Question

Using the simple relationships given for relating the ranges of alpha particles to factors such as Z_abs, E_alpha, A_abs, calculate the range of 35.0-MeV alpha particles in an alloy consisting of 10% by weight of Be in Al. The alloy has a density of 2.32 g/cm³. Assume the absorption is dues to the ionization and scattering. Express your answer in both mass thickness units (mg/cm²) and micrometers.

Answer 1

The Bragg Kleeman rule can be applied to determine the range of heavy particle in a second material, if the range of a heavy particle can be determined in one material.


To determine the range of alpha particle in alloy we need to first determine the alpha particle range in air at temperature and 1 atm pressure which is approximated by:

Where Range in cm of air
Energy of alpha particle in MeV= 35.0 MeV

​From the relationship of range and density

density of air at STP

density of alloy

To determine in terms of mass thickness from the Bragg Kleeman rule

then substituting the

density

effective atomic mass of air

effective atomic mass of alloy

Therefore range of alpha particles in alloy in terms of mass thickness unit is 54.73 mg/cm2 and in terms of length units 439 micrometers.