Skip to main content Accessibility help
×
Hostname: page-component-7c8c6479df-995ml Total loading time: 0 Render date: 2024-03-28T02:34:51.977Z Has data issue: false hasContentIssue false

4 - Low-energy particle population

Published online by Cambridge University Press:  27 October 2009

Get access

Summary

Voyager 1 and 2 performed the first unambiguous low-energy (E ≥ 30 keV) ion measurements in and around the Jovian magnetosphere in 1979. The magnetosphere contains a hot (kT ~ 30 keV), multicomponent (H, He, O, S) ion population dominated by convective flows in the corotation direction out to the dayside magnetopause and on the nightside to ~ 130–150 Rj beyond which the ion flow direction changes to predominantly antisolar, but with a strong component radially outward from Jupiter. This tailward flow of hot plasma, the magnetospheric wind, accounts for the loss of ~ 2 × 1027 ions/s and ~ 2 × 1013 W from the magnetosphere. Comparison of energetic (≥ 30 keV) ion to magnetic field pressure reveals that particle and magnetic pressures are comparable from the magnetopause inward to at least ~ 10 Rj, that is, magnetosphere dynamics is determined by pressure variations in a high-β plasma. This particle pressure is responsible for inflation of the magnetosphere and it (rather than the planetary magnetic field) determines the standoff distance with the solar wind. The ion spectrum can be described by a convected Maxwellian component at E ≤ 200 keV, and a nonthermal tail at higher energies described by a power law of the form E−γ. New theoretical techniques were developed in order to interpret the low-energy solid-state detector measurements of temperature, number densities, pressures, and flow velocities in this novel hot-plasma environment.

Type
Chapter
Information
Publisher: Cambridge University Press
Print publication year: 1983

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×