Albert J. M., Y. Y. Shprits, (2009), Estimates of lifetimes against pitch angle diffusion, Journal Of Atmospheric And Solar-terrestrial Physics, 71, 1647 – 1652, doi:10.1016/j.jastp.2008.07.004, Toward an Integrated View of Inner Magnetosphere and Radiation Belts

## Abstract

We consider timescales on which particle distributions respond to pitch angle diffusion. On the longest timescale, the distribution decays at a single rate independent of equatorial pitch angle α0, even though the diffusion coefficient, and the distribution itself, may vary greatly with α0. We derive a simple integral expression to approximate this decay rate and show that it gives good agreement with the full expression. The roles of both the minimum and loss cone values of the diffusion coefficient are demonstrated and clarified.## Authors (sorted by name)

Albert Shprits## Journal / Conference

Journal Of Atmospheric And Solar-terrestrial Physics## Acknowledgments

We thank Michael Schulz for useful discussions. This work was supported by the Space Vehicles Directorate of the Air Force Research Laboratory and by NASA grants NNX08AF34G and NNX06AB84G.## Grants

NNX06AB84G NNX08AF34G## Bibtex

@article{ALBERT20091647,
title = "Estimates of lifetimes against pitch angle diffusion",
journal = "Journal of Atmospheric and Solar-Terrestrial Physics",
volume = "71",
number = "16",
pages = "1647 - 1652",
year = "2009",
note = "Toward an Integrated View of Inner Magnetosphere and Radiation Belts",
issn = "1364-6826",
doi = "10.1016/j.jastp.2008.07.004",
url = "http://www.sciencedirect.com/science/article/pii/S1364682608001818",
author = "J.M. Albert and Y.Y. Shprits",
keywords = "Pitch angle diffusion, Lifetime, Decay rate",
abstract = "We consider timescales on which particle distributions respond to pitch angle diffusion. On the longest timescale, the distribution decays at a single rate independent of equatorial pitch angle α0, even though the diffusion coefficient, and the distribution itself, may vary greatly with α0. We derive a simple integral expression to approximate this decay rate and show that it gives good agreement with the full expression. The roles of both the minimum and loss cone values of the diffusion coefficient are demonstrated and clarified."
}