In my last post, I talk about the role of electronic technology in our daily life and its importance, and this is our second post about electronics. In this post, I am writing about Electron Emission and their types with a big try to explain it to you in sample words.
In this post we will disuse the following topics:
- What is Electronic Emission?
- Thermionic Or Primary Emission
- Secondary Emission
- Photo Electric Emission
- Field Emission
What is Electron Emission?
We also know that electrons which separate from the atom’s outer shell electron is called atom-free electrons, note that due to these free electrons’ flow the current flow is possible in wires, transistors and valves.
Every conductor’s free electrons are moving or surrounding the atom’s outer shell electron, These free electrons are not emitting themselves from the metal surface because the metal surface force stop escaping electrons at normal temperature.
It means that without applying force the free electron not escaping from metal.
When we provide some extra energy, the electron absorbs the energy and due to this observation, its kinetic energy become cress and the free electron is able to emit from the metal surface. This emitting is called electronic emission.
Types Of Electron Emission
For Escaping electrons from any conductor or metal, we use 4 different methods which are below.
Thermionic – Primary Emission
The method of Electron emission we use more than other methods of emission. In this method, we provide heat to metal for emitting free electrons from the metal surface, due to temperature, the free electron kinetic energy and thermal energy in cress and electron start escaping from the metal surface. If you provide more temperature, the electron will emit more, which means that temperature increases and decreases have a big link with electrons.
This method of emission is just like the liquid evaporation method.
Introduction to Electronics technology – Beginners Guide
Secondary Emission :
When a moving particle bombardment on a metallic surface and provides maximum- energy to make free electrons able to break the energy bears- for escaping is called secondary emission.
In other words in this method high-velocity electrons bombardment the cathode to make escaping electrons from the cathode. This method is called the secondary emission of electrons.
In this method, the E mission is done by providing light energy. In this type of emission, we provide light or we do lighting on a specific metal surface, the light energy transfer to the metal’s internal free electrons, due to this ‘the electron kinetic energy or speed in cress of electrons and it starts escaping from metal. This type of electron emission is called photoelectric emission.
We also called cathode emission field emission. We also know that electron is negatively charged particles and when we provide a high positive field to electrons, the electrons get compatible energy and it’s able to discharge.
Using a strong magnetic field for emitting electrons is called field emission.