International Science Community Association Research Journal of Chemical Sciences 2231 - 606X 1 2 2011 May 18 Variation of Effective Atomic Numbers of some Thermoluminescence and Phantom Materials with Photon Energies 64 69 EN Manocha N. 1 Swami Vivekanand college of Pharmacy, Indore, INDIA Chandra S.K. 2 Suresh Gyan Vihar University, Jaipur, INDIA Sharma V. 3 B.M College of Pharmaceutical Sciences, Indore, INDIA Sangameswaran B. 4 Saluja M. 5 Sathyaraj A. 1 Swami Vivekanand college of Pharmacy, Indore, INDIA Satyanarayana V. 2 Suresh Gyan Vihar University, Jaipur, INDIA Rao M.V.Basaveswara 3 B.M College of Pharmaceutical Sciences, Indore, INDIA Pruthviraj R.D. 1 Dept. of Chemistry, Amruta Institute of Eng. and Mangt. Sci., Bidadi, Bangalore, INDIA Rao G.V. 1 CavinKare Research Centre, 12, Poonamalle Road, Ekkattuthangal, Chennai-600 032, INDIA Annamalai T. 2 Mukhopadhyay T. 3 Madhavi S 4 Machavolu Lakshmi 5 Mbabazi Jolocam 1 Department of Chemistry, Makerere University, P.O. Box 7062, Kampala, UGANDA Ntale M. 2 Department of Chemistry, Kyambogo University, P.O. Box 1, Kyambogo, UGANDA Kwetegyeka J. 3 Department of Chemistry, Gulu University, P.O. Box 166, Gulu, UGANDA Mulongo G. 4 Twinomuhwezi H 5 Nnamuyomba P. 6 Benarjiand K.V. PatruduT. 1 Dept. of Chemistry, College of Eng., GITAM University, Hyderabad campus, Visakhapatnam, INDIA SangerS. H. 1 Dept. of Elec. and other Energy Sources, College of Agri. Eng. and Tech. DBSKKV, INDIA Mohod A.G. 2 Y.P. Khandetode 3 H.Y. Shrirame 4 Deshmukh A.S. 5 hivaraju P.H 1 Dept. of Environmental Science, Yuvaraja Collage, University of Mysore, Mysore, INDIA Olarinoye I.O. 1 Department of Physics, Federal University of Technology, Minna, NIGERIA > Research Paper 2011 4 07 2011 May 18 Effective atomic numbers (Zeff) of 15 materials (CaSO, nylon, methyl but-3-enoate, mylar, C4, Al, SiO, stearate, CH, CaF2 water, Iron sulphate, polystyrene, polyvinyl, and potassium calcium sulphate) used in dosimetry and substitute materials were calculated using standard formula based on their mass attenuation coefficients (µ). The µ of the materials were obtained for photon energies of 0.01 KeV to 20 MeV using WinXCOM. Generally, Zeff for each of the substances considered is not a constant but varies with photon energy. Zeff varies from11-17 for CaSO, 3-6 for nylon, 6-7 for methyl but-3-enoate, 4-7 for mylar, 8-9 for C4, 10-12 for Al, 10-12 for SiO, 3-6 for stearate, 2-5 for CH, 13-18 for CaF2 3-8 for water, 12-23 for Iron sulphate, 4-6 for polystyrene, 5-16 for polyvinyl, and 12-17 for potassium calcium sulphate. The variations of Zeff with photon energy for all the 15 substances follow similar pattern. The variations were dictated by photon interaction processes. The highest value of Zeff for all the materials was obtained at the lowest energy, while the lowest value was obtained between 0.1 and 1.5 MeV. The mean atomic number of each compound was also found to be equal to the eff obtained at intermediate energies of the energy spectrum considered (0.1 MeV -1.5 MeV). The upper and lower limit of Zeff for each of the considered materials was found to be dictated by the atomic numbers of the constituent elements of the materials. Copyright@ International Science Community Association