Gamma radiation shielding characteristics of some soft and hard woods of medicinal plants from Nallamala forest of Andhra Pradesh

Wood is a complex biomaterial useful for various applications. Wood can also be used to shield radiation from nuclear sources. In the present study, the radiation effects on various wood materials of medicinal plants collected from Nallamala forest in Andhra Pradesh, India was investigated. Gamma radiation shielding characteristics such as linear attenuation coefficient, mass attenuation coefficient, half- value thickness and relaxation length of ten different types of wood materials were measured for gamma energies 511, 662, 1173, 1275 and 1332 keV from 22Na, 137Cs and 60Co radioactive sources . Measurements were performed using a gamma spectrometer consisting of NaI (Tl) scintillation detector coupled to an 8K PC based Nuclear MCA with a good geometry set up. Classification of wood and their medicinal uses also studied. Analysis of results showed an appreciable evidence of radiation attenuation, attenuation coefficient decreasing with increase of gamma en-ergy and significant variation for different species.