Afterglow and thermoluminescence properties in HPHT diamond crystals under beta irradiation

Abstract

The behaviour of afterglow (AG) and thermoluminescence (TL) in nine beta-irradiated HPHT Ib type diamond crystals is presented. The transparent yellow synthetic crystals (Sumicrystal, UP-3510) were purchased from ProDiamond, Germany. Immediately after irradiation, the crystals exhibit pronounced AG (phosphorescence) caused by thermal emptying of the traps responsible for the low temperature TL peaks. All AG decay curves are well fitted with the sum of one, two or three exponential decays with the same decay lifetimes of 6.73, 12.8 and 145 s for the fast, medium and slow decay components, respectively. Two different groups of AG decay curves can be distinguished. The first group (three crystals) exhibits intense AG related to fast emptying of some shallow traps. The initial AG intensity of other crystals (second group) is 2-3 order lower than those of the first group crystals. This difference is due to the absence (or very low intensity) of the shallow traps in these crystals. TL glow curves consist of two sets of peaks. The first one with peak maxima at about 50, 70, 180 and 280 8C has high sensitivity but saturates at doses higher 1 Gy. The second set looks like several strongly overlapped TL peaks that exhibit linear-sublinear behaviour. The intensity of the TL peaks of the second set correlates with the intensity of TL below 100 8C.TL glow curves recorded immediately after beta irradiation with indicated doses; the initial part of the curves (below 30 8C) corresponds to AG at room temperature. The inset shows the dose growth of integrated TL between 30 and 330 8C.

Raman and Thermoluminescence Studies of HPHT Synthetic Nanodiamond Powders

“…The main TL properties of the HPHT diamond crystals were reported elsewhere. [10][11][12][13][14][15][16][17][18][19] Nanocrystalline diamond has received increasing attention because of its unique perspectives in biomedical applications. But up to now only few works devoted to study nanodiamond TL properties have been reported.…”

“…Another synthetic diamond is high pressure–high temperature (HPHT) diamond that is commercially available since 1950s with main application as cutting and drilling tools. The main TL properties of the HPHT diamond crystals were reported elsewhere …”

Properties of the HPHT diamond when used as a soft X-Ray detector

“…This aspect, entails that such composite materials behave in front of the radiation of a variety of ways to interact with the treated tissue, making it difficult for direct application in radiation therapy, a procedure widely used today for the treatment of cancer, if not the most common, and of special interest in the application of these devices. Recently, the synthetic diamond grown by the technique of high-pressure and high-temperature (HPHT) has been proposed as a detector of ionizing radiation Low, et al, 2011;Meléndrez, et al, 2006;Chernov, et al, 2013;Gil et al, 2014;Gil et al, 2015. The importance of this material lies in its physical and chemical properties, as it has a Zeff=6 (atomic number-cash) equivalent to the human tissue, this is a relevant feature in a dosimeter for radiation therapy.…”

Thermoluminescence studies on HPHT diamond crystals exposed to β‐irradiation

“…However, the defects created by the presence of these impurities could lead to instability of the HPHT diamond as a dosimeter. Treatments that use high‐energy radiation or thermal annealing have proven to facilitate the observation of individual impurity ions, paramagnetic defects, or to enhance the thermoluminescence (TL) efficiency in HPHT diamonds . Previously, it has been reported an improvement of ∼5% in TL reproducibility on HPHT type Ib synthetic diamond exposed to β‐radiation after a 1073 K thermal annealing process and/or high dose γ‐irradiation .…”