Plasma Dickson Lim(14) 1p2

Content  Brief introduction  Formation of Plasma  Definition of Plasma  Properties  Common Plasma  Plasma  Uses of Plasma  Plasma TV  Interesting facts  Photo Gallery

Brief Introduction to Plasma  Very similar to gas  -certain particles are ionized  Has properties quite unlike those of solids, liquids, or gases  Considered to be a distinct state of matter  4 th state of matter

Formation of Plasma  A plasma is an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both species, ions and electrons, to coexist.  A plasma is a gas that has been energized to the point that some of the electrons break free from, but travel with, their nucleus.

Formation of Plasma  The energy can be of various origins: thermal, electrical, or light  E.g. ultraviolet light or intense visible light from a laser.  With insufficient sustaining power, plasmas recombine into neutral gas.

Definition of Plasma  Charged particles must be close enough together that each particle influences many nearby charged particles  (rather than just interacting with the closest particle)  Interactions in the bulk of the plasma are more important than those at its edges, where boundary effects may take place.

Properties Does not have a definite volume Does not have a definite shape Can be compressed

Common Plasma  Are by far the most common phase of matter in the universe, both by mass and by volume.  All the stars are made of plasma, and even the space between the stars is filled with a plasma, albeit a very sparse one.  In our solar system, the planet Jupiter accounts for most of the non-plasma, only about 0.1% of the mass and 10 −15 % of the volume within the orbit of Pluto.

Plasma  By far the most common form of matter  Present in the stars and in the tenuous space  Makes up over 99% of the visible universe and perhaps most of that which is not visible

Plasma  Consists of a collection of free moving electrons and ions - atoms that have lost electrons.  Energy is needed to strip electrons from atoms to make plasma.  The energy can be of various origins: thermal, electrical, or light.  With insufficient sustaining power, plasmas recombine into neutral gas.

Plasma  Can be accelerated and steered by electric and magnetic fields  Allows it to be controlled and applied.  Temperature commonly measured in kelvins or electronvolts  Informal measure of the thermal kinetic energy per particle.

Plasma  Can be accelerated and steered by electric and magnetic fields  Allows it to be controlled and applied.  Temperature commonly measured in kelvins or electronvolts  Informal measure of the thermal kinetic energy per particle.

Uses  Mainly used in high tech industries  Microelectronic/semiconductors  chips for computers  transmitters for microwaves or high temperature films  Can even be used in extraction of minerals  e.g.diamond  Plasma TV

Plasma TV  A plasma display panel (PDP) is a type of flat panel display common to large TV displays.  Many tiny cells between just two panels of glass hold a mixture of noble gases.  The gas in the cells is electrically turned into a plasma which emits ultraviolet light which then excites phosphors to emit visible light.

Pros & Cons of Plasma TV  Advantages  Achieves better and more accurate color reproduction than LCDs  Produces deep, true blacks allowing for superior contrast ratios (up to 1:2,000,000)  Far wider viewing angles than those of LCD  Disadvantages  Susceptible to screen burn-in and image retention  Gradual decline of absolute image brightness  Use more electricity, on average, than an LCD TV

Lightning  Lightning is an example of plasma present at Earth’s surface  Typically, lightning discharges 30,000 amperes at up to 100 million volts, and emits light, radio waves, X-rays and even gamma rays  Plasma temperatures in lightning can approach ~28,000 kelvin and electron densities may exceed m −3

Tycho’s Supernova  The remnant of "Tycho's Supernova", a huge ball of expanding plasma  The outer shell shown in blue is X-ray emission by high-speed electrons.

Video  nWbnQ nWbnQ Tychos’s Supernova Please click the picture to watch the video

Sun  The biggest chunk of plasma you will see is that dear friend to all of us, the sun.  The sun's enormous heat rips electrons off the hydrogen and helium molecules that make up the sun.  Essentially, the sun, like most stars, is a great big ball of plasma.

Photo Gallery

Credits   ml ml   (video)