A Review of Reflex and Penning Discharges

Hooper, E. B.

doi:10.1016/s0065-2539(08)60040-2

Cited by 43 publications

(19 citation statements)

References 106 publications

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“…We briefly summarize here the principles and properties of these crossed-field discharges. More details and references can be found in the early review of low pressure magnetically confined discharges by Hooper [1], in the paper on instabilities in low pressure crossed-field devices by Redhead [2] and in the more recent reviews on E × B devices by Keidar and Billis [3], and Abolmasov [4]. Depending on pressure, magnetic field, and applied voltage, different regimes of the discharges in the E × B configurations of Figure 1 can be observed and Abolmassov [4] proposed a classification of these regimes based on the categories defined by Schuurman [5] for Penning discharges.…”

Section: E × B Plasma Devicesmentioning

confidence: 99%

Rotating structures in low temperature magnetized plasmasâ€”insight from particle simulations

Boeuf

2014

Front. Phys.

100

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The E × B configuration of various low temperature plasma devices is often responsible for the formation of rotating structures and instabilities leading to anomalous electron transport across the magnetic field. In these devices, electrons are strongly magnetized while ions are weakly or not magnetized and this leads to specific physical phenomena that are not present in fusion plasmas where both electrons and ions are strongly magnetized. In this paper we describe basic phenomena involving rotating plasma structures in simple configurations of low temperature E × B plasma devices on the basis of PIC-MCC (Particle-In-Cell Monte Carlo Collisions) simulations. We focus on three examples: rotating electron vortices and rotating spokes in cylindrical magnetrons, and azimuthal electron-cyclotron drift instability in Hall thrusters. The simulations are not intended to give definite answers to the many physics issues related to low temperature E × B plasma devices but are used to illustrate and discuss some of the basic questions that need further studies.

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Section: E × B Plasma Devicesmentioning

confidence: 99%

Rotating structures in low temperature magnetized plasmasâ€”insight from particle simulations

Boeuf

2014

Front. Phys.

100

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“…In partially magnetized discharges such as Hall thrusters 1,2 , magnetron discharges 3 , ion sources for neutral beam injection 4 , Penning discharges 5 , etc…, the region of strong ionization is separated from the anode by a region of relatively low magnetic field and low electron temperature that we call "near-anode region" in this paper. In a Hall thruster, the length of this region in on the order of 1 to 2 cm, the gas pressure is in the mtorr range and the average magnetic field is on the order of or less than 50 G. Electrons are magnetized and collisional but the Hall parameter (ratio of the electron cyclotron frequency to the electron collision frequency) is large and their residence time is considerably increased by the magnetic field in the absence of instabilities.…”

Section: Introductionmentioning

confidence: 99%

Micro instabilities and rotating spokes in the near-anode region of partially magnetized plasmas

Boeuf

2019

Physics of Plasmas

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Electron and ion transport in the near-anode region of a partially magnetized plasma under conditions typical of Hall thrusters or magnetron discharges is studied with fully kinetic, Particle-In-Cell Monte Carlo Collision (PIC-MCC) simulations assuming a uniform magnetic field and no ionization. We derive a simple relation that defines the magnetic field at the transition point between negative and positive sheath. For magnetic fields around or above this transition point, PIC-MCC simulations show the development of short wavelength azimuthal instabilities that cascade to longer wavelengths ("rotating spokes") as the magnetic field is increased. Both short-wavelength and large-wavelength fluctuations can coexist under some conditions. A detailed study of the fluid dispersion relation is used to analyze the PIC-MCC results. Small coherent structures can be associated with the destabilization of ion sound waves by density gradient and collisions. Longer wavelengths or rotating spokes are characteristic of the collisionless Simon-Hoh instability. The small structures are dominant for larger plasma density gradients while the larger structures correspond to smaller density gradients and larger magnetic fields. Anomalous transport associated with these instabilities can be significant, with effective collision frequencies larger than 2 × 10 7 s −1 in xenon for magnetic fields above the transition point.

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“…The acquisition of such data is the focus of ongoing work, which also includes an investigation of the plasma fluctuation characteristics, motivated by the prevalence of substantial low frequency oscillations in similar plasma devices. [17][18][19] …”

Section: Discussionmentioning

confidence: 99%

The Plasma-Material Interactions Facility at UCLA

Matlock

Conversano

Goebel

et al. 2013

49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

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A new device has been constructed for the investigation of interactions between engineered materials and a plasma in the regime relevant to electric propulsion. The facility is comprised of a cylindrical vacuum chamber with a flange-mounted, hollow cathode plasma source running perpendicular to the chamber axis. The plasma source delivers unmagnetized ions and thermal, magnetized electrons to a cooled target mounted on the opposing flange. The ion energy impacting the surface is controlled by the sample bias relative to the plasma potential, which is maintained near the chamber potential. This paper discusses the major aspects of the plasma source design and presents preliminary measurements of the plasma parameters achieved to date.

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A Review of Reflex and Penning Discharges

Cited by 43 publications

References 106 publications

Rotating structures in low temperature magnetized plasmasâ€”insight from particle simulations

Rotating structures in low temperature magnetized plasmasâ€”insight from particle simulations

Micro instabilities and rotating spokes in the near-anode region of partially magnetized plasmas

The Plasma-Material Interactions Facility at UCLA

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