Gamma Spectroscopy (NORM and TENORM)

Written and developed by Prof. Tor Bjørnstad (IFE/UiO) 

back to Naturally Occuring Radioactivity - NORM and TENORM

N =   number of nuclides
D =   disintegration rate (Bq, Ci, dimension s-1)
A =   activity is disintegration rate D per unit of volume or unit of mass (dimension s-1)
    We distinguish between two notions:
    As(i) = specific activity is activity per unit of mass of that particular element the actual
      radionuclide i belongs to. This notion is also used to express the activity of a
      particular radiolabelled molecule in relation to the total mass of the same molecule
      (labelled and unlabelled) in the sample (for instance when the inactive molecule is present
      as a carrier).
    Ac(i) = activity concentration is the activity of a special radionuclide i or all present
      radionuclides (AcT = A_c(∑i) = total activity) per unit of volume or unit of weight of a radioactive
      sample.

N,D and A may, in addition, have an index t (i.e. N_t, D_t and A_t). This denotes the parameter values at time t relative to a starting time t = 0.
R =   counting rate (cps, cpm or generally cpt where t should be defined, dimention s^-1)
S =   number of counts

N, D, A, R and S may, in addition, have indexes B = background, T = total or N = net. The relations between them are: R_N = R_T - R_B and S_N = S_T - S_B. Other indexes may also be used, for instance S_Cr-51 in order to separate from S_Fe-59.