Silicate glass-based nanocomposite scintillators for Gamma-ray spectroscopy

• Grant number: 14/12627-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2014
• End date: October 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Andrea Simone Stucchi de Camargo Alvarez Bernardez
• Grantee: Lakshmi Narayana Gandham
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass, AP.CEPID

Abstract

Since the past century scientific community has witnessed the discovery of many new inorganic scintillator materials and numerous advances in our understanding of the basic physical processes governing the transformation of ionizing radiation into scintillation light. Scintillation material can be gaseous, liquid, glass-like, organic (plastics), or inorganic. In each case the material should be transparent to its own scintillation light and consist of an emission center and a host lattice. Inorganic scintillators are widely applied for gamma-ray detection. Detector selection occurs on the basis of requirements concerning efficiency, energy and time resolution, dead time, position resolution, the possibility to synthesize relatively larger size materials, materials quality (radiation hardness, mechanical properties, etc.) and cost. In a number of cases energy resolution is very important. Gamma rays interact with a scintillator by means of 1) photoelectric interaction (dominant below 500 keV), 2) Compton scattering (dominant around 1 MeV), or 3) pair creation (dominant well above the threshold at 1.02 MeV). In this proposed research work we are planning to synthesize high-quality silicate based glass ceramics containing LSO or YSO or GSO: Ce3+ nanocrystals using sol-gel process for scintillation applications, especially for Gamma ray detection with relatively high energy resolution. The successfully synthesized silica nano-glass ceramics will be characterized systematically for their structural (XRD, SEM-EDAX), chemical (FTIR, RAMAN), thermal (TG/DTA/DSC), spectroscopic (Optical absorption, PLE, PL, RL), light scattering, decay lifetime measurements, and scintillation properties analysis. The synthesized transparent silica glass ceramic scintillators containing a ~50-60% volume fraction of <10 nm diameter LSO or YSO or GSO: Ce3+ nanocrystals optical properties will be compared with bulk LSO or YSO or GSO: Ce3+ crystals and other scintillators in order to assess the merit of our sol-gel approach and to identify potential paths for commercialization. In this work, since our synthesized scintillation glass ceramics contained gadolinium (Gd) which has high Z-number and could be used to efficiently detect gamma rays or x-rays in many applications such as computerized tomography (CT), positron emission tomography (PET), single photon emission computed tomography (SPECT) and homeland security.