Transmission Fraction – the fraction of the beam that penetrates the block

TF = 2^-n

(n) = block thickness / half value thickness

with the Transmission Fraction (TF) we can write a simple equation to solve for the final intensity given the initial intensity with blocking:

I_f = (TF) I_f

Half Life (T ½) – the amount of time that is required to reduce the radioactivity to ½ of its present value

The halflife for radioactive radon gas is 3.83 days

from the derivation above we get the value for Lambda (l) or Decay Constant

Decay Constant – the percent reduction per unit of time

• Is dependent on the radioactive element

Activity Fraction (AF) – the fraction of the activity that is remaining after a given amount of time

AF = 2^-n

n = time / half life

with the Activity Fraction (AF) we can write a simple equation to solve for the final activity if we are given the initial activity:

A_f = (AF) A_i