This picture shows that there is a small region in which the particles are trapped into a plasmasphere.
Click on image for full size
T.S. Huang
Uranus' Plasmasphere
Uranus' plasmasphere is tiny. The rings of Uranus sweep away much of the particles in the area.
Particles enter the plasmasphere from the atmosphere as well as the magnetotail. Mathematical theory suggests that particles leave the plasmasphere by being swept directly into the atmosphere.
This picture shows that there is only a small region in which the particles are trapped. This region is the plasmasphere.
You might also be interested in:

Uranus' plasmasphere is tiny. The rings of Uranus sweep away much of the particles in the area. Particles enter the plasmasphere from the atmosphere as well as the magnetotail. Mathematical theory suggests
...more
There is not very much radio noise within the magnetosphere of Uranus. Signals are observed with much less power than observed at Saturn, but several times greater than observed at Earth. The signals
...more
Besides methane, Uranus' atmosphere contains even more complex molecules. These molecules form layers of smog over the clouds of Uranus, as shown in the picture.
...more
The mesosphere of Uranus is a region of balance between warming and cooling. That essentially means that nothing happens there. Except for diffusion, the atmosphere is still. Upper reaches of the atmosphere,
...more
As on Earth, the atmosphere of Uranus consists of a troposphere, stratosphere, mesosphere, and thermosphere. The troposphere is the region where the visible clouds are to be found. The stratosphere, as
...more
On Uranus, as on Jupiter, the winds in the belts and zones blow first in one direction, then in the other direction. The clouds rise up in a belt, and drop down in a zone, as shown in this picture. This
...more
The clouds on Uranus, like Jupiter, are divided into stripes. On Uranus the stripes are hard to find. The left picture shows the north pole of Uranus. In this picture only the smog can be seen. The clouds,
...more