Magnetopause characteristics inferred from three-dimensional energetic particle distributions

1979 ◽  
Vol 84 (A1) ◽  
pp. 101-104 ◽  
Author(s):  
D. J. Williams
Keyword(s):  
Energetic Particle ◽  
Three Dimensional ◽  
Particle Distributions

scholarly journals Energetic particle observations at the subsolar magnetopause

2002 ◽  
Vol 20 (4) ◽  
pp. 445-460 ◽  
Author(s):  
A. A. Eccles ◽  
T. A. Fritz
Keyword(s):  
Pitch Angle ◽  
Energetic Particle ◽  
Three Dimensional ◽  
Extended Period ◽  
Energetic Particles ◽  
Current Layer ◽  
Particle Distributions ◽  
Magnetospheric Configuration And Dynamics ◽  
Subsolar Point ◽  
Magnetospheric Configuration

Abstract. The pitch-angle distributions (PAD) of energetic particles are examined as the ISEE-1 satellite crosses the Earth’s magnetopause near the subsolar point. The investigation focuses on the possible existence of a particular type of distribution that would be associated with a source of energetic particles in the high-latitude magnetosphere. PADs, demonstrating broad, persistent field-aligned fluxes filling a single hemisphere (upper/northern or lower/southern), were observed just sunward of the magnetopause current layer for an extended period of many minutes. These distributions are a direct prediction of a possible source of energetic particles located in the high altitude dayside cusp and we present five examples in detail of the three-dimensional particle distributions to demonstrate their existence. From these results, other possible causes of such PADs are examined.Key words. Magnetospheric physics (energetic particles, precipitating; magnetopause, cusp and boundary layers; magnetospheric configuration and dynamics)

Solving the 3D structure of metal nanoparticles

2007 ◽  
Vol 222 (11/2007) ◽  
Author(s):  
Anatoly Frenkel
Keyword(s):  
Metal Nanoparticles ◽  
Short Range ◽  
Short Range Order ◽  
3D Structure ◽  
Three Dimensional ◽  
X Ray ◽  
Particle Distributions ◽  
Structure Of Metal ◽  
X Ray Absorption

We discuss methods of Extended X-ray Absorption Fine-Structure (EXAFS) analysis that provide three-dimensional structural characterization of metal nanoparticles, both mono- and bi-metallic. For the bimetallic alloys, we use short range order measurements to discriminate between random and non-random inter-particle distributions of atoms. We also discuss the application of EXAFS to heterogeneous nanoparticle systems.

The Deflection Magnet Design for PKU Energetic Particle Instrument

2020 ◽  
Author(s):  
Weihong Shi ◽  
Xiangqian Yu ◽  
Yongfu Wang ◽  
Linghua Wang ◽  
Xin Huang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energetic Particle ◽  
Permanent Magnets ◽  
Interplanetary Space ◽  
Three Dimensional ◽  
Good Time ◽  
Electrons And Ions ◽  
Peking University ◽  
Dimensional Distribution ◽  
The Magnetic Field

<p>The Energetic Particle Instrument (EPI), proposed by Peking University for a L1 mission, is designed to provide the three-dimensional distribution of suprathermal electrons and ions with good time, energy and angular resolutions in the interplanetary space, respectively, at energies from 20 keV to 1 MeV and from 20 keV to 11 MeV.  The EPI consists of four dual-double-ended foil/magnet semi-conductor telescopes, which cleanly separate electrons in the energy range from 20 to 400 keV and ions from 20 keV to 6 MeV.</p><p>The magnet of semi-conductor telescopes consists of four type 677H rare earth permanent magnets and a soft iron frame. Due to the high saturation polarization and high magnetic anisotropy of the Nd<sub>2</sub>Fe<sub>14</sub>B strongly magnetic matrix phase, this system can make the magnetic field strong enough to make the electrons deflected.</p><p>A frame made of iron-cobalt alloy VACOFLUX 50 will be able to combine two pairs of magnets and cause the magnetic field to decay rapidly in the far field. In this way, the two air gaps in the system can simultaneously provide a deflecting magnetic field for a pair of anti-parallel sensor systems.</p>

PKU Energetic Particle Instrument

2020 ◽  
Author(s):  
Liu Yang ◽  
Linghua Wang ◽  
Qiugang Zong ◽  
Xiangqian Yu ◽  
Yongfu Wang ◽  
...  
Keyword(s):  
Energy Range ◽  
Energetic Particle ◽  
Interplanetary Space ◽  
Nuclear Charge ◽  
Three Dimensional ◽  
Good Time ◽  
Suprathermal Electrons ◽  
Electrons And Ions ◽  
Dimensional Distribution ◽  
Ion Species

<p>The PKU energetic particle instrument (EPI) is designed to make measurements of the three-dimensional distribution of suprathermal electrons and ions with good time, energy and angular resolutions in the interplanetary space, respectively, at energies from 20 keV to 1 MeV and from 20 keV to 11 MeV.  The EPI consists of four dual-double-ended foil/magnet semi-conductor telescopes, which cleanly separate electrons in the energy range of 20–400 keV and ions from 20 keV–6 MeV. The output of front detectors is taken in anti-coincidence with center detectors, to achieve the low background. The magnet telescopes also employ the well-established dE/dx vs. total energy approach to determine the nuclear charge and mass of some ion species.</p>

