Development and Application of Stochastic Methods for Radiation Belt Simulations

Simple item page
dc.contributor.advisorChan, Anthony Aen_US
dc.contributor.committeeMemberWolf, Richard Aen_US
dc.contributor.committeeMemberDugan, Brandonen_US
dc.creatorZheng, Lihengen_US
dc.date.accessioned2016-02-05T21:29:41Zen_US
dc.date.available2016-02-05T21:29:41Zen_US
dc.date.created2015-12en_US
dc.date.issued2015-09-04en_US
dc.date.submittedDecember 2015en_US
dc.date.updated2016-02-05T21:29:41Zen_US
dc.description.abstractThis thesis describes a method for modeling radiation belt electron diffusion, which solves the radiation belt Fokker-Planck equation using its equivalent stochastic differential equations, and presents applications of this method to investigating drift shell splitting effects on radiation belt electron phase space density. The theory of the stochastic differential equation method of solving Fokker-Planck equations is formulated in this thesis, in the context of the radiation belt electron diffusion problem, and is generalized to curvilinear coordinates to enable calculation of the electron phase space density as a function of adiabatic invariants M, K and L. Based on this theory, a three-dimensional radiation belt electron model in adiabatic invariant coordinates, named REM (for Radbelt Electron Model), is constructed and validated against both known results from other methods and spacecraft measurements. Mathematical derivations and the essential numerical algorithms that constitute REM are presented in this thesis. As the only model to date that can solve the fully three-dimensional diffusion problem, REM is used to study the effects of drift shell splitting, which gives rise to M-L and K-L off-diagonal terms in the radiation belt diffusion tensor. REM simulation results suggest that drift shell splitting reduces outer radiation belt electron phase space density enhancements during electron injection events. Plots of the phase space density sources, which are unique products of the stochastic differential equation method, and theoretical analysis further reveal that this reduction effect is caused by a change of the phase space location of the source to smaller $L$ shells, and has a limit corresponding to two-dimensional local diffusion on a curved surface in the (M,K,L) phase space.en_US
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationZheng, Liheng. "Development and Application of Stochastic Methods for Radiation Belt Simulations." (2015) Diss., Rice University. <a href="https://hdl.handle.net/1911/88411">https://hdl.handle.net/1911/88411</a>.en_US
dc.identifier.urihttps://hdl.handle.net/1911/88411en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.subjectradiation belten_US
dc.subjectelectron diffusionen_US
dc.subjectFokker-Planck equationen_US
dc.subjectstochastic differential equationen_US
dc.subjectmodelingen_US
dc.titleDevelopment and Application of Stochastic Methods for Radiation Belt Simulationsen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentPhysics and Astronomyen_US
thesis.degree.disciplineNatural Sciencesen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.majorSpace Physicsen_US
thesis.degree.nameDoctor of Philosophyen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
ZHENG-DOCUMENT-2015.pdf
Size:
7.33 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 2 of 2
No Thumbnail Available
Name:
PROQUEST_LICENSE.txt
Size:
5.83 KB
Format:
Plain Text
Description:
Download
No Thumbnail Available
Name:
LICENSE.txt
Size:
2.6 KB
Format:
Plain Text
Description:
Download
Collections
Rice University Theses and Dissertations