Stopping Power:

Stopping power or LET (linear energy transfer) is the energy lost per unit path length. Given Equation 1 will expresses this relationship.

S = LET = ?E /?X                                                          (1)

where

S          = denotes stopping power

LET = linear energy transfer

?E       = energy lost

?X       = path length of travel

Specific ionization times the energy per ion pair yields the stopping power (LET), as shown in Equation 6-3.

S = (ion pairs/ path length)( energy/ ion pairs)                       (2)

= energy/ path length

S Stopping power, or LET, is proportional to the specific ionization.