Pickup proton cyclotron turbulence at comet P/Halley

1995 ◽  
Vol 100 (A3) ◽  
pp. 3449-3454 ◽  
Author(s):  
G. S. Lakhina ◽  
Frank Verheest
Keyword(s):  
Pickup Proton ◽  
Proton Cyclotron

Development of a New Radiobiology Beam Line for the Study of Proton RBE at the 18 MeV Proton Cyclotron Facility at CNA

2019 ◽  
pp. 175-176
Author(s):  
A. Baratto-Roldán ◽  
M. A. Cortés-Giraldo ◽  
M. C. Jiménez-Ramos ◽  
M. C. Battaglia ◽  
J. García López ◽  
...  
Keyword(s):  
Beam Line ◽  
Proton Cyclotron

Erratum: “Electromagnetic Waves near the Proton Cyclotron Frequency: STEREO Observations” (2014, ApJ, 786, 123)

2017 ◽  
Vol 847 (1) ◽  
pp. 82
Author(s):  
L. K. Jian ◽  
H. Y. Wei ◽  
C. T. Russell ◽  
J. G. Luhmann ◽  
B. Klecker ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Cyclotron Frequency ◽  
Proton Cyclotron

scholarly journals Nonlinear Alfvén waves, discontinuities, proton perpendicular acceleration, and magnetic holes/decreases in interplanetary space and the magnetosphere: intermediate shocks?

2005 ◽  
Vol 12 (3) ◽  
pp. 321-336 ◽  
Author(s):  
B. T. Tsurutani ◽  
G. S. Lakhina ◽  
J. S. Pickett ◽  
F. L. Guarnieri ◽  
N. Lin ◽  
...  
Keyword(s):  
Interplanetary Space ◽  
Alfven Waves ◽  
Alfven Wave ◽  
Alfvén Waves ◽  
Reverse Shock ◽  
Propagating Waves ◽  
Mirror Mode ◽  
Interaction Regions ◽  
Electron Holes ◽  
Proton Cyclotron

Abstract. Alfvén waves, discontinuities, proton perpendicular acceleration and magnetic decreases (MDs) in interplanetary space are shown to be interrelated. Discontinuities are the phase-steepened edges of Alfvén waves. Magnetic decreases are caused by a diamagnetic effect from perpendicularly accelerated (to the magnetic field) protons. The ion acceleration is associated with the dissipation of phase-steepened Alfvén waves, presumably through the Ponderomotive Force. Proton perpendicular heating, through instabilities, lead to the generation of both proton cyclotron waves and mirror mode structures. Electromagnetic and electrostatic electron waves are detected as well. The Alfvén waves are thus found to be both dispersive and dissipative, conditions indicting that they may be intermediate shocks. The resultant "turbulence" created by the Alfvén wave dissipation is quite complex. There are both propagating (waves) and nonpropagating (mirror mode structures and MDs) byproducts. Arguments are presented to indicate that similar processes associated with Alfvén waves are occurring in the magnetosphere. In the magnetosphere, the "turbulence" is even further complicated by the damping of obliquely propagating proton cyclotron waves and the formation of electron holes, a form of solitary waves. Interplanetary Alfvén waves are shown to rapidly phase-steepen at a distance of 1AU from the Sun. A steepening rate of ~35 times per wavelength is indicated by Cluster-ACE measurements. Interplanetary (reverse) shock compression of Alfvén waves is noted to cause the rapid formation of MDs on the sunward side of corotating interaction regions (CIRs). Although much has been learned about the Alfvén wave phase-steepening processfrom space plasma observations, many facets are still not understood. Several of these topics are discussed for the interested researcher. Computer simulations and theoretical developments will be particularly useful in making further progress in this exciting new area.

Subgrid modelling of ion pitch-angle scattering for magnetosheath waves in a global hybrid-Vlasov simulation

2021 ◽  
Author(s):  
Maxime Dubart ◽  
Urs Ganse ◽  
Adnane Osmane ◽  
Andreas Johlander ◽  
Markus Battarbee ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Numerical Simulations ◽  
Spatial Resolution ◽  
Pitch Angle ◽  
Space Physics ◽  
Distribution Functions ◽  
Cyclotron Instability ◽  
Angle Scattering ◽  
Velocity Distribution Functions ◽  
Proton Cyclotron

<p>Numerical simulations are widely used in modern space physics and are an essential tool to understand or discover new phenomena which cannot be observed using spacecraft measurements. However, numerical simulations are limited by the space grid resolution of the system and the computational costs of having a high spatial resolution. Therefore, some physics may be unresolved in part of the system due to its low spatial resolution. We have previously identified, using Vlasiator, that the proton cyclotron instability is not resolved for grid cell sizes larger than four times the inertial length in the solar wind, for waves in the downstream of the quasi-perpendicular shock in the magnetosheath of a global hybrid-Vlasov simulation. This leads to unphysically high perpendicular temperature and a dominance of the mirror mode waves. In this study, we use high-resolution simulations to measure and quantify how the proton cyclotron instability diffuses and isotropizes the velocity distribution functions. We investigate the process of pitch-angle scattering during the development of the instability and propose a method for the sub-grid modelling of the diffusion process of the instability at low resolution. This allows us to model the isotropization of the velocity distribution functions and to reduce the temperature anisotropy in the plasma while saving computational resources.</p>

scholarly journals Commissioning of RF system of the 200 MeV proton cyclotron

2019 ◽  
Vol 1350 ◽  
pp. 012191
Author(s):  
Gen Chen ◽  
Guang Liu ◽  
Yanping Zhao ◽  
Zhen Peng ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Rf System ◽  
Proton Cyclotron
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