222Rn concentrations of water in the Balaton Highland and in the southern part of Hungary,and the assessment of the resulting dose

In this study the ²²²Rn concentration of mains water in 120 settlements in Hungary (Southern Hungary, the Balaton Highland region) was measured. The average ²²²Rn concentration was 5.56 $(0–24.3)\mathrm{Bq}{\mathrm{l}}^{-1}$. On the basis of the ²²²Rn concentration of mains water inspected in the Southern Great Plain region, it can be stated that the ²²²Rn concentration of mains water here is, as an average, half of the ²²²Rn concentration of fountains in the same region. This decrease in radon probably happens during the water management and storage of mains drinking water. The ²²²Rn concentration of spring-water examined in the region of the Balaton Highland exceeds the average ²²²Rn concentration of drinking water (average $27.1\mathrm{Bq}{\mathrm{l}}^{-1}$).The radiation dose originating from the consumption of mains drinking water in case of adults does not reach the value of $0.1\mathrm{mSv}{\mathrm{year}}^{-1}$, even as a conservative assessment ($1\mathrm{l}{\mathrm{day}}^{-1}$ water consumption and ${10}^{-8}\mathrm{Sv}{\mathrm{Bq}}^{-1}$ dose conversion factor).     

Principal and secondary luminescence lifetime components in annealed natural quartz

Time-resolved luminescence spectra from quartz can be separated into components with distinct principal and secondary lifetimes depending on certain combinations of annealing and measurement temperature. The influence of annealing on properties of the lifetimes related to irradiation dose and temperature of measurement has been investigated in sedimentary quartz annealed at various temperatures up to $900{}^{\circ }\mathrm{C}$. Time-resolved luminescence for use in the analysis was pulse stimulated from samples at 470 nm between 20 and $200{}^{\circ }\mathrm{C}$. Luminescence lifetimes decrease with measurement temperature due to increasing thermal effect on the associated luminescence with an activation energy of thermal quenching equal to $0.68\pm 0.01\mathrm{eV}$ for the secondary lifetime but only qualitatively so for the principal lifetime component. Concerning the influence of annealing temperature, luminescence lifetimes measured at $20{}^{\circ }\mathrm{C}$ are constant at about $33\mathrm{\mu }\mathrm{s}$ for annealing temperatures up to $600{}^{\circ }\mathrm{C}$ but decrease to about $29\mathrm{\mu }\mathrm{s}$ when the annealing temperature is increased to $900{}^{\circ }\mathrm{C}$. In addition, it was found that lifetime components in samples annealed at $800{}^{\circ }\mathrm{C}$ are independent of radiation dose in the range 85–1340 Gy investigated. The dependence of lifetimes on both the annealing temperature and magnitude of radiation dose is described as being due to the increasing importance of a particular recombination centre in the luminescence emission process as a result of dynamic hole transfer between non-radiative and radiative luminescence centres.     

Luminescent, optical and color properties of natural rose quartz

Rose quartz is an interesting mineral with numerous impurities that have been studied by scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), cathodoluminescence (CL), ion beam luminescence (IBL), radioluminescence (RL), thermoluminescence (TL) and optical absorption (OA). After HF etching, rose quartz from Oliva de Plasencia (Caceres, Spain) shows under SEM the presence of other silicate phases such as dumortierite $[{\mathrm{Al}}_{6.5-7}({\mathrm{BO}}_3)({\mathrm{SiO}}_4{)}_3(\mathrm{O},\mathrm{OH}{)}_3]$. The OA spectrum of rose quartz suggests that these inclusions are the cause of coloration of rose quartz. The luminescence (CL, IBL, RL, TL) spectra behavior, at both room temperature and lower, confirms that the $\sim 340\mathrm{nm}$ emission could be associated with Si–O strain structures, including non-bridging oxygen or silicon vacancy–hole centers; the observed $\sim 400\mathrm{nm}$ emission could be associated with recombination of a hole trapped adjacent to a substitutional, charge-compensated aluminum alkali ion center; the $\sim 500\mathrm{nm}$ emission could be associated with substitutional ${\mathrm{Al}}^{3+}$ and the $\sim 700\mathrm{nm}$ peak could be associated with ${\mathrm{Fe}}^{3+}$ point defects in ${\mathrm{Si}}^{4+}$ sites. These results suggest that, while defect properties of rose quartz are not greatly dissimilar to those of purer forms of quartz and silica, further research seems necessary to determine criteria for the evolution of the newly-formed self-organized microstructures in the rose quartz lattice under irradiation.