Experimental validation of in-vivo imaging condition with synchrotron-based X-ray tomography to minimize radiation dose effects on root growth in soil

• Grant number: 25/04801-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Talita Rosas Ferreira
• Grantee: Julia Fernandes Ragonha
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

The electron accelerator Sirius, in Brazil, hosts a beamline (MOGNO) dedicated to X-ray micro computed tomography (µXCT). This technique is essential to applications in biological and soil sciences, providing in-vivo three-dimensional (3D) information on the soil-plant system. However, the X-rays may cause radiation damage to live samples, depending on the exposure conditions. A previous study carried out at the MOGNO beamline has shown, by Monte Carlo simulations, that the X-ray dose rate absorbed on roots developing in soil is negligible when the photon energy is 67 keV and the soil diameter is 40 mm. Thus, this project aims to experimentally validate this condition. We propose to: a) define a reproducible methodology to grow wheat roots and determine its natural growth rate, b) acquire µXCT images over time of the roots developing in soil, considering the most favorable simulated condition, c) determine the growth rate of the roots based on the images, d) measure the experimental dose rate with luminescent passive dosimeters based on the Optically Stimulated Luminescence (OSL) technique and Radioluminescence (RL). The hypothesis of this study is that, at the most favorable simulated exposure condition to X-rays, the root growth rate remains constant over hourly µXCT image acquisition. We also expect the simulated dose values to be similar with the experimentally measured values using OSL and RL dosimeters. This work will set a precedent for other scientific cases where radiation dose is a limiting factor.