skip to main content

DOE PAGESDOE PAGES

Title: PIC simulations of wave-particle interactions with an initial electron velocity distribution from a kinetic ring current model

Whistler wave-particle interactions play an important role in the Earth inner magnetospheric dynamics and have been the subject of numerous investigations. By running a global kinetic ring current model (RAM-SCB) in a storm event occurred on Oct 23–24 2002, we obtain the ring current electron distribution at a selected location at MLT of 9 and L of 6 where the electron distribution is composed of a warm population in the form of a partial ring in the velocity space (with energy around 15 keV) in addition to a cool population with a Maxwellian-like distribution. The warm population is likely from the injected plasma sheet electrons during substorm injections that supply fresh source to the inner magnetosphere. These electron distributions are then used as input in an implicit particle-in-cell code (iPIC3D) to study whistler-wave generation and the subsequent wave-particle interactions. Here, we find that whistler waves are excited and propagate in the quasi-parallel direction along the background magnetic field. Several different wave modes are instantaneously generated with different growth rates and frequencies. The wave mode at the maximum growth rate has a frequency around 0.62ω ce, which corresponds to a parallel resonant energy of 2.5 keV. Linear theory analysis of wavemore » growth is in excellent agreement with the simulation results. These waves grow initially due to the injected warm electrons and are later damped due to cyclotron absorption by electrons whose energy is close to the resonant energy and can effectively attenuate waves. The warm electron population overall experiences net energy loss and anisotropy drop while moving along the diffusion surfaces towards regions of lower phase space density, while the cool electron population undergoes heating when the waves grow, suggesting the cross-population interactions.« less
Authors:
 [1] ; ORCiD logo [2] ; ORCiD logo [2] ;  [3] ;  [3]
  1. Beihang Univ., Beijing (China). School of Space and Environment
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. KTH Royal Inst. of Technology, Stockholm (Sweden)
Publication Date:
Report Number(s):
LA-UR-17-22219
Journal ID: ISSN 1364-6826
Grant/Contract Number:
AC52-06NA25396; 41574156; D621-2013-4309
Type:
Accepted Manuscript
Journal Name:
Journal of Atmospheric and Solar-Terrestrial Physics
Additional Journal Information:
Journal Name: Journal of Atmospheric and Solar-Terrestrial Physics; Journal ID: ISSN 1364-6826
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Heliospheric and Magnetospheric Physics; Wave-particle interactions; Realistic non-Maxwellian electron distribution; Whistler wave generation
OSTI Identifier:
1392808