Fractional Free Volume Dependence of Neutron-IrradiatedPolystyrene (PS) Measured by Positron Method. Iraqi Journal of Science [Internet]. 2025 Jan. 14 [cited 2025 Jan. 19];48(1):109-12. Available from: https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/14610