Abstract: An X-ray radiation detector is thermally conductively secured to the end of a cryogenically cooled copper cold finger in an evacuated atmosphere. A collimator having a conical radiation conduit at a relatively low evacuated pressure is thermally conductively secured to the end of the cold finger for passing radiation emitted by an electron microscope and reflected from a specimen to the detector in a windowless environment. The collimator and cold finger are at about the same cryogenic temperature. The detector is maintained at a temperature of a few degrees C. above that of the collimator. The collimator conduit radiation ingress aperture is dimensioned to limit gas flow to the conduit to limit moisture flow into the conduit and to the detector, the gas flow being molecular in a low pressure atmosphere.

Abstract: Parallel heat paths are provided by three nested tubes, the outer tube being of stainless steel and connected cantilevered to a housing at ambient temperature. The innermost tube forms a cold finger having a negligible temperature gradient and secured in thermal conductive isolation concentrically within an intermediate cold sleeve tube which is also concentric within the outer tube, the cold finger and cold sleeve tubes being made of copper. The tubes have a minimum diameter and specular facing surfaces to minimize radiation coupling which is the major source of heat transfer between the tubes. The two inner tubes have minimum thermal conductive coupling via thermal insulating tapered rings at one end and a thermal insulating support at the other end. A radiation detector is secured to the inner cold finger tube for receiving X-ray radiation from a specimen in an electron microscope. The other ends of the two inner tubes ar thermally conductively connected to a heat sink Dewar via braided copper straps.

Abstract: Compositions, preferably in particulate form, comprising a cellular matrix having oil in the cells thereof in which the matrix comprises polysaccharide and polyhydroxy compounds in such proportions that the oil may constitute up to 80% by volume so stably held in the cells that the extractable oil is not substantially in excess of 5%. This is accomplished by proportioning the ingredients to produce a glassy, preferably water soluble, matrix having a plastic or flowable range that prevents or seals oil escape paths in the wall material such as cracks, fissures, pin holes and deep pits. The polysaccharides are primarily not the sweet, readily soluble saccharides like sugar but rather higher polysaccharides of the non-sweet, colloidally soluble types such as natural gums, e.g., gum arabic, starch derivatives, dextrinized and hydrolyzed starches, and the like. The polyhydroxy compounds may be alcohols, plant-type sugars, lactones, monoethers and acetals.