Thursday, October 2, 2008

Fundamentals: Decay rate

Decay rate and rate of decay and activity mean the same thing. It is number of particles disintegrating per second. If each dsintegration gives off energy E , the power of the radioactive source is P = AE , where A is the activity.
Using A = (decay constant) N , then N is the number of undecayed atoms present in the source at that moment. N can be easily converted to mass by multiplying by mass of atom in kg (converted by multiplying by 1.66 x10 -27kg )