Distinct state of matter, containing significant number of electrically charged particles to affect its electrical properties and behavior is called PLASMA.
Plasma Formation:
When more heat is applied, the atoms or molecules may be ionized. The atom loses one electron and develops a net positive charge. It becomes an ion. When gas is heated at very high temperature, ionization takes place that create clouds of free electrons and ions. This ionized gas mixture, containing ions, electrons and neutral atoms is called plasma.
Plasma Identification:
Plasma was identified by English scientist William Crookes in 1879.
Plasma Significance:
Plasma was estimated to constitute more than 99% of visible Universe. Although, naturally occurring plasma is on earth, there are many man-made examples. Plasma is being used to conduct electricity in neon signs and fluorescent bulbs. It occurs only in lightening discharges and in artificial devices like fluorescent lights, neon signs etc. It is everywhere in our space environment.
Potential of plasma:
- Plasma can generate explosions, freeze, carry electrical currents and support magnetic fields within themselves.
- Space plasma can contain enough heat to melt the earth thousands of times over.
- Crystal plasma can freeze the earth at least a hundred times, one after the other.
Natural plasma:
Natural plasma exists only at very high temperatures or low extremely hot (over 20,000°C minimum).
Artificial plasma:
Artificial plasma can be created by using electrical charges on a gas, as in neon signs. Plasmas at low temperatures hard to maintain because outside a vacuum low temperature plasma reacts rapidly with any molecules it encounters.
Characteristics of plasma:
- A plasma must have sufficient number of charged particles, so as whole it exhibits collective response to electric magnetic fields. The motions of particles in the plasma generate fields and electric currents form within plasma density. It refers to the density of the charged particles.
- Although plasma includes electrons and ions and conducts electricity, it is macroscopically neutral. In measurable quantities the number of electrons and ions are equal.
Existence of plasma:
Entire Universe is almost of plasma. Plasma are found in everything from sun to quarks (the smallest particles in the Universe).
In is the stuff of stars, a majority of the matter in inner-stellar space is plasma. All the stars that shine are all plasma.
On earth it only occurs in a few limited places like lightening both, flames auroras and fluorescent lights.
Applications of Plasma:
Plasma have numerous important technological applications in many devices. It helps us to understand much of the universe around us. Due to its conductive. Respond to electric and magnetic fields and can be efficient sources of radiations. The most important applications are:
- A fluorescent light is not like a regular light bulbs. As it contains gas electricity flows through the tube. The electricity acts as special energy to charge up the gas and hence exciting of the atoms creating a glowing plasma inside the bulb.
- ii) Plasma processing of semi-conductors, sterilization of some mechanical products, laps, lasers, diamond coated films, high power microwave sources and pulsed power switches.
- They also provide the foundation of important potential applications such as the generation of electrical energy from fusion pollution control, and removal of hazardous chemicals.
- Plasma light up our offices, homes and make our computers and electronic equipment work.
- They drive lasers and particle accelerators, help to clean up the environment, pasteurize foods and make tools corrosion resistant.
Future Horizons of Plasma:
Plasma would have to be low energy and should be able to survive without instantly reacting and degenerating. The magnetic field create low energy plasma which create molecules of Meta stable state.
The magnetic fields used to create the low temperature plasma give the plasma molecules electrons, which do not react until they collide with other molecules with the right energy. This enables these metastable molecules to survive long enough to react with a designated molecule.
These metastable particles are selective in their reactivity which make them a potentially unique solution to problems like radioactive contamination.
Work on mixture of gases as Meta stable agents on plutonium and uranium is on progress.
