ABSTRACT
The mass collision stopping power formula for heavy charged particles was derived by H.A. Bethe using relativistic quantum mechanics.
d d
4 ln
2 1
2 2S E
x r mc z ZN
A mc
I ( )ρ = − ρ = pi
β β
− β − β (9.1)
where β = V/c is the ratio of particle velocity to the velocity of light. This is represented, if the mass of particle, M, and the kinetic energy, T, are used, as
2Mc T Mc
β = − +
(9.2)
and mc2 = rest energy of an electron, re = e2/mc2 = classical electron radius, z = charge of heavy charged particle, Z = atomic number of the target atom, A = atomic mass of the target atom, NA = Avogadro constant, and I = mean excitation energy of medium.
