Nondestructive method for quantifying thallium dopant concentrations in CsI:Tl crystals

Area of Science:

• Materials Science
• Analytical Chemistry
• Nuclear Instrumentation

Background:

• Cesium iodide doped with thallium (CsI:Tl) is a widely used scintillator material.
• Accurate quantification of thallium (Tl) dopant concentration is critical for optimizing CsI:Tl scintillator performance.
• Existing methods for dopant analysis may be destructive or lack precision.

Purpose of the Study:

• To establish a non-destructive quantitative method for measuring Tl content in CsI:Tl scintillators.
• To investigate the influence of crystal size and growth parameters on Tl concentration.
• To demonstrate the broader applicability of the developed method to other scintillator activator ions.

Main Methods:

• Utilized a handheld X-ray fluorescence (XRF) instrument (LeadTracer™).
• Developed a quantitative measurement technique for Tl in CsI:Tl samples.
• Analyzed variations in Tl concentration based on crystal dimensions and fabrication parameters.

Main Results:

• Successfully implemented a non-destructive XRF method for accurate Tl quantification in CsI:Tl.
• Observed correlations between crystal size, growth conditions, and Tl dopant levels.
• Validated the method's potential for analyzing other activator ions like Ce(3+) and Eu(2+).

Conclusions:

• The developed XRF technique provides a reliable and non-destructive means to measure Tl content in CsI:Tl scintillators.
• Understanding the impact of crystal parameters on dopant concentration is essential for scintillator material development.
• This versatile XRF approach can be extended to quantify other critical dopants in various scintillator materials.