A gamma ray from 198Au incident normally on a thick aluminum slab travels 1.45 cm before it undergoes a Compton scattering. Calculate the range of angles through which the gamma could scatter and still have at least a 10% probability of re-emerging from the incident slab surface without undergoing another interaction.
the mass attenuation coefficient for Al at 1.5 cm is .05 MeV
E[tex]\gamma[/tex]' = Ey / [1 + (E[tex]\gamma[/tex]/E0) (1-cos[tex]\vartheta[/tex])
The Attempt at a Solution
IIn the chart of the nuclides do I use one of the gamma energies or is this even the first formula I should be using?