Plasma parameters

The plasma parameters in the physics of plasmas a possible size for categorization: for a gas called plasma. It is a dimensionless number of particles and results from the multiplication of the particle density of the plasma by the spherical volume of the Debye length : ${\displaystyle N_{D}}$ ${\displaystyle N_{D}\gg 1}$ ${\displaystyle n}$ ${\displaystyle \lambda _{D}}$

${\displaystyle N_{D}=n\cdot {\frac {4}{3}}\pi \lambda _{D}^{3}.}$

It thus indicates how many particles are inside the Debye sphere. The more particles this applies, the stronger the electrical fields of the electrons and ions in the plasma are shielded, which leads to quasi-neutrality .

Typical values ​​for the plasma parameter are:

Plasma type	Plasma parameters ${\displaystyle N_{D}}$
Fusion plasma	${\displaystyle 6\times 10^{11}}$
Interstellar matter	${\displaystyle 2\times 10^{5}}$
ionosphere	${\displaystyle 5\times 10^{4}}$
Gas discharge	${\displaystyle 2\times 10^{4}}$

Further information

• Ulrich Stroth: Plasma Physics . 1st edition. Vieweg + Teubner, Wiesbaden 2011, ISBN 978-3-8348-1615-3 .