Abstract:
A semiconductor wafer is exposed with a pattern from a mask or reticle in an exposure tool. The exposure tool has an adjustable lens system and a light source, which is tunable in wavelength. A first exposure is performed with a tuned first wavelength and a first setting of the lenses. Prior to performing a second exposure onto the same wafer and into the same resist layer, the wavelength of the light source is varied to a second wavelength in order to mimic a focus offset. A resulting image shift at the slit edges of the scanning system due to chromatic aberration is then corrected for by setting the lens system in dependence of the difference between the tuned first and second wavelength. Having tuned second wavelength of the light source and having set the lens system, the second exposure is performed. A continuous adjustment of the lens system based upon a continuously varying light source wavelength can be accomplished.
Abstract:
A phosphor for a high energy radiation detector is formed by a rare earth oxisulfide having the general sum formula (M.sub.1-x Ln.sub.x).sub.2 O.sub.2 S, wherein M is at least one element of the group Y, La and Gd, Ln stands for at least one element of the group Eu, Ce, Pr, Tb, Yb, Dy, Sm and Ho, and whereby (2.times.10.sup.-1).gtoreq..times..gtoreq.(1.times.10.sup.-6), which also contains molybdenum in a proportion between 10.sup.-1 and 10.sup.-6 mol percent for reducing the afterglow of the phosphor.
Abstract:
A synchrotron radiation source includes a beam guidance system for accelerating and storing an electron or positron particle beam on a closed trajectory. In order to generate the synchrotron radiation, the beam guidance system has at least one approximately achromatic mirror magnet being formed of superconducting winding configurations and in which the trajectory is bent through approximately 270.degree.. Further components of the beam guidance system, such as deflecting magnets and focusing magnets do not necessarily need to be constructed from superconducting components. The synchrotron radiation source permits the utilization of all of the advantages of superconductors with the most extensive avoidance of the disadvantages associated therewith, since the application of superconducting components can be restricted to the components specifically constructed for the generation of the synchrotron radiation.
Abstract:
A magnetic thin-film head with layer-wise build-up on a nonmagnetic substrate for a recording medium which can be magnetized vertically, comprises a ring head-like conduction body for carrying magnetic flux having two magnet legs, of which the end pole pieces facing the recording medium have, respectively, a predetermined small width transverse to the direction of motion and change into widening leg parts a space being provided between the two magnet legs through which the turns of a write/read coil winding extend. A magnetic head having highly efficient write and read functions is thereby obtained. The vertical length (gap height h) of one of the two end pole pieces is relatively small, while the corresponding length (l) of the other end pole piece is several times the former, and a widening leg part of the magnet leg with the comparatively shorter vertical end pole piece is provided with a recess which extends along its center line lying in the conduction direction of the magnetic flux and extends at least approximately to the shorter end pole piece.
Abstract:
A method for manufacturing a disc-shaped curved magnet coil, particularly for a system for accelerating and/or storing electrically charged particles such as electrons. The conductors of the coil to be made are to be arranged around a winding core having a convex outside and a concave inside and are then to be fixed in position around the winding core. A coil form or fitting piece of predetermined shape is first added to a winding core, so that a provisional winding body with only positive radii of curvature on its outsides is formed. The conductors are wound under tension around the winding body and subsequently are fastened only to the winding core of the winding body and, after the coil form is removed, the thus exposed conductor portions facing the region of the concave inside of the winding core are pressed against this inside and fixed in position.
Abstract:
A directly converting radiation detector with a diode structure having first and second operating electrodes on opposite sides of a semiconductor body has an additional injector electrode, which injects charge carriers for the compensating charged traps in the semiconductor body. The secondary dark current generated in this way does not flow via the electrode used for measurement purposes and therefore does not influence the measured signal. The injection is facilitated by suitable doping under the injector electrode.
Abstract:
An x-ray detector element suitable for use in computer tomography has a semi-insulating semiconductor body composed of a compound semiconductor, and is operated with a constant voltage source so that it functions as an x-ray-sensitive photoconductor. A measurement instrument is connected across the voltage source for detecting the photocurrent, which is indicative of the x-rays incident on the semiconductor body.
Abstract:
A magnetic field apparatus for a particle accelerator having a particle track having curved sections contains several magnetic field-generating windings, and at least one supplemental winding provided for focusing the electrically charged particles. The system does not require pre-accelerators and relatively large particle streams should be capable of being accelerated nevertheless to relatively high energy levels. In the region of at least one of the curved sections of the particle track, an azimuthal guiding field for the particles is generated by the supplemental winding during the acceleration phase. This supplemental winding is designed as an appropriately curved electric conductor arrangement which in part encloses the particle track and which is designed in the manner of a hollow channel open toward the outside. The conductor arrangement is appropriately structured for suppressing eddy currents and carries a current transversely to the particle track.