinary modes

1987 ◽  
Vol 37 (3) ◽  
pp. 435-447 ◽  
Author(s):  
P. A. Robinson
Keyword(s):  
Dispersion Relation ◽  
Uniform Magnetic Field ◽  
Cold Plasma ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Infinite Family ◽  
Companion Paper ◽  
Maxwellian Plasma ◽  
Bernstein Waves ◽  
Plasma Theory

Ordinary solutions of the weakly relativistic, electromagnetic dispersion relation are investigated for waves propagating perpendicular to a uniform magnetic field in a Maxwellian plasma. Weakly relativistic resonance broadening, frequency downshift and damping are found to alter dramatically the dispersion predicted by the corresponding strictly non-relativistic (‘classical’) theory in the neighbourhood of harmonics of the cyclotron frequency Ωe. All classical resonances and cut-offs are removed except the cut-off at the plasma frequency ωp. At frequencies above ωp the infinite family of classically predicted modes is replaced by a single weakly damped mode whose dispersion differs only slightly from that predicted by cold plasma theory. No weakly damped modes exist in the range of harmonics s satisfying (ωp/Ωe)⅔/8 ≲ S < Ωp/Ωe, however, one such mode is located immediately below each harmonic for s ≲ (ωp/Ωe)⅔/8. A companion paper investigates extraordinary solutions of the dispersion relation.

scholarly journals A brief analysis of the research scheme of the cyclotron radiation from a single electron

2019 ◽  
Author(s):  
Jian DING
Keyword(s):  
Electromagnetic Radiation ◽  
High Speed ◽  
Cyclotron Frequency ◽  
Relativistic Effects ◽  
Physical Constant ◽  
Single Electron ◽  
Main Body ◽  
Mass Ratio ◽  
De Broglie Wavelength ◽  
Electromagnetic Radiations

The experiments of Project 8 have been excellent, but the expected goals still difficult to achieve. So much so that some of the results at your fingertips were also missing. In view of this, the focus of this article is to clarify several easy confused concepts. Only in this way, we can reasonably explain the experimental data. The main points are as follows: 1. The value c of the light speed in vacuum and a particle with zero static mass, both of which do not exist in the reality. That is to say, the so-called a photon's static mass is equal to zero but has energy, which is a paradox that confuses two different definitional domains. 2. In the reality, photons are high-speed particles generated by electromagnetic radiation. They must have the characteristics of (static) mass, energy and wave, in order to describe the main body to aim at photons from different angles. 3. After any main body comes into being electromagnetic radiation, its static mass will inevitably decrease accordingly. 4. The charge-mass ratio of an electron is a physical constant, which is the ratio of its charge to the amount of matter, and is not affected by relativistic effects and electromagnetic radiation. 5. The uncertainty of moving electrons is caused by random electromagnetic radiations. Finally, it is pointed out that if the cyclotron frequency of a single electron is measured, and at the same time, its de Broglie wavelength or frequency can also be measured, then its static mass can be obtained. Even so, the expected goals are still difficult to achieve, because random electromagnetic radiations are always taking away continually the matter composition of the single electron being measured. However, this was precisely a result of the research obtained by Project 8, and had universality, which should be reflect on.

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