20. Practical Implications (electrons): This leads to dosimetric inaccuracies when using air containing ion chambers. Polarization in heavier atomic weight elements. This leads to a “smudging” of the Bragg's peak which is not seen in electrons. The low mass of the electron leads to greater scattering. This is of practical importance as radioactive isotopes which are produce high energy beta radiation are better stored in low atomic number materials e.g. plastics as they will lead to lesser bremsstrahlung radiation. Also higher atomic number elements are better for x ray production. The amount of radiative loss is proportional to the square of the atomic number of the material This leads to the phenomenon of greater ionization in soft tissues relative to bones. Ionization and excitation are more for low atomic materials