Clay particles - potential of positron annihilation lifetime spectroscopy (PALS) for studying interlayer spacing
نویسندگان
چکیده
منابع مشابه
Single shot positron annihilation lifetime spectroscopy
Recent developments in positron trapping technology have made possible experimentation with dense interacting positronium gases. Along with these capabilities comes a need for suitable measurement techniques, and accordingly we have developed a method to measure positronium lifetimes from a single intense burst of positrons. Our method is based on recording the anode signal from a photomultipli...
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In this study, a positron annihilation lifetime spectrometer was set up and its resolution was optimized. The spectrometer is a fast-slow arrangement with time resolution of 250 ps. To obtain lifetime components and their intensities from analyzing positron annihilation lifetime spectrum, the Pascual software is used. Positrons are from a source of radioactive 22NaCl with 20 μCi activity enclos...
متن کاملA fast detector for single-shot positron annihilation lifetime spectroscopy
When an intense sub-nanosecond positron pulse impinges upon a target, a pulse of g-rays is created which can yield information concerning electron–positron pairs just prior to annihilation. Many conventional g-ray detectors are unable to exploit the timing information contained within such pulses, and we describe here the development of a fast detector that is able to do so. Using a singlecryst...
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The effects of freeze/thaw (F/T) cycling on the structure of dry Nafion® membranes were investigated using positron annihilation lifetime spectroscopy (PALS). The method correlates the lifetime and relative intensity of positrons (anti-electrons) annihilating in the open-volume voids of the membrane with void size and void volume fraction. The results, though still preliminary, show freeze/thaw...
متن کاملInvestigation of the Degree of Disorder of the Structure of Polymer Soft Contact Lenses Using Positron Annihilation Lifetime Spectroscopy PALS.
BACKGROUND Hydrogel and silicone-hydrogel polymeric materials are widely used in ophthalmology for the manufacture of contact lenses. An important aspect is the investigation of the structure of these materials. OBJECTIVES This study has been conducted in order to compare the degree of disorder and presence of free volumes in the internal structure of the polymeric soft contact lenses Omafilc...
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ژورنال
عنوان ژورنال: Journal of Physics: Conference Series
سال: 2011
ISSN: 1742-6596
DOI: 10.1088/1742-6596/262/1/012022