Actively produced high-energy electron bursts within the magnetosphere: the APEX project

Přech, Lubomír; Němeček, Zdenek; Šafránková, Jana; Omar, Amitesh

doi:10.5194/angeo-20-1529-2002

Cited by 11 publications

(12 citation statements)

References 33 publications

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“…Electron beams from spacecraft have been propagated long distances through regions of the magnetosphere [Hendrickson et al, 1975;Hallinan et al, 1978;Winckler, 1980;Pellat and Sagdeev, 1980;Zhulin et al, 1980;Nemzek and Winckler, 1991;Lavergnat, 1982;Prech et al, 2002], but all of these beams were launched from spacecraft that were in the ionosphere, where the plasma is sufficiently dense to provide the return current needed to avoid the spacecraft charging to levels that prevent further beam emission. SCATHA (also known as P78-2), on the other hand, was a rather unique experiment involving electron beams in the magnetosphere (at the geosynchronous orbit).…”

Section: Introductionmentioning

confidence: 99%

Future beam experiments in the magnetosphere with plasma contactors: How do we get the charge off the spacecraft?

et al. 2015

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Key Points:• The contactor plasma mitigates spacecraft charging from electron beam emission • The contactor allows ion emission over a larger, quasi-spherical area • The peak of the spacecraft potential is lower for larger contactor clouds AbstractThe idea of using a high-voltage electron beam with substantial current to actively probe magnetic field line connectivity in space has been discussed since the 1970s. However, its experimental realization onboard a magnetospheric spacecraft has never been accomplished because the tenuous magnetospheric plasma cannot provide the return current necessary to keep spacecraft charging under control. In this work, we perform Particle-In-Cell simulations to investigate the conditions under which a high-voltage electron beam can be emitted from a spacecraft and explore solutions that can mitigate spacecraft charging. The electron beam cannot simply be compensated for by an ion beam of equal current, because the Child-Langmuir space charge limit is violated under conditions of interest. On the other hand, releasing a high-density neutral contactor plasma prior and during beam emission is critical in aiding beam emission. We show that after an initial transient controlled by the size of the contactor cloud where the spacecraft potential rises, the spacecraft potential can settle into conditions that allow for electron beam emission. A physical explanation of this result in terms of ion emission into spherical geometry from the surface of the plasma cloud is presented, together with scaling laws of the peak spacecraft potential varying the ion mass and beam current. These results suggest that a strategy where the contactor plasma and the electron beam operate simultaneously might offer a pathway to perform beam experiments in the magnetosphere.

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Section: Introductionmentioning

confidence: 99%

Future beam experiments in the magnetosphere with plasma contactors: How do we get the charge off the spacecraft?

et al. 2015

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“…Electron beam experiments have been successfully operated many times from rockets and spacecraft in the ionosphere, where the ambient plasma is dense [Hendrickson et al, 1975;Hallinan et al, 1978;Winckler, 1980;Pellat and Sagdeev, 1980;Zhulin et al, 1980;Swanson et al, 1986;Nemzek and Winckler, 1991;Nemzek et al, 1992;Lavergnat, 1982;Prech et al, 1995Prech et al, , 2002Katz et al, 1994]. In the ionosphere a sufficient return current can be drawn from the background plasma to balance the electron beam current and to maintain spacecraft charging to low levels that do not prevent beam emission.…”

Section: Introductionmentioning

confidence: 99%

Future beam experiments in the magnetosphere with plasma contactors: The electron collection and ion emission routes

et al. 2015

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Experiments where a high-voltage electron beam emitted by a spacecraft in the low-density magnetosphere is used to probe the magnetospheric configuration could greatly enhance our understanding of the near-Earth environment. Their challenge, however, resides in the fact that the background magnetospheric plasma cannot provide a return current that balances the electron beam current without charging the spacecraft to such high potential that in practice prevents beam emission. In order to overcome this problem, a possible solution is based on the emission of a high-density contactor plasma by the spacecraft prior to and after the beam. We perform particle-in-cell simulations to investigate the conditions under which a high-voltage electron beam can be emitted from a magnetospheric spacecraft, comparing two possible routes that rely on the high-density contactor plasma. The first is an "electron collection" route, where the contactor has lower current than the electron beam and is used with the goal of connecting to the background plasma and collecting magnetospheric electrons over a much larger area than that allowed by the spacecraft alone. The second is an "ion emission" route, where the contactor has higher current than the electron beam. Ion emission is then enabled over the large quasi-spherical area of the contactor cloud, thus overcoming the space charge limits typical of ion beam emission. Our results indicate that the ion emission route offers a pathway for performing beam experiments in the low-density magnetosphere, while the electron collection route is not viable because the contactor fails to draw a large neutralizing current from the background.

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“…The burst cross section was spatially limited to several tens of kilometers in the direction of the orbit and the electron energy extended to several hundred keV, without measurable dispersion indicating proximity of the source. The events had different characteristics than electron microbursts already reported in the literature (for a short review see Prech et al, 2002). Examples of bursts registered by MAGION-3 are presented in Figure 11.…”

Section: Distant Injection Effectsmentioning

confidence: 90%

“…The energetic particle sensor DOK-A-S registered energetic electron and proton fluxes parallel and perpendicular to the satellite axis using two pairs of silicon detectors (Prech et al, 2002;Baranets et al, 2007).…”

Section: Magion-3 Short Descriptionmentioning

confidence: 99%

“…3.4.1. Energetic Particles Nemecek et al (1996) and Prech et al (2002) reported on observations of short intensive bursts of narrow-beam electrons onboard MAGION-3 during the electron injections from the main IK-25 satellite. The events were registered in the middle geomagnetic latitudes (INL < 55 • ) near local noon when the two satellites moved approximately along the same magnetic meridian at relative distances 64-550 km.…”

Section: Distant Injection Effectsmentioning

confidence: 99%

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Overview of APEX Project Results

Přech

Ruzhin

Dokukin

et al. 2018

Front. Astron. Space Sci.

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Actively produced high-energy electron bursts within the magnetosphere: the APEX project

Cited by 11 publications

References 33 publications

Future beam experiments in the magnetosphere with plasma contactors: How do we get the charge off the spacecraft?

Future beam experiments in the magnetosphere with plasma contactors: How do we get the charge off the spacecraft?

Future beam experiments in the magnetosphere with plasma contactors: The electron collection and ion emission routes

Overview of APEX Project Results

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