Three dimensional Fokker-Planck calculation of alpha particle distributions: a TFTR simulation

1995 ◽  
Vol 35 (12) ◽  
pp. 1537-1541 ◽  
Author(s):  
M.R O`Brien ◽  
M Cox ◽  
C.A Gardner ◽  
F.S Zajtsev
Keyword(s):  
Alpha Particle ◽  
Three Dimensional ◽  
Particle Distributions ◽  
Fokker Planck

scholarly journals Properties of fast solitary structures

1999 ◽  
Vol 6 (3/4) ◽  
pp. 187-194 ◽  
Author(s):  
R. E. Ergun ◽  
C. W. Carlson ◽  
L. Muschietti ◽  
I. Roth ◽  
J. P. McFadden
Keyword(s):  
Electromagnetic Waves ◽  
Electron Beams ◽  
Three Dimensional ◽  
Auroral Zone ◽  
Analytical Treatment ◽  
Particle Distributions ◽  
Solitary Structures ◽  
The One ◽  
The Magnetic Field ◽  
Coherent Plasma

Abstract. We present detailed observations of electromagnetic waves and particle distributions from the Fast Auroral SnapshoT (FAST) satellite which reveal many important properties of large-amplitude, spatially-coherent plasma structures known as "fast solitary structures" or "electron phase space holes". Similar structures have been observed in several regions of the magnetosphere including the auroral zone, plasma sheet boundary layer, and bow shock. There has been rapid theoretical progress in understanding these structures. Solitary structures can develop from bidirectional electron beams. Once developed, the one-dimensional properties parallel to the magnetic field can be adequately described by analytical treatment as BGK structures. There remains, however, several unanswered questions. The origin of the bidirectional electron beams, the development of two-or three-dimensional structures, and the observed association with the ion cyclotron frequency are not well understood.

scholarly journals Jets of energetic particles generated by magnetic reconnection at a three-dimensional magnetic null

2006 ◽  
Vol 2 (14) ◽  
pp. 98-98
Author(s):  
Silvia Dalla ◽  
Philippa K. Browning
Keyword(s):  
Particle Acceleration ◽  
Magnetic Reconnection ◽  
Energetic Particle ◽  
Three Dimensional ◽  
Null Point ◽  
Numerical Code ◽  
Coronal Magnetic Fields ◽  
Field Lines ◽  
Magnetic Null ◽  
Magnetic Null Point

AbstractMagnetic reconnection is a candidate mechanism for particle acceleration in a variety of astrophysical contexts. It is now widely accepted that reconnection plays a key role in solar flares, and reconstructions of coronal magnetic fields indicate that three-dimensional (3D) magnetic null points can be present during flares. We investigate particle acceleration during spine reconnection at a 3D magnetic null point, using a test particle numerical code. We observe efficient particle acceleration and find that two energetic populations are produced: a trapped population of particles that remain in the vicinity of the null, and an escaping population, which leave the configuration in two symmetric jets along field lines near the spine. While the parameters used in our simulation aim to represent solar coronal plasma conditions of relevance for acceleration in flares, the fact that the 3D spine reconnection configuration naturally results in energetic particle jets may be of importance in other astrophysical situations. We also compare the results obtained for the spine reconnection regime with those for the other possible mode of 3D reconnection, fan reconnection. We find that in the latter case energetic particle jets are not produced, though acceleration is observed.

scholarly journals Advancing the physics basis for quasi-helically symmetric stellarators

2020 ◽  
Vol 86 (5) ◽  
Author(s):  
A. Bader ◽  
B. J. Faber ◽  
J. C. Schmitt ◽  
D. T. Anderson ◽  
M. Drevlak ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Turbulent Transport ◽  
Three Dimensional ◽  
Plasma Pressure ◽  
Ion Temperature ◽  
Single Filament ◽  
Ion Temperature Gradient ◽  
Vessel Volume ◽  
Energetic Particle Transport ◽  
Particle Confinement

A new optimized quasi-helically symmetric configuration is described that has the desirable properties of improved energetic particle confinement, reduced turbulent transport by three-dimensional shaping and non-resonant divertor capabilities. The configuration presented in this paper is explicitly optimized for quasi-helical symmetry, energetic particle confinement, neoclassical confinement and stability near the axis. Post optimization, the configuration was evaluated for its performance with regard to energetic particle transport, ideal magnetohydrodynamic stability at various values of plasma pressure and ion temperature gradient instability induced turbulent transport. The effects of discrete coils on various confinement figures of merit, including energetic particle confinement, are determined by generating single-filament coils for the configuration. Preliminary divertor analysis shows that coils can be created that do not interfere with expansion of the vessel volume near the regions of outgoing heat flux, thus demonstrating the possibility of operating a non-resonant divertor.

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