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The use of lithium fluoride ͑LiF͒ crystals and films as imaging detectors for EUV and soft-x-ray radiation is discussed. The EUV or soft-x-ray radiation can generate stable color centers, emitting in the visible spectral range an intense fluorescence from the exposed areas. The high dynamic response of the material to the received dose and the atomic scale of the color centers make this detector extremely interesting for imaging at a spatial resolution which can be much smaller than the light wavelength. Experimental results of contact microscopy imaging of test meshes demonstrate a resolution of the order of 400 nm. This high spatial resolution has been obtained in a wide field of view, up to several mm 2 . Images obtained on different biological samples, as well as an investigation of a soft x-ray laser beam are presented. The behavior of the generated color centers density as a function of the deposited x-ray dose and the advantages of this new diagnostic technique for both coherent and noncoherent EUV sources, compared with CCDs detectors, photographic films, and photoresists are discussed.

The “superficiality” of the Turin Shroud body image is a characteristic frequently described in scientific papers but too often in vague terms. Originating from a discussion among the members of the Shroud Science Group†, this paper was compiled thoroughly describing the unique characteristics of the body image superficiality. This concept of superficiality is here described at the fabric, thread and fiber levels. At the fabric level, we show the importance of the geometry of the fabric. At the thread level, the very specific distribution of the color is emphasized. Finally, at the fiber level, we confirm that the color is a chemically altered layer about 200 nm thick found at the surface of the colored fibers (the inner part remains uncolored). We suggest that the chemical alteration that produced the discoloration is related to the primary cell wall of the linen fiber. The description of image superficiality here reported will be useful for the formulation of future hypotheses about the body image formation proces

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