Soft X-ray microscopy has been developed for high resolution imaging of hydrated biological specimens due to the availability of water window region. In particular, a projection type microscope has advantages in wide viewing area, easy zooming function and easy extensibility to CT. The blur of projection image due to the diffraction of X-rays, which eventually reduces spatial resolution, could be corrected by an iteration procedure, i.e., repetition of Fresnel and inverse Fresnel transformations. However, it was found that the correction is not sufficiently effective for all images, especially for images with low contrast. In this study, first, grayscale distribution of the projection images was analyzed to reveal the reason for the insufficient correction. The result showed that the insufficient correction is due to high background noises. Therefore, a noise removal method prior to the iteration procedure was applied and found to be effective. Thus, some chromosome images with magnification of 329 times or lower which had not been correctable solely by the iteration procedure became successfully correctable after noise removal in combination with our contrast enhancement method whose effect was evaluated as effective in the previous study.
For the estimation of radioactive inventory, the radioactive waste drums should be classified based on their radioactive composition. We compared the classification performances between random forests and support vector machine, both of which are machine learning methods. The tested uranium in waste drums included natural uranium from uranium ore, reprocessed uranium from nuclear fuel, and natural uranium with rich radium from the impurities in yellow cake. A total of 75 data in 1037 γ-ray spectral data of these drums were trained, and 962 data were applied in the classification models. It was found that the random forests were advantageous in the shift of the channels.
There are four muon facilities in the world. They are: Rutherford-Appleton Laboratory (RAL) in the UK, Paul Scherrer Institut (PSI) in Switzerland, TRIUMF in Canada and J-PARC Muon Facility in Japan. This article is going to report characters, advantages and how to effectively use those muon facilities.