@InProceedings{AlvesAlve:2022:ImPiAn,
               author = "Alves, Livia Ribeiro and Alves, M{\'a}rcio E. S.",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade Estadual Paulista (UNESP)}",
                title = "Interaction Time of Relativistic Electrons and Whistler-Mode 
                         Chorus Waves in the Radiation Belt: Implications for the Pitch 
                         Angle Scattering",
                 year = "2022",
         organization = "AGU Fall Meeting",
            publisher = "AGU",
             abstract = "The inner portion of the Earth's magnetic field has a dipolar 
                         configuration. It traps electrons of a broad energy range, from 
                         10's of keV to 10's of MeV, in the outer radiation belt. The 
                         source of the trapped electrons is mainly the solar wind. The 
                         low-energy electrons (10's of keV) are transported throw the 
                         interplanetary media toward the magnetosphere. These particles 
                         reach inside the magnetosphere through magnetic reconnection. 
                         Magnetospheric convection, adiabatic motion, and wave-particle 
                         diffusion transport the electrons from the outskirts of the 
                         magnetosphere to the inner region. Low energy electrons produce 
                         whistler-mode chorus waves, hereafter named chorus waves, due to 
                         plasma temperature anisotropy and the loss cone instability. 
                         Chorus waves are very low frequency (~0.1 - 1 kHz) in 
                         whistler-mode, observed outside the plasmasphere, mainly at the 
                         dawn side magnetosphere. The wave-particle interaction can 
                         accelerate electrons seed population (100's of keV) to MeV 
                         energies. Additionally, the electrons can reach the loss-cone 
                         pitch angles and precipitate into the atmosphere. The 
                         wave-particle interaction succeeds when the resonance condition 
                         between the electron gyrofrequency and the wave frequency is 
                         achieved. The interaction time is a crucial parameter in 
                         estimating wave-particle interaction efficiency. The interaction 
                         occurs in the electron's reference frame, while the measurements 
                         are made in the satellite's frame. Therefore, we perform the 
                         necessary relativistic corrections coming from the frame change. A 
                         test particle approach is used to evaluate the variation of the 
                         electron's pitch angle scattering due to chorus waves propagating 
                         parallel to the ambient magnetic field. We apply wave-particle 
                         resonance conditions for different plasma densities to calculate 
                         the correspondent kinetic energy. Thus, in-situ measurements of 
                         the ambient plasma medium, chorus waves, and electron fluxes are 
                         used to estimate the interaction time. We also evaluate the error 
                         using the non-relativistic formulas for similar estimates. Our 
                         results show that the error in the interaction time scales with 
                         the electron's kinetic energy. The error can be higher than one 
                         order of magnitude for 400 keV low-energy electrons, which 
                         corresponds to the same magnitude error in the change in pitch 
                         angle.",
  conference-location = "Chicago, IL",
      conference-year = "12-16 Dec. 2022",
        urlaccessdate = "07 maio 2024"
}