Bibliography



Found 9 entries in the Bibliography.


Showing entries from 1 through 9


2019

Particle Dynamics in the Earth\textquoterights Radiation Belts: Review of Current Research and Open Questions

The past decade transformed our observational understanding of energetic particle processes in near-Earth space. An unprecedented suite of observational systems were in operation including the Van Allen Probes, Arase, MMS, THEMIS, Cluster, GPS, GOES, and LANL-GEO magnetospheric missions. They were supported by conjugate low-altitude measurements on spacecraft, balloons, and ground-based arrays. Together these significantly improved our ability to determine and quantify the mechanisms that control the build-up and subsequent ...

Ripoll, Jean-Francois; Claudepierre, Seth; Ukhorskiy, Sasha; Colpitts, Chris; Li, Xinlin; Fennell, Joe; Crabtree, Chris;

YEAR: 2019     DOI: 10.1029/2019JA026735

inner magnetosphere; laboratory plasma experiments; Particle acceleration; particle loss; Radiation belts; Van Allen Probes

2017

Bayesian Spectral Analysis of Chorus Sub-Elements from the Van Allen Probes

We develop a Bayesian spectral analysis technique that calculates the probability distribution functions of a superposition of wave-modes each described by a linear growth rate, a frequency and a chirp rate. The Bayesian framework has a number of advantages, including 1) reducing the parameter space by integrating over the amplitude and phase of the wave, 2) incorporating the data from each channel to determine the model parameters such as frequency which leads to high resolution results in frequency and time, 3) the ability ...

Crabtree, Chris; Tejero, Erik; Ganguli, Gurudas; Hospodarsky, George; Kletzing, Craig;

YEAR: 2017     DOI: 10.1002/2016JA023547

Bayesian Spectral; Chorus; Van Allen Probes; whistler

Analysis of self-consistent nonlinear wave-particle interactions of whistler waves in laboratory and space plasmas

Whistler mode chorus is one of the most important emissions affecting the energization of the radiation belts. Recent laboratory experiments that inject energetic electron beams into a cold plasma have revealed several spectral features in the nonlinear evolution of these instabilities that have also been observed in high-time resolution in situ wave-form data. These features include (1) a sub-element structure which consists of an amplitude modulation on time-scales slower than the bounce time, (2) closely spaced discrete f ...

Crabtree, Chris; Ganguli, Gurudas; Tejero, Erik;

YEAR: 2017     DOI: 10.1063/1.4977539

Dispersion relations; Electron beams; SingingEigenvalues; Van Allen Probes; Whistler waves

2015

Nonlinear Generation of Electromagnetic Waves through Induced Scattering by Thermal Plasma

We demonstrate the conversion of electrostatic pump waves into electromagnetic waves through nonlinear induced scattering by thermal particles in a laboratory plasma. Electrostatic waves in the whistler branch are launched that propagate near the resonance cone. When the amplitude exceeds a threshold ~5 \texttimes 10-6 times the background magnetic field, wave power is scattered below the pump frequency with wave normal angles (~59\textdegree), where the scattered wavelength reaches the limits of the plasma column. The scatt ...

Tejero, E.; Crabtree, C.; Blackwell, D.; Amatucci, W.; Mithaiwala, M.; Ganguli, G.; Rudakov, L.;

YEAR: 2015     DOI: 10.1038/srep17852

Magnetically confined plasmas; Magnetospheric physics

Evolution of lower hybrid turbulence in the ionosphere

Three-dimensional evolution of the lower hybrid turbulence driven by a spatially localized ion ring beam perpendicular to the ambient magnetic field in space plasmas is analyzed. It is shown that the quasi-linear saturation model breaks down when the nonlinear rate of scattering by thermal electron is larger than linear damping rates, which can occur even for low wave amplitudes. The evolution is found to be essentially a three-dimensional phenomenon, which cannot be accurately explained by two-dimensional simulations. An im ...

Ganguli, G.; Crabtree, C.; Mithaiwala, M.; Rudakov, L.; Scales, W.;

YEAR: 2015     DOI: 10.1063/1.4936281

Ionosphere

Laboratory studies of nonlinear whistler wave processes in the Van Allen radiation belts

Important nonlinear wave-wave and wave-particle interactions that occur in the Earth\textquoterights Van Allen radiation belts are investigated in a laboratory experiment. Predominantly electrostatic waves in the whistler branch are launched that propagate near the resonance cone with measured wave normal angle greater than 85\textdegree . When the pump amplitude exceeds a threshold \~5\texttimes10-6 times the background magnetic field, wave power at frequencies below the pump frequency is observed at wave normal angles (\~5 ...

Tejero, E.; Crabtree, C.; Blackwell, D.; Amatucci, W.; Mithaiwala, M.; Ganguli, G.; Rudakov, L.;

YEAR: 2015     DOI: 10.1063/1.4928944

Nonlinear waves; Van Allen Belts

Laboratory studies of nonlinear whistler wave processes in the Van Allen radiation belts

Important nonlinear wave-wave and wave-particle interactions that occur in the Earth\textquoterights Van Allen radiation belts are investigated in a laboratory experiment. Predominantly electrostatic waves in the whistler branch are launched that propagate near the resonance cone with measured wave normal angle greater than 85\textordmasculine. When the pump amplitude exceeds a threshold ~5 x10^6 times the back- ground magnetic field, wave power at frequencies below the pump frequency is observed at wave normal angles (~55\t ...

Tejero, E.; Crabtree, C.; Blackwell, D.; Amatucci, W.; Mithaiwala, M.; Ganguli, G.; Rudakov, L.;

YEAR: 2015     DOI: 10.1063/1.4928944

Electrostatic Waves; magnetic fields; Nonlinear scattering; Plasma electromagnetic waves; Whistler waves

2014

Generation of electromagnetic waves in the very low frequency band by velocity gradient

It is shown that a magnetized plasma layer with a velocity gradient in the flow perpendicular to the ambient magnetic field is unstable to waves in the Very Low Frequency band that spans the ion and electron gyrofrequencies. The waves are formally electromagnetic. However, depending on wave vector k⎯⎯=kc/ωpe (normalized by the electron skin depth) and the obliqueness, k⊥/k|| , where k⊥,|||| are wave vectors perpendicular and parallel to the magnetic field, the waves are closer to electrostatic in nature when k⎯⎯ ...

Ganguli, G.; Tejero, E.; Crabtree, C.; Amatucci, W.; Rudakov, L.;

YEAR: 2014     DOI: 10.1063/1.4862032

Electromagnetic wave

2012

Weak turbulence in the magnetosphere: Formation of whistler wave cavity by nonlinear scattering

We consider the weak turbulence of whistler waves in the in low-β inner magnetosphere of the earth. Whistler waves, originating in the ionosphere, propagate radially outward and can trigger nonlinear induced scattering by thermal electrons provided the wave energy density is large enough. Nonlinear scattering can substantially change the direction of the wave vector of whistler waves and hence the direction of energy flux with only a small change in the frequency. A portion of whistler waves return to the ionosphere with a ...

Crabtree, C.; Rudakov, L.; Ganguli, G.; Mithaiwala, M.; Galinsky, V.; Shevchenko, V.;

YEAR: 2012     DOI: 10.1063/1.3692092

Whistler waves; Magnetosphere



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