Nitrogen-doped diamond: Thermoluminescence and dosimetric applications

Diamond exhibits outstanding properties that make it a material of interest for radiation detection and thermoluminescence and particularly in the field of dosimetry applications. The emergence of synthetic samples from the chemical vapour deposition (CVD) technique offers new possibilities to fabricate cheap and reproducible devices, and if the same reliability on the thermoluminescence (TL) properties would be attained, several applications towards radiotherapy are foreseen. To date however, the poor reproducibility and limited linearity of the TL signal with the dose in non-doped CVD diamonds requires particular improvements. The main purpose of this present study is to focus on the control of the trapping level populations in CVD diamond from the deliberate incorporation of nitrogen impurities during the film growth. Several samples were elaborated using the MWCVD technique while varying the nitrogen incorporation from 4 to 40 ppm in the gas mixture. The effective incorporation of nitrogen in the films was appreciated using Raman spectroscopy. The aim of the current communication is to report on the effects of nitrogen incorporation in the films and its effect on the TL signal response towards the improvement of the TL dosimetric applications. The results suggest that optimised dosimetric properties could be obtained with incorporation of low and precisely controlled nitrogen concentrations. (c) 2006 Elsevier B.V. All rights reserved.