Pitch angle distribution of magnetospheric trapped particles: a test-particle simulation

Show simple item record

dc.contributor.author Soni, Pankaj K.
dc.contributor.author Kakad, Bharati
dc.contributor.author Kakad, Amar
dc.date.accessioned 2022-07-27T04:18:54Z
dc.date.available 2022-07-27T04:18:54Z
dc.date.issued 2021
dc.identifier.citation Advances in Space Research, https://doi.org/10.1016/j.asr.2021.06.004 en_US
dc.identifier.uri http://library.iigm.res.in:8080/xmlui/handle/123456798/203
dc.description.abstract This article aims to understand the pitch angle distributions (PADs) of the charged particles in the Earth’s inner magnetosphere using test-particle simulations. The emphasis is on characterizing the variation in pitch angle of the charged particles trapped along the Earth’s magnetic field lines. These charged particles undergo gyration, bounce, and azimuthal drift motions in the Earth’s inner magnetosphere. They are trapped until their pitch angle falls into the loss-cone to get lost into the upper atmosphere. We have developed a three-dimensional test-particle simulation model in which the relativistic equation of motion is solved numerically to track these trapped particle’s trajectories. We have examined the pitch angle distributions of the electron, proton, and oxygen for the cases where adiabatic invariants are conserved and non-conserved. For this purpose, we have considered the particle’s trajectory in the latitudinal range of [ 40 ; 40 ] for one complete drift around the Earth. We found that when adiabatic invariants are conserved, the particles possess butterfly-type pitch angle distributions. Whereas, when adiabatic invariants are not conserved, the particle’s pitch angle distribution bunches toward the 90 -peaked distribution. The situation of non-conservation of adiabatic invariants demonstrated in the present simulation is arising due to larger gyro-radius (few Earth radii) over which the ambient magnetic field is not constant. We have noticed that in the static dipolar magnetic field, all three, 1st, 2nd, and partly 3rd adiabatic invariants are non-conserved when gyro-radius is larger. The information on the change in the pitch angle distribution pattern from butterfly-type to 90 -peak distribution will be useful to understand the pitch angle distributions observed by the recent spacecraft in the Earth’s radiation belts. en_US
dc.language.iso en en_US
dc.subject Test particle simulation, Trapped particle trajectories, Pitch angle distributions, Magnetospheric plasma, Earth’s inner magnetosphere en_US
dc.title Pitch angle distribution of magnetospheric trapped particles: a test-particle simulation en_US
dc.type Article en_US


Files in this item

This item appears in the following Collection(s)

Show simple item record

Search DSpace


Advanced Search

Browse

My Account