Electrostatic self-plugging of a picket fence cusped magnetic field

Hershkowitz, N.; Smith, J. R.; Kozima, Hideo

doi:10.1063/1.862450

Cited by 42 publications

(21 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The total potential drop for a 2 eV electron temperature is therefore 10.4 eV, close to the simulation results. The existence of potential maxima along the wall between the cusps, i.e., in the region where the magnetic field is parallel to the surface (regions in red color in Figure 5) is consistent with the electric potential measurements of Hershkowitz et al 6 in the picket fence configuration, and with the particle simulations of Marcus et al 18 .…”

Section: Analysis Of the Simulation Resultssupporting

confidence: 86%

“…In the experiments of Limpaecher and MacKenzie 1 the magnetic cusps were produced by lining the inner wall of the vacuum chamber with permanent magnets 1 while in those of Hershkowitz et al [4][5][6] they were formed by a "picket fence", i.e. an arrangement of parallel water-cooled conductors with current in adjacent conductors flowing in alternate directions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Magnetic cusp confinement in low-β plasmas revisited

et al. 2020

View full text Add to dashboard Cite

Magnetic cusps have been used for more than 50 years to limit charged particle losses to the walls and confine the plasma in a large variety of plasma sources or ion sources. Quantification of the effective loss area has been the subject of many experimental as well as theoretical investigations in the 1970-1990's. In spite of these efforts there is no fully reliable expression of the effective wall loss as a function of cusp magnetic field, electron temperature, ion mass, gas pressure, etc… We describe in this paper a first attempt at obtaining scaling laws for the effective loss width of magnetic cusps, based on two-dimensional PIC MCC (Particle-In-Cell Monte Carlo Collisions) simulations. The results show that the calculated leak width follows a 1/B scaling in the collisionless low B limit, is approximately proportional to the hybrid gyroradius with an ion velocity equal to the Bohm velocity and is proportional to the square root of gas pressure in the collisional limit.

show abstract

Section: Analysis Of the Simulation Resultssupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Magnetic cusp confinement in low-β plasmas revisited

et al. 2020

View full text Add to dashboard Cite

show abstract

“…But the discontinuities in the confining field in the boundary leak the plasma through the cusp regions. The exact scaling for the amount of plasma leaking is not known, though many scaling exists ranging from ion gyro-radius to electron gyro-radius apart from the so-called 'hybrid gyroradius' [10][11][12][13][14]. Also the various fluctuations present in the edge regions (low Beta) and their effect on the central high beta region have not been studied before.…”

Section: Introductionmentioning

confidence: 99%

A new multi-line cusp magnetic field plasma device (MPD) with variable magnetic field

Patel

Sharma

Ramasubramanian

et al. 2018

Review of Scientific Instruments

View full text Add to dashboard Cite

A new multi-line cusp magnetic field plasma device consisting of electromagnets with core material has been constructed with a capability to experimentally control the relative volume fractions of magnetized to unmagnetized plasma volume as well as accurate control on the gradient length scales of mean density and temperature profiles. Argon plasma has been produced using a hot tungsten cathode over a wide range of pressures 5 × 10 -1 × 10 mbar, achieving plasma densities ranging from 10 to 10 cm and the electron temperature in the range 1-8 eV. The radial profiles of plasma parameters measured along the non-cusp region (in between two consecutive magnets) show a finite region with uniform and quiescent plasma, where the magnetic field is very low such that the ions are unmagnetized. Beyond that region, both plasma species are magnetized and the profiles show gradients both in temperature and density. The electrostatic fluctuation measured using a Langmuir probe radially along the non-cusp region shows less than 1% (δI/I < 1%). The plasma thus produced will be used to study new and hitherto unexplored physics parameter space relevant to both laboratory multi-scale plasmas and astrophysical plasmas.

show abstract

“…[1][2][3]5,9 In Table III, comparison of the loss widths obtained by the theory and the experiments in quasineutral plasma is shown. The analytical results obtained here are in good agreement with most experimental results.…”

Section: Discussionmentioning

confidence: 97%

Estimation of the cusp loss width in negative-ion sources

Fukano

Mizuno

Hatayama

et al. 2006

Review of Scientific Instruments

View full text Add to dashboard Cite

To estimate loss width in the cusp magnetic field in multicusp negative-ion sources, diffusion of plasma across magnetic field is investigated analytically. The transport process of plasma depends on various plasma conditions. Diffusion coefficients are classified by degrees of plasma ionization. In weakly ionized plasma, where a case of electron-neutral particle collision is dominant as compared with electron-ion collision, there is a possibility that ambipolar diffusion or electron short circuit occurs in plasma. This strongly depends on the conditions of the plasma, the system length, and the wall material. On the other hand, in fully ionized plasma, only ambipolar diffusion occurs automatically due to momentum conservation of electron and ion. In not fully but strongly ionized plasma, plasma diffusion depends on electron-neutral particle collision, ion-neutral particle collision, and electron-ion collision. Being based on the classification of the diffusion coefficients, we derive expressions of loss widths for various plasma conditions.

show abstract

Electrostatic self-plugging of a picket fence cusped magnetic field

Cited by 42 publications

References 8 publications

Magnetic cusp confinement in low-β plasmas revisited

Magnetic cusp confinement in low-β plasmas revisited

A new multi-line cusp magnetic field plasma device (MPD) with variable magnetic field

Estimation of the cusp loss width in negative-ion sources

Contact Info

Product

Resources

About