Investigation of Termoluminescence of alexandrite for applications in the dosimetry area

• Grant number: 18/22179-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2018
• End date: November 30, 2019
• Field of knowledge: Engineering - Mining Engineering - Mineral Prospecting
• Principal Investigator: Neilo Marcos Trindade
• Grantee: Stephanie Lins Dardengo Cavalcanti
• Host Institution: Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Alexandrite is a mineral variety of chrysoberyl with the incorporation of chromium in its lattice with the following chemical composition: BeAl2O4: Cr3+. Noteworthy, Brazil is one of the largest world producers of alexandrite; but there are few studies on the physics properties of natural alexandrite. The objective of the research is to investigate the effects of ionizing radiation beta In alexandrite using the thermoluminescence (TL) technique. Preliminary studies have shown that alexandrite exhibits three TL peaks low-intensity about 80, 130, 160 oC and two high-intensity peaks about 260 and 305 oC (1 oC/s). The results obtained so far in natural samples showed that the TL signal varied linearly with the irradiation dose and that the TL signal was stable at room temperature after exposure to irradiation, demonstrating the potential use of alexandrite in dosimetry area. The aim is to investigate the kinetic behavior of TL peaks by means of methods such as variable heating rate, glow curve best fitting using Glowfit software, TM-Tstop, and TM-dose analysis; obtaining data such as energy and frequency factor. It is believed that impurities, especially Cr3+ and Fe3+, have an important role in these characteristics. The chemical composition of the samples will be obtained by the X-ray fluorescence technique and the electronic transitions will be verified through optical absorption in the visible region. The research will be conducted in collaboration with the University of São Paulo.