What is the plasma which is referred to as 'the fourth state of matter' next to solid, liquid and gas?

By Jared Tarbell

Everyone knows that it will turn into ice if it cools down water, if it melts it becomes water, and if it is heated as it is it will become water vapor. And as heating continues to a higher temperature, the water molecules change to the plasma state where cations and electrons are separated. Although it is a plasma that we do not usually see much, in fact it is said to be "the most common substance in the universe", and it is said that 99% of the material in the universe is in the state of plasma.

Plasma, the mysterious (and powerful) fourth phase of matter | Aeon Ideas

The most common plasma that you usually see is lightning. Lightning is a phenomenon in which the electric potential accumulated in the accumulation is blown up at once because the electric potential difference between the earth's surface and the sky becomes large and the insulation of the air layer that does not pass electricity is broken, and the part of the air that passed was several hundred million degrees It will be in an extremely hot condition. "Lightning" visible when lightning strikes is a state in which the atmosphere ionized by this super high temperature and high voltage is in a plasma state and is emitting light.

Also, although there is little to see when you are in Japan, "Aurora" which often occurs in places with high latitudes is also one of the plasmas. The aurora is a phenomenon in which the electron beam supplied from the solar wind that jets out from the sun and flew to the earth descends along the geomagnetism and the oxygen or nitrogen in the atmosphere excited by the electron beam is emitted.

By Heikki Holstila

In order to generate plasma, it is necessary to activate the molecule extremely by setting the substance to a very high temperature. "Temperature" of a substance in thermodynamic terms refers to the kinetic energy (vibration) of the atom or molecule that is the source of the substance. The temperature of the material increases from absolute zero to millions of degrees, sometimes to hundreds of millions of degrees, where the vibration of the molecule stops, and the vibration of atoms and molecules increases accordingly. Plasma is a phenomenon caused by ionization of molecules by this high kinetic energy.

Plasma research is being carried out in many countries around the world with much budget. What motivates it is the goal of realizing "controlled thermonuclear fusion" by human hands. Fusion power generation utilizing the enormous energy generated when the two nuclei fuse together is regarded as a "clean" energy source that scarcely emits radioactive waste like nuclear power generation, and it is drawing attention as a future energy source .

However, in order to realize nuclear fusion on the ground, it is necessary to keep the plasma at a high temperature of over 100 million degrees Celsius. This is actually a world that is ten times hotter than the center of the sun, but in reality this goal has been achieved in the 1990s. The real challenge, that is where the high temperature plasma is very unstable.

By Image Editor

In the 1950s research was carried out secretly in the Soviet Union, the United Kingdom, and the United States. Princeton University is the center of this research in the United States, and physicist Dr. Lyman Spitzer launched Project Matterhorn. In this project, research on a method of creating a "confining magnetic field" by winding a twisted coil called "stellarator method" to create an environment in which nuclear fusion occurs is advanced. Ultimately the project never succeeded in fusion, but we gained the know-how to stably generate plasma.

On the other hand, the Soviet scientists were developing another device called " Tokamak type ". Designed by physicist Dr. Andre Saharov and Dr. Igor Tam , this device was able to keep the plasma stable at higher temperatures than the stellarator type. Thereafter, this tokamak type device is mainly used in nuclear fusion research, and consortiums of China, the European Union, India, Japan, Korea, Russia and the United States joined in 2015, and the world's largest tokamak type Atoms are to be constructed.

By Oak Ridge National Laboratory

It is an indispensable plasma in the field of nuclear fusion, but it is also closely intertwined with the physics of the space surrounding the earth. Harmful "cosmic rays" coming from space are always falling on the earth, but this is charged plasma particles. The magnetic field of the earth plays a role of bouncing back plasma particles, creating an environment where life can live forever.

Also, in a new field called "space weather", plasma physics plays a similar role as the role of fluid dynamics in the weather forecast of the earth. There are many parts that have not been clarified yet in this field where research is underway, but elucidating the universe scale event that greatly influences the earth's environment such as "solar flare", high energy particles rain down It is also thought to make it possible to predict "Solar Storm".

Luca Comisso, a postdoctoral fellow at the Columbia Astrophysics Laboratory at Columbia University, says, "Plasma physics is expected to provide insight into how stars, galaxies and clusters were originally formed. According to a cosmological model, a high temperature plasma was spreading in the early universe, then everything began to cool down, electrons and protons were combined and an electrically neutral hydrogen atom was created. The state continued until the first star and the black hole was formed, then the space was "re-ionized" and mostly returned to the plasma state, "plasma helps to unravel the mystery of the universe I believe.

By tackyshack

in Science, Posted by darkhorse_log