Study of mechanisms of luminescence in alexandrite pellets using Optically Stimulated Luminescence

• Grant number: 22/14516-8
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Effective date (Start): March 01, 2023
• Effective date (End): May 31, 2023
• Field of knowledge: Engineering - Nuclear Engineering - Applications of Radioisotopes
• Principal Investigator: Neilo Marcos Trindade
• Grantee: Matheus Cavalcanti dos Santos Nunes
• Supervisor: Makaiko Liwiro Chithambo
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: Rhodes University, South Africa
• Associated to the scholarship: 21/12758-1 - Development and characterization of an optically stimulated luminescent detector based on natural Brazilian alexandrite, BP.MS

Abstract

Optically stimulated luminescence (OSL) is the light emitted from the recombination of charges optically released from specific traps inside of a material previously irradiated with ionizing radiation. Because of this, OSL is an important solid-stated dosimetric technique used for the determination of environmental radiation dose absorbed by materials. Recently we have studied some luminescent properties of alexandrite Brazilian mineral (BeAl2O4:Cr3+) using the OSL technique. We have concluded that in this material, in a composite with an organic matrix, the OSL signal presents a linear increase with an absorbed dose of beta radiation. Within this context, the potential of natural alexandrite as a dosimeter has also been investigated. However, at this moment, more in-depth investigations are proposed for the study of defects in alexandrite, such as studying the theoretical models involved and applying instrumentation varied of the OSL techniques (continuous optical stimulation, linearly-modulated optical stimulation, and time-resolved optical stimulation techniques). Therefore, the objective of this project is to carry out the theoretical analysis and the deconvolution of the OSL curves for the development of models that fit the OSL results obtained for alexandrite. The work will be supported by the Luminescent research group at Rhodes University, South Africa, which has expertise in OSL from minerals.