| The Sun and the Earth's Ionosphere | The CRT's Electron Gun | |
|
|
 |
|
| There are two ways in
which the particles that create the aurora come. They
can come from the Earth's ionosphere and from the Sun's solar wind.
The majority of the particles actually come from the Earth's ionosphere. The ionosphere is the uppermost layer of the Earth's atmosphere. In this region, ultraviolet light from the Sun provides energy to ionize atoms. The excited atoms separate into positive ions and negative electrons. This conditions is referred to as a "plasma". The plasma state is often called the fourth state of matter. |
In
order to understand how a CRT works, we must first look at a few of its
major components.
At the back of the CRT, a coiled filament heats up a piece of metal called the cathode. The cathode acts like the sun’s surface or the Earth's ionosphere under ultraviolet light, producing ions and electrons. These electrons are attracted to a positively charged metal cylinder called the anode. Together, the anode and cathode create a device called an "electron gun." |
