The neon signs in the night are quite nostalgic. This billboard is quite popular a few decades ago, and now most of them have been replaced by LED and various large screens, but this unique style is still familiar to people. How does the neon tube glow? Essentially, it is similar to the principle of Aurora.
In the neon glass lamp tube in the packaging of certain types of thin gas, such as neon, helium, lamp at both ends with electrodes. The production of traditional neon lights, need to refer to the drawings of the glass tube heated into a variety of shapes:
Neon tube work, the need to add between the two electrodes high enough voltage (several thousand volts), in such a high voltage, some of the original neutral gas atoms will be ionized into a separate electronic, As well as positively charged ions. Under the action of high voltage, these charged particles will be accelerated, get higher kinetic energy, and collide with other atoms.
One of the consequences of the collision is that the atom to be hit is not completely ionized, but the electrons are excited to enter the excited state of higher energy. The next thing sounds familiar: the excited electrons can return to the ground state and release the extra energy in the form of photons, so the neon lights to light. The color of the light depends on the type of excited gas, such as neon lights with neon is beautiful orange red:
If you add fluorescent material in the inner wall of the lamp, but also to further adjust the color of light, fluorescent tube is also such a way to take.
The aurora is also a similar process: some of the gas atoms in the atmosphere by the impact of charged particles into the excited state, and after the excitation of the corresponding color of the light emitted. But this time the source of the charged particles is the sun.