Feasibility study of nanomaterials synthesis at MNSR research reactor through design and construction of a gamma irradiation cell

Abstract

Herein, a gamma irradiation cell consisting of a borated polyethylene (BPE) cylinder with a cadmium inner wall was designed and constructed at Isfahan miniature neutron source reactor (MNSR) for synthesis of metal nanoparticles. The cell is placed in a dry channel irradiation site near the reactor core. The performance of this irradiation cell with appropriate shape and size was evaluated and the neutron flux (φ) and the neutron and gamma dose rates (Dn and Dg) inside it were calculated using MCNP code. The results showed that the designed cell could deliver an appropriate gamma dose rate to samples and reduce the thermal neutron flux from 5.82 × 1010 to 6.28 × 107n.cm−2.s−1, i.e. over 99.89% attenuation. Also, the gamma dose rate inside the designed neutron shield is calculated to be 3.83 kSv.h−1. To evaluate the designed and constructed cell, synthesis of Pd and Ag nanoparticles (NPs) on SiO2 supporter was done. Prepared nanocomposites were characterized by using XRD, FE-SEM, and EDXA techniques. Observed results showed metallic Pd and Ag NPs were produced successfully employing a designed gamma irradiation cell at the reactor via gamma-assisted route in nanometer sizes for the first time.