Plasma physics

Plasma physics. It is a gas made up of free charged particles (ions) and whose dynamics have collective effects dominated by long-range electromagnetic interactions between them.

Summary

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  • 1 History
  • 2 Features
  • 3 Studies and results
  • 4 Sources

History

When the blood is removed every cell is a clear liquid, called “plasma” by the great Czech medical scientist Johannes Purkinje ( 1787 – 1869 ).

The use of the term “plasma” to name an ionized gas began in 1927 by Irving Langmuir ( 1881 – 1957 ), an American whose successes ranged from surface chemistry to cloud seeding to rain. He won the Nobel Prize in Chemistry in 1932 . Langmuir worked for the General Electric Co., studying electronic devices based on ionized gases. The way that electrified fluids carried high-speed electrons, ions, and impurities reminded him of the way that blood plasma carries red and white blood cells , and germs .

characteristics

In Physics and Chemistry , plasma is said to be a gas made up of free charged particles (ions) and whose dynamics have collective effects dominated by long-range electromagnetic interactions between them. Plasma is often referred to as a state of aggregation of matter with its own characteristics, thus differentiating it from the gaseous state, in which there are no significant collective effects.

Studies and results

As a consequence of these studies, carried out on relatively cold and dense plasmas, scientists now speak of “Langmuir waves” and fly “Langmuir probes” aboard satellites. Plasma research progressively progressed in other directions, of which three were especially significant.

First, the development of radio led to the discovery of the Ionosphere , the natural “plasma ceiling” above the atmosphere, which bounces and sometimes absorbs radio waves. Beginning with the study of radio wave propagation in the ionosphere, a wide variety of plasma waves were identified, generally dispersing differently along magnetic field lines rather than perpendicular to them.

Second, astrophysicists admitted that much of the universe was made up of plasmas and that knowledge of astrophysical processes required a better understanding of plasma physics . This was particularly true for the Sun , whose intensely magnetic spots produced many complicated magnetic phenomena (eg solar flares).

Ultimately, the creation of the atomic bomb raised interest in nuclear power as a possible source of energy for the future. The Sun releases its energy by combining hydrogen nuclei to form helium , but its thermonuclear fusion process requires enormous temperatures and pressures, such as those that occur in the center of the Sun. The process is easier in a gas formed by larger forms ( isotopes) of hydrogen, but still such enormous temperatures were needed that there was no laboratory container to enclose the gas, the container would vaporize or (more likely) cool the gas until all nuclear fusion ceased.

However, since gas at such temperatures is converted to plasma, the idea arose to confine it within a magnetic field, without actually touching any material walls. The possibility of producing such “controlled thermonuclear fusion” began with the “Sherwood Project” in the early 1950sand it grew to become a large international company, with thousands of scientists and enormous and sophisticated devices. Little by little, ways were found to eliminate the different means by which the magnetic field allowed its plasma to leak rapidly and its temperature and density gradually increased. An experiment was recently carried out to extract as much fusion energy as that invested in plasma, but it will still take a long time to obtain commercial use of this form of energy.

When the satellites discovered the radiation belt and began exploring the magnetosphere, a fourth path opened up, space plasma physics. Space scientists borrowed, from fusion research, the theory of plasma trapped by a magnetic field, and the theory of plasma waves, from the physics of the ionosphere. Astrophysics provided, among other things, the notions of magnetic energy release processes and particle acceleration. Today plasma physics is an active field, which contributes to the knowledge not only of spatial observations, but also of plasmas in general.

 

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