Laboratory observations of RF emissions at ωpeand (n+ ½)ωcein Electron beam-plasma and beam-beam interactions

Bernstein, W.; Leinbach, H.; Cohen, H. A.; Wilson, P. S.; Davis, T. N.; Hallinan, T. J.; Baker, Bob; Martz, Joseph C.; Zeimke, R.; Huber, W.

doi:10.1029/ja080i031p04375

Cited by 55 publications

(11 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As part of just such a plan involving a continuing investigation of large-facility beam-plasma interactions (Bernstein, et al, 1975(Bernstein, et al, , 1977(Bernstein, et al, , 1978 the Naval Research Laboratory (NRL) participated in a recent series of experiments at the NASA Johnson Space Center (JSC). The NRL contribution involved the direct measurement of electron density and temperature under varying conditions of beam-plasma and neutral gas parameters.…”

Section: Introductionmentioning

confidence: 99%

“…tA MONITORING AGENCY NAME I ADDRES S (Il dSll.c.u - As part of just such a plan involving a continuing investigation of large-facility beam-plasma interactions ( Bernstein , et al , 1975( Bernstein , et al , ,1977( Bernstein , et al , ,1978 the Naval Research tile "beam-plasma-discharge" (Getty and Smullin, 1963;Bernstein et al,1978). The observed density profile is found to be in good agreement with a two-dimensional diffusion model and this result makes possible the first estimate for the cross-field electron diffusion coefficient in a large facility BPD.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Plasma diffusion in a space‐simulation beam‐plasma‐discharge

Szuszczewicz¹,

Walker²,

Holmes³

et al. 1979

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

Electron density and temperature profiles have been measured in a large‐facility beam‐plasma‐discharge (VB = 1.3 KeV, IB = 63 ma) at low pressure (P = 2‐4 (10−6)Torr) and low magnetic fields (B = 1.2 G). The results follow an exponential behavior and are found to be in good agreement with a simple diffusion model. The favorable comparison between theory and experiment yields the first estimate of cross‐field electron diffusion (De⊥(nom) = 2.2(106) cm²/sec) under conditions intended to simulate Spacelab‐borne beam‐plasma investigations. This value for De⊥ is orders of magnitude larger than would be expected for a cross‐field collisional diffusion process, a result which is identified with the turbulent state of collective beam‐plasma interactions.

show abstract

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Plasma diffusion in a space‐simulation beam‐plasma‐discharge

Szuszczewicz¹,

Walker²,

Holmes³

et al. 1979

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…This plasma physics problem is still under investigation by the 27.010 rocket team. BPD has been reported on rocket flights using similar gun currents and voltages [Galeev et al, 1976;Mishin and Ruzhin, 1978] and in the laboratory under simulated ionospheric conditions [Bernstein et al, 1975[Bernstein et al, , 1979. In a BPD some of the beam energy goes into heating the plasma through the two stream or other instability, but it is not clear just how this would affect the current distribution in space, which determines the radiation efficiency.…”

Section: Discussionmentioning

confidence: 99%

VLF emissions from a modulated electron beam in the auroral ionosphere

Holzworth¹,

Koons²

1981

J. Geophys. Res.

View full text Add to dashboard Cite

A discrete VLF frequency of 3 kHz was successfully radiated by a modulated electron beam on a rocket launched into an active aurora. Instrumentation on this flight included a programable electron accelerator on the aft section with various particle and field detectors on the aft section as well as the ejected forward payload. The accelerator programmer included a current modulation period at fixed electron energy for 0.45‐s duration approximately every 11 s throughout the flight. In each of these program steps, 4‐kV electrons are current modulated at a 3‐kHz rate between Imin=0 or 10 mA and Imax ≅80 mA. The forward payload, which was ejected at about 10 m/s, included a pair of spherical double probes separated by 2.75 m and connected to a VLF receiver operating between 30 Hz and 18 kHz. Both this broadband receiver output as well as various narrow band channel outputs were directly telemetered to ground. Post flight spectrum analysis of the broadband VLF data clearly indicates that signals during the 3‐kHz accelerator modulation periods were propagated to the forward payload. A detailed analysis of these modulated pulses detected by the VLF receiver is presented. A time‐delay analysis between the start of the modulation and detection at the forward payload indicates time delays up to 0.2 s. The electron beam is believed to have produced a beam‐plasma discharge making a radiation efficiency calculation difficult. However, absolute received signal strength was about 1 mV/m at 1.4‐km separation.

show abstract

“…Neither of the above calculations explored systematically two related features which have proven critical to the loss cone instability: the cold electron density and its effects on spatial amplification. A laboratory experiment by Bernstein et al [1975] showed that field-aligned electron beams can also produce multiharmonic instabilities. Such distributions have been observed in space on field lines connecting to the aurora at disturbed times [Mcllwain, 1975;Mauk and Mcllwain, 1978;Parks et al, 1977;Lin et al, 1978].…”

Section: Discussionmentioning

confidence: 99%

A parametric study of electron multiharmonic instabilities in the magnetosphere

Ashour‐Abdalla¹,

Kennel²,

Livesey³

1979

J. Geophys. Res.

View full text Add to dashboard Cite

We present numerical calculations of spatial growth rates of multiharmonic electron cyclotron instabilities driven by a loss cone energetic distribution, in the presence of colder electrons. When the cold electron density is comparable to the hot, nonconvective instability is possible in harmonic bands below or including the cold upper hybrid frequency. When the cold electron density is larger than the hot, nonconvective instability is possible only in that band containing the cold upper hybrid frequency. Increasing the cold electron temperature in relation to the hot eventually removes all nonconvective behavior. Convective instability is still possible above the cold upper hybrid frequency.

show abstract

Laboratory observations of RF emissions at ω_peand (n+ ½)ω_cein Electron beam-plasma and beam-beam interactions

Cited by 55 publications

References 6 publications

Plasma diffusion in a space‐simulation beam‐plasma‐discharge

Plasma diffusion in a space‐simulation beam‐plasma‐discharge

VLF emissions from a modulated electron beam in the auroral ionosphere

A parametric study of electron multiharmonic instabilities in the magnetosphere

Contact Info

Product

Resources

About