plasma
- Domaine
-
- chimie
- Date
Définition :
Nom donné aux gaz ou aux vapeurs dont les atomes ou molécules sont ionisés. Ces plasmas sont conducteurs de l'électricité.
Terme :
- plasma n. m.
Traductions
-
anglais
Date :Définition
A gas which has been heated to such a degree [upwards of 5500 °C (10,000 °F)] that electrons are pulled away from the atoms by the force of the greatly intensified collisions, leaving them in an ionized state. The gas then is made up of a mixture of electrons and ionized nuclei which behave quite differently from gases at normal temperatures.
Note :
It is believed that this was the original state of matter in the universe. Though plasmas exist naturally only in the sun and starts, they can be produced on earth by nuclear fission, and by subjecting gases to electromagnetic fields of high intensity. Plasmas are conductors of electricity and are responsive to magnetic fields. As a result of scientific study of this behavior, an area of physical chemistry has developed called magnetohydrodynamics, in which matter in the plasma state is regarded as an electrically conducting fluid. Controlled fusion reactions also involve use of plasma.
Terme :
- plasma