Radiometric characterization of zeolite minerals used in many industries and assessment of radiological risks.

Zeolites are important additives materials which are widely used in different industries such as construction, paper, paint, agriculture, textile, and fertilizer. In this study, radiometric characterization of natural zeolite samples collected from four zeolite open quarries in Western Anatolia in Turkey were determined using a gamma-ray spectrometry with high purity germanium detector. The radiological risks due to the use of zeolite samples as raw materials in cement and concrete production was assessed for adult people by estimating activity concentration index and annual effective dose due to external exposure in indoor. Also, annual effective radiation dose in outdoor and the corresponding lifetime cancer risk were estimated for quarry workers. Average activity concentrations of 226Ra, 232Th and 40K measured in seventy-seven zeolite samples were found as 85 ±â€¯4, 129 ±â€¯2 and 1030 ±â€¯24 Bq kg-1, respectively. The radon emanation factor and radon mass exhalation rate of zeolite samples varied from 1 to 9% with an average of 4% and 1.8-15.1 µBq kg-1 s-1 with an average of 7.2 ±â€¯0.3 µBq kg-1 s-1, respectively. The data were compared with criteria or limit values. The results revealed that usage of the examined zeolite samples as building raw materials would not cause any significant radiological risk.

X-ray absorption spectroscopy measurements of liquid water.

Recent studies, based on X-ray absorption spectroscopy (XAS) and X-ray Raman scattering (XRS), have shown that the hydrogen bond network in liquid water consists mainly of water molecules with only two strong hydrogen bonds. Since this result is controversial, it is important to demonstrate the reliability of the experimental data, which is the purpose of this paper. Here we compare X-ray absorption spectra of liquid water recorded with five very different techniques sensitive to the local environment of the absorbing molecule. Overall, the spectra obtained with photon detection show a very close similarity and even the observable minor differences can be understood. The comparison demonstrates that XAS and XRS can indeed be applied reliably to study the local bonding of the water molecule and thus to reveal the hydrogen bond situation in bulk water.

Performance of the YB(66) soft X-ray monochromator crystal at the wiggler beamline of the UVSOR facility.

Soft X-ray spectra have been measured using a pair of YB(66)(400) monochromator crystals at the double-crystal monochromator beamline BL7A of the UVSOR facility, where the wiggler radiation has a magnetic field of 4 T. Deformation of the YB(66) crystal due to heat load from the synchrotron radiation is almost negligible. The photon flux is about 10(8) photons s(-1) (100 mA)(-1) in the energy region 1.2-2 keV and the energy resolution is 0.7 +/- 0.1 eV around hnu = 1.5 keV. These results show that the YB(66) crystal is suitable for use as a monochromator crystal. Its application to soft X-ray spectroscopy is discussed.