269 / 1542
Charged Particle (=Electronic) Equilibrium
Charged particle equilibrium
(CPE) exists if for each charged particle with
energy
E leaving a volume
, there is an
identical
particle with
same
energy
E entering that volume
Low
energy beam enters surface:
KERMA
is max because fluence is
greatest at surface
Low
energy beam:
KERMA = Dose
because the energy is deposited at the
interaction point
Dose
Collision Kerma
depth
Dose (Gy)
Low
energy
Ignoring brehmsstralung