Upload
airell
View
63
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Particle Tracking in Mercury’s Magnetosphere. Albert Ryou Brian Walsh. Missions to Mercury. Mariner 10, 1974-5. MESSENGER, 2008-present. BepiColombo , 2018. Objective: What can we learn about the electrons around Mercury from kinetic particle modeling?. 1. Magnetosphere 2. Particle motion - PowerPoint PPT Presentation
Citation preview
Particle Tracking in Mercury’s Magnetosphere
Albert RyouBrian Walsh
Mariner 10, 1974-5
Missions to Mercury
MESSENGER, 2008-present
BepiColombo, 2018
Objective: What can we learn about the electrons around Mercury from kinetic particle modeling?1. Magnetosphere2. Particle motion3. Particle tracking simulation
1. The MagnetosphereIntrinsic Magnetic Field Solar Wind
cusp magnetotail
Mercury has a magnetosphere too!
2. Particle MotionLorentz Force
Gyro motionBounce motionDrift motion
𝑭= 𝑞(𝑬+ 𝒗× 𝑩)
3. SimulationLorentz force again
Numerical integration with Runga-Kutta
Can vary starting position, energy, pitch angle
𝑭= 𝑞(𝑬+ 𝒗× 𝑩)
𝑬= 0 𝑑𝒗𝑑𝑡 = 𝑞𝑚𝒗× 𝑩
Assumptions
No gravityE = 0Static B fieldCollision-free
motion
Collide with the planet
Escape into the magnetopause
Trapped
Single particle
Multiple particles (2730)
How many trapped
Loss cone
Collision with Planet
Trapped
Magnetopause
Comparison with Mariner 10Observation: Mariner saw bursts of energetic
particles with a period of 6 to 10 seconds.Explanations:
Theory 1: A series of substorms every 6 to 10 seconds cause electron bursts [ekhert et 1976]
Theory 2: A single substorm causes drift resonance – electrons orbit around Mercury once every 6 to 10 seconds.
Simulation: trapped 50-keV electrons have a period of about 30 seconds – rules out Baker.
Comparison with MESSENGER
ConclusionDeveloped a computational model to trace
particles in a model magnetic field.Expanded and parallelized the code to
incorporate a range of initial conditions. The results were consistent with observations
by Mariner and Messenger that implied an existence of a trapped electron population.