Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1875757 | Applied Radiation and Isotopes | 2016 | 10 Pages |
Abstract
Response function of a widely used 3 inÃ3 in NaI(Tl) detector is constructed to correct the observed pulse height distribution. A 10Ã10 inverse matrix is constructed using 7 mono-energetic gamma sources (57Co, 203Hg, 133Ba, 22Na, 137Cs, 54Mn and 65Zn) which are evenly spaced in energy scale to unscramble the observed pulse height distribution. Bin widths (E)1/2 of 0.01 (MeV)1/2 are used to construct the matrix. Backscattered photons for an angle of 110° are obtained from a well-collimated 0.2146 GBq (5.8 mCi) 137Cs gamma source for carbon, aluminium, iron, copper, granite and Portland cement. For each observed spectrum, single scattered spectrum is constructed analytically using detector parameters like FWHM, photo-peak efficiency and peak counts. Response corrected multiple scattered photons are extracted from the observed pulse height distribution by dividing the spectrum into a 10 Ã1 matrix. Saturation thicknesses of carbon, aluminium, iron, copper, granite and Portland cement are found out. Variation of multiple scattered photons as a function of target thickness are simulated using MCNP code. A relationship between experimental and simulated saturation thicknesses of carbon, aluminium, iron and copper is obtained as a function of atomic number. Using this relation, effective atomic numbers of granite and Portland cement are obtained from interpolation method. Effective atomic numbers of granite and Portland cement are also obtained by theoretical equation using their elemental composition and comparing with the experimental and simulated results.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Radiation
Authors
K.U. Kiran, K. Ravindraswami, K.M. Eshwarappa, H.M. Somashekarappa,