摘要:
The invention relates to a method and apparatus for providing cooling in a reloadable cooling apparatus, which can be used in actuators requiring low temperatures. According to the invention, the loading of at least one cooling element (2, 22, 32), located in the vacuum of the cooling apparatus, is carried out through at least one cooling surface (4, 25, 34), connected to outside the cooling apparatus (1, 21, 31), and the period between two loadings is extended by reducing the transversal area of the supporting member (3, 23, 33) and by reducing the heat conduction distance of the supporting member (3, 23, 33) of the cooling element from the cooling apparatus (1, 21, 33), advantageously by shaping the supporting member (3, 23, 33).
摘要:
The invention relates to detection performed over millimeter and submillimeter wavelengths, especially to imaging solutions functioning over a submillimeter-wavelength range. The system of the invention uses detectors, comprising antenna coupled bolometers together with wavelength selective optics. The detector matrix is preferably curved for reducing the number of imaging errors. In order to provide a curved detector matrix, the detector matrix is constituted by flat submatrices, each being provided with one or more integrated antenna coupled bolometers. The detectable frequency range is preferably limited in two stages, first by means of wavelength selective optics and secondly by means of the operating band of the antenna of an antenna coupled bolometer. In order to focus the incoming radiation on bolometers, the bolometer substrate is fitted or the surface or interior of the bolometer substrate is provided with a bolometer lens or a corresponding optical element in alignment with each bolometer.
摘要:
The invention relates to X-ray fluorescence measuring systems, more specifically to methods for producing polarized X-radiation. The invention is based on the idea of using beryllium as the anode material despite its poor effectiveness. Some of the X-radiation spectrum produced by a beryllium anode is polarized radiation, more specifically its high-energy portion. The system of the invention involves filtering out the low-energy portion of the spectrum, whereby the remaining intensely polarized radiation can be used as excitation radiation in X-ray fluorescence measurements. The system of the invention is capable of achieving a certain intensity of polarized X-radiation by means of an X-ray tube less powerful than those used in common prior art solutions based on the use of scattering media.
摘要:
A radiation window foil is provided for an X-ray radiation window. It includes a continuous window layer with a first side and a second side. A first mesh or grid layer is stacked on or bonded to the first side of the continuous window layer. A second mesh or grid layer is stacked on or bonded to the second side of the continuous window layer.
摘要:
The invention relates to a method for preventing leaks in a propeller shaft bearing arrangement including a plain bearing (2), which is lubricated with oil or water and which supports the propeller shaft (1) extending through an opening in the body (4) of a hull, and packing members (6,7) for keeping the lubricant in the lubrication space and for preventing water from entering the bearing arrangement. The pressure vibrations occuring in the lubricant are equalized by arranging, in the lubrication space, a medium prossesing a high compressiblility, which medium through changes in volume receives and equalizes said pressure vibrations.
摘要:
The invention relates to a gas drift detector (100) comprising: a chamber formed by: a housing (102) having a first end and a second end; a radiation window (104) arranged to cover an opening of the first end of the housing (102); and a substrate (106) arranged to cover an opening of the second end of the housing (102), an anode (110) arranged to the substrate (106), one or more conductive rings (108) arranged on a surface (106a) of the substrate facing inside the chamber, and an amplifier (112) arranged to the opposite surface (106b) of the substrate than the conductive rings (108). The amplifier (112) is electrically connected to the anode (110). The chamber is filled with a gas.
摘要:
A radiation window foil is provided for an X-ray radiation window. It includes a continuous window layer with a first side and a second side. A first mesh or grid layer is stacked on or bonded to the first side of the continuous window layer. A second mesh or grid layer is stacked on or bonded to the second side of the continuous window layer.
摘要:
A measurement apparatus and method are provided for determining the material composition of a sample. An X-ray fluorescence detector (412) detects fluorescent X-rays coming from said sample under irradiation with incident X-rays. A laser source (301) is adapted to produce a laser beam. Focusing optics (302) focus said laser beam into a focal spot on a surface of said sample. An optical sensor (312) detects optical emissions coming from particles of said sample upon being exposed to said laser beam at said focal spot. A gas administration subsystem (104, 105, 106, 107, 108) is adapted to controllably deliver gas to a space (101) around said focal spot.
摘要:
A drift detector produces an indication of an occurred hit of a quantum in the detector element. For neutralising accumulated charge in the detector element, indications of occurred hits are used to trigger pulses of deliberately increased neutralisation current into the drift detector for the duration of a limited time interval. Alternatively such triggering may be based on the operation of a timer.
摘要:
Disclosed is a method and an apparatus for analyzing pieces of ore for the purpose of sorting. Each piece falling by the analyzer is irradiated individually by means of two gamma radiation sources operating at different energy levels so selected that, as to the scattering effect, at one level the Compton effect is predominant and at the other level the Compton effect and the photoelectric effect compete with each other. The former effect is strongly dependent on the ordinal number of the element and, thus, by detecting with at least one detector the scattering intensities produced with the said two sources of radiation and comparing the scattering intensities with each other, the proportion of heavy elements in the ore piece can be determined and the ore piece can be classified on the basis thereof. For example, one energy dispersively operating scintillation detector can be used for detecting the scattered radiation.