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5.2
Required quantities: Particle number
More general, in a time
independent
situation the number
N
may be described within a six dimensional
phase space
(x;
Ω
;E) in which:
x = (x1; x2; x3) is the spatial coordinate,
Ω
is the particle direction which is a point on a unit sphere S
with the angles coordinates
ϕ
and
θ
E is the energy variable.
E), , z, y, x,(
θϕ
NN
=