402 / 881
Energy lost = Dose deposition
• Heavy charged particle follow the Bethe-Bloch formula:
(
)
+ −
⋅
−
⋅
⋅
⋅ ⋅
=
−
SDBB
I
W cm
A
Z z K
ds
dE
e
2
2
2
max
2 2
2
2
1
2 ln
2
1
1
β
β
β
β
ρ
• First approximation:
1/
v
2
Bragg peak
H. Bethe: Annalen der Physik. 397, Nr. 3, 1930