Compact Plasma and Focused Ion Beams

6 Compact Plasma and Focused Ion Beams

attracted to the vicinity of an electron and shield its electrostatic

eld from the rest of the plasma.

Therefore, charged particles arrange themselves to shield all elec-

trostatic elds within a distance of the approximate Debye’s length.

The electrostatic potential of an isolated particle of charge q is

φ

= q/r.

Because of the shielding effect, the potential in the vicinity of the

charged particle in a plasma is altered and therefore the potential of

a charge at rest in a plasma is given by

j

l

=

−

q

r

e

r

D

/

.

(1.8)

In other words, in the neighborhood of any surface inside the

plasma, there is a lay ...