Abstract: An ion source device comprises a plasma generating vessel for generating plasma therein, a plurality of magnets arranged on an outer periphery of the plasma generating vessel to establish a cusp field in the plasma generating vessel, means for supplying a power to generate the plasma in the plasma generating vessel, and an anode electrode arranged on an inner wall of the plasma generating vessel and adapted to be heated by electrons emitted from the plasma and maintain the heat.

Abstract: The radioactive structure comprises a radioactive source surrounded by a housing. The housing contains a first and second shielding body and a connecting device. The first shielding body has a protrusion which contains a first recess for receiving the radioactive source. The second shielding body has a second recess in one face end which accommodates the protrusion and a conical aperture communicating with the second recess in another face end. The connecting device connects the first shielding body to the second shielding body. When the radioactive source is inserted into the first recess and when the protrusion is located in the second recess, the radioactive source emits radiation primarily through the conical aperture into the environment. The source preferably contains americium which emits gamma radiation. The structure may be used as a motion correction sensor or as a marker in nuclear diagnostic imaging.

Abstract: The invention relates to a method and device that make it possible to determine interplanar distances in electron diffraction images in electron microscopes. This is done through its beam stopper, which originally was used only to interrupt the central beam for better display of the diffraction image.The invention makes possible the elimination of errors normally committed in determining said distances, many of them related to the deformation of the film and to unsuitably exposed photographs.

Abstract: Apparatus for storing spent fuel assemblies of a nuclear reactor including a fuel-assembly transport cask having a hollow chamber for receiving therein at least one fuel assembly and having a cover for gas-tightly closing off an opening to the hollow chamber, including means for supplying a trace gas into the hollow chamber, an additional cover defining a leakage detection chamber covering the cross-section of the opening to the hollow chamber, and a measuring device for the trace gas connected to the leakage detection chamber for monitoring gas-tightness of the closure of the opening to the hollow chamber, and method for using the apparatus.