Plasma (physics) potential in the space between charged particles, independent of how it can be measured, is called the "plasma potential", or the "space potential". If an electrode is inserted into a plasma, its potential will generally lie considerably below the plasma potential due to what is termed a Debye sheath. The good electrical conductivity of plasmas makes their electric fields very small. This results in the important concept of "quasineutrality", which says the density of negative charges is approximately equal to the density of positive charges over large volumes of the plasma (formula_6), but on the scale of the Debye length
Positive and negative parts Positive and negative parts In mathematics, the positive part of a real or extended real-valued function is defined by the formula Intuitively, the graph of formula_2 is obtained by taking the graph of formula_3, chopping off the part under the "x"-axis, and letting formula_2 take the value zero there. Similarly, the negative part of "f" is defined as Note that both "f" and "f" are non-negative functions. A peculiarity of terminology is that the 'negative part' is neither negative nor a part (like the imaginary part of a complex number is neither imaginary nor a part). The function "f" can