Abstract: An x-ray generating system includes a source of x-ray radiation, a waveguide bundle optic for collimating the x-ray radiation produced by the source, a focusing optic for focusing the collimated x-ray radiation to a focal point.

Abstract: Disclosed is an X-ray reflecting device and an X-ray reflecting element constituting the X-ray reflecting device capable of facilitating a reduction in weight and being prepared in a relatively simple manner. The X-ray reflecting element of the present invention comprises a body made of a solid silicon, and a plurality of slits formed in the body in such a manner as to penetrate from a front surface to a back surface of the body. Each of the slits has a wall surface serving as an X-ray reflecting surface.

Abstract: In the present invention we propose a new device for x-ray optics which is an analogy to the zone plates but working for higher x-ray energies. This is achieved by using both refraction and diffraction of the x-rays and building the new device(s) in a three dimensional structure, contrary to the zone plates which are basically a two dimensional device. The three dimensional structure is built from a multitude of prisms, utilizing both refraction and diffraction of incoming x-rays to shape the overall x-ray flux. The result will be the first ever device achieving true two dimensional focusing in the x-ray energy range usually employed in medical imaging and may be used in a wide area of applications in this field and in other fields of x-ray imaging. The device will further be fairly straight forward to produce in large volumes.

Abstract: An X-ray shielding apparatus (40) and an X-ray device incorporating such an apparatus are described. The apparatus (40) comprises a stationary member (94) having an aperture and one or more shielding members (96, 98) movable in relation to the stationary member (94) and made from an X-ray shielding material. The one or more shielding members (96, 98) define an X-ray passage (90) within the aperture that is smaller than the aperture. Movement of the one or more shielding members (96, 98) is restricted such that the one or more shielding members (96, 98) in each position relative to the stationary member (94) cover the aperture at least in an area outside the X-ray passage (90).

Abstract: Systems and methods for automatically determining a beam parameter at each of a plurality of treatment nodes are disclosed. The beam parameter may include a beam shape, beam size and/or beam orientation. Systems and methods for automatically selecting multiple collimators in a radiation treatment system are also disclosed.

Abstract: An apparatus for recording an image on a sheet comprises a linear array of light sources and an optical element for transmitting light emitted from the light sources. The optical element comprises a light-transmissive member, having an entry surface for disposal near the light sources. The entry surface defines at least one set of prisms. The optical element can further define a DCPC (dielectric compound parabolic concentrator) in cross-section. Collection optics, such as a SELFOC® lens, receives light reflected from the sheet. Each prism of the optical element defines an angle whereby light exiting the optical element is outside the acceptance angle of the collection optics.

Abstract: An illumination system is used to illuminate a specified illumination field of an object surface with EUV radiation. The illumination system has an EUV source and a collector to concentrate the EUV radiation in the direction of an optical axis. A first optical element is provided to generate secondary light sources, and a second optical element is provided at the location of these secondary light sources, the second optical element being part of an optical device which includes further optical elements, and which images the first optical element into an image plane into the illumination field. Between the collector and the illumination field, a maximum of five reflecting optical elements are arranged. These optical elements reflect the main beam either grazingly or steeply. The optical axis, projected onto an illumination main plane, is deflected by more than 30° between a source axis portion and a field axis portion.

Abstract: A device for improving resolution capability of an x-ray optical apparatus for an x-ray incident from a direction of incidence includes a mirror element including a mirror edge formed as a cylindrical shell section around an edge axis. The mirror element is spaced apart, in a radial direction, from a focal axis that is parallel to the direction of incidence. The edge axis is oriented at a first non-zero angle relative to the focal axis when viewed along a radial axis. The edge axis is oriented at a second non-zero angle relative to the focal axis.

Abstract: In order to detect an image generated by an image source, a mirror arrangement is arranged between the image source and a detector. The mirror arrangement includes two spaced-apart deflection mirrors, which are parallel to each other or form an acute angle of less than 90° between them. In particular when the image source is a scintillator layer, shielding of X-rays from the detector with simultaneous compact dimensioning of the apparatus is achieved in this manner.

Abstract: In order to detect an image generated by an image source, a mirror arrangement is arranged between the image source and a detector. The mirror arrangement includes two spaced-apart deflection mirrors, which are parallel to each other or form an acute angle of less than 90° between them. In particular when the image source is a scintillator layer, shielding of X-rays from the detector with simultaneous compact dimensioning of the apparatus is achieved in this manner.

Abstract: A beam admission unit is disclosed. In at least one embodiment, the beam admission unit includes a plurality of admission segments having at least one admission slit for admitting radiation emanating from a radiation source onto a predetermined admission region. So as to implement a particularly space-saving, robust and reliable design, in at least one embodiment the admission segments are interconnected in an articulated fashion to form an admission plate chain which can be rolled up.

Abstract: Multi-layer mirror for radiation with a wavelength in the wavelength range between 0.1 nm and 30 nm, comprising a stack of thin films substantially comprising scattering particles which scatter the radiation, which thin films are separated by separating layers with a thickness in the order of magnitude of the wavelength of the radiation, which separating layers substantially comprise non-scattering particles which do not scatter the radiation, wherein the separating layers are covered on at least one side in each case by an intermediate layer of a material which can be mixed with the material of the thin films and the material of the separating layers.

Abstract: An X-ray CT system is disclosed for producing tomographic phase contrast and absorption images. In at least one embodiment, the system includes a gantry, including a stationary stator and a first rotor supported on the stator and rotates relative to the stator about a system axis, at least one X-ray source detector system that can rotate about a patient and a system axis and is arranged on the first rotor, and at least one set of X-ray optical gratings for determining phase contrast. According to at least one embodiment, the at least one set of X-ray optical gratings is arranged such that it can be displaced relative to the first rotor of the gantry.

Abstract: A system in one embodiment includes a source for directing a beam of radiation at a sample; a multilayer mirror having a face oriented at an angle of less than 90 degrees from an axis of the beam from the source, the mirror reflecting at least a portion of the radiation after the beam encounters a sample; and a pixellated detector for detecting radiation reflected by the mirror. A method in a further embodiment includes directing a beam of radiation at a sample; reflecting at least some of the radiation diffracted by the sample; not reflecting