Suprathermal electrons observed on the TSS‐1R satellite

Winningham, J. D.; Stone, N. H.; Gurgiolo, C.; Wright, K. H.; Frahm, R. A.; Bonifazi, C.

doi:10.1029/97gl03187

Cited by 11 publications

(9 citation statements)

References 4 publications

(2 reference statements)

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“…Specifically, the TSS-1R results found that as the satellite potential exceeded the ram kinetic energy of O ions (5.3 eV), the level of kilohertz wave activity increased dramatically [26] and a suprathermal electron population appeared at the satellite's surface [27]. The distributions of wave activity and suprathermal electron fluxes were quite nonuniform around the satellite, indicative of both ram and magnetic field limitations to the current collection.…”

Section: B Current Collection Datamentioning

confidence: 96%

Analysis of chamber simulations of long collecting probes in high-speed dense plasmas

Gilchrist

Bilén

Choinière

et al. 2002

IEEE Trans. Plasma Sci.

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Chamber tests of simulated electrodynamic tethers (EDTs) of different geometries operating in a dense high-speed plasma are described. The geometries tested and described here are cylindrical and flat-ribbon tape. By moving the probe samples relative to the plasma source it was possible to vary the density and therefore the effective width over a range of approximately 1 to 2 Debye lengths ( ) for the cylinder sample and 6 to 19 for the tape samples. Several important conclusions can be drawn from the tests. 1) The current-voltage characteristics of the cylinder behave as predicted by orbital-motion-limited (OML) current collection theory in the saturation region. 2) The tape tether had comparable current levels to a theoretical equal area OML cylinder up to an effective width of at least 11 and possibly wider. 3) Orienting the tape samples parallel or perpendicular to the plasma flow yielded different current responses (perpendicular is larger) above a bias potential that is near the estimated energy of the incoming beam ions. The observed difference was generally more pronounced at larger effective widths (higher densities). 4) It was also necessary to be above this bias potential to have a 0 5 current-voltage character appropriate for an ideal cylinder in the OML regime. It is concluded that wide ribbon-like tape tethers can be effective current collectors but that velocity effects will be a factor to consider, especially as relative width of the tape tether (with respect to ) grows.

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Section: B Current Collection Datamentioning

confidence: 96%

Analysis of chamber simulations of long collecting probes in high-speed dense plasmas

Gilchrist

Bilén

Choinière

et al. 2002

IEEE Trans. Plasma Sci.

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“…Figure 13 for the space charge atr = 0 (wherer −1 (∂/∂r)r ∂φ/∂r does not vanish) shows the double layer structure peaking before decreasing along the magnetic field. Independently, note that contrary to the case of equation (25), all terms in equation (4 ) and (the left-hand side of) equation (6 ) are comparable. That means that describing transport in our magnetized plasma as a onedimensional problem because cross-field diffusion is much weaker than parallel diffusion is an often used approximation not more valid than in the case of no magnetic field.…”

Section: Figures 1 Andmentioning

confidence: 84%

“…In cold but rarefied, unbounded collisionless space plasmas, probes may be biased highly positive [3], with recent theoretical developments for new applications [4,5]. Ionospheric experiments have found particles heated in the plasma beyond probe [6,7] or spacecraft [8] sheaths.…”

Section: Introductionmentioning

confidence: 99%

New books on physics and related sciences

Zakharova¹

2002

Phys.-Usp.

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The electron-retarding range of the current-voltage characteristic of a flat Langmuir probe perpendicular to a strong magnetic field in a fully ionized plasma is analysed allowing for anomalous (Bohm) cross-field transport and temperature changes in the collection process. With probe size and ion thermal gyroradius comparable, and smaller than the electron mean free path, there is an outer quasineutral region with ion viscosity determinant in allowing nonambipolar parallel and cross flow. A potential overshoot lying either at the base or inside the quasineutral region both makes ions follow Boltzmann's law at negative bias and extends the electron-retarding range to probe bias eφ P ∼ +2T ∞ . Electron heating and cooling occur roughly at positive and negative bias, with a T e -minimum around eφ P ∼ −2T ∞ ; far from the probe heat conduction cools and heats electrons at and radially away from the probe axis, respectively. The potential overshoot with no thermal effects would reduce the electron current I e , making the ln I e versus φ P graph downwards-concave, but cooling further reduces I e substantially, and may tilt the slope upwards past the temperature minimum. The domain of strict validity of our analysis is narrow in case of low ion mass (deuterium), breaking down with the ion Boltzmann law.

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“…Particle measurements up to 27 keV were performed on the TSS-1R to track the spacecraft potential and collected current. In addition to the accelerated ionospheric electrons (∼ 70 eV), a suprathermal population of electrons was observed to be centered around 200 eV (Winningham et al, 1998). The authors assumed an AC acceleration of the suprathermal electrons whose free energy is gained from the differential (E × B driven) drift between electrons and ions.…”

Section: Active Experimentsmentioning

confidence: 99%

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

et al. 2002

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Abstract. The APEX project (Active Plasma Experiment) has been launched into a polar orbit in December 1991 and consists of two satellites (IK-25 and MAGION-3), with a distance between them from 200 km to 10 000 km. The mission used intensive electron beam emission, complemented by a low-energy Xenon plasma generator during the electron beam injection, for the study of dynamic processes in the magnetosphere and upper ionosphere.The paper deals with short, intensive bursts of fieldaligned electrons observed during the APEX mission on board the MAGION-3 satellite. These events are located predominantly at the middle geomagnetic latitudes in the dayside magnetosphere. The time-energy structure of these electron bursts is similar to the inverted-V one, but the pitchangle width is less than 10 • . Electrons with an energy up to 700 keV are often observed during the events. We analyze the observed events, discuss the possible mechanisms of the particle spreading, and the role of the main satellite's activity as a possible source of these events.

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Suprathermal electrons observed on the TSS‐1R satellite

Cited by 11 publications

References 4 publications

Analysis of chamber simulations of long collecting probes in high-speed dense plasmas

Analysis of chamber simulations of long collecting probes in high-speed dense plasmas

New books on physics and related sciences

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

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