Identification of ESR centers and their role in the TL of natural salt from Lluta, Peru

Darwin J Callo-Escobar; Nilo F Cano; T K Gundu Rao; Carlos D Gonzales-Lorenzo; Klinton V Turpo-Huahuasoncco; Yolanda Pacompia; Monise B Gomes; Jose F Benavente; Jose F D Chubaci; Shigueo Watanabe; Jorge S Ayala-Arenas

doi:10.1016/j.apradiso.2022.110126

Identification of ESR centers and their role in the TL of natural salt from Lluta, Peru

Appl Radiat Isot. 2022 Apr:182:110126. doi: 10.1016/j.apradiso.2022.110126. Epub 2022 Jan 25.

Affiliations

¹ Escuela Profesional de Física, Facultad de Ciencias Naturales y Formales, Universidad Nacional de San Agustín de Arequipa (UNSA), Av. Independencia S/N, Arequipa, Peru. Electronic address: dcallo@unsa.edu.pe.
² Instituto do Mar, Universidade Federal de São Paulo, Rua. Doutor Carvalho de Mendonça, 144, CEP, 11070-100, Santos, SP, Brazil. Electronic address: nilocano@if.usp.br.
³ Escuela Profesional de Física, Facultad de Ciencias Naturales y Formales, Universidad Nacional de San Agustín de Arequipa (UNSA), Av. Independencia S/N, Arequipa, Peru.
⁴ Instituto de Física, Universidade de São Paulo, Rua do Matão, Travessa R, 187, CEP, 05508-090, São Paulo, SP, Brazil.
⁵ CIEMAT, Av. Complutense 40, E, 28040, Madrid, Spain.

PMID: 35114478
DOI: 10.1016/j.apradiso.2022.110126

Abstract

In this study, the thermoluminescence (TL) properties of natural NaCl from Lluta, Arequipa-Peru was investigated. The number of peaks and the kinetic parameters associated with the TL glow peaks of NaCl sample after gamma-irradiation were analyzed by initial rise and deconvolution method. Defect centers induced in pure salt by gamma irradiation have been studied by electron spin resonance (ESR) with a view to identify the centers associated with the TL process in the salt. Thermal annealing experiments indicate the presence of three defect centers. Center I characterized by the g-value 2.011 is identified as an O^- ion and relates with the dominant TL peak at 220 °C. Center II with a g-value of 2.0058 is attributed to a F center and is found to correlate with the 128 °C TL peak. Center III has of g-value 2.014 and is also assigned to an O^- ion.

Keywords: Defects centers; ESR; NaCl; Radiation effects; TL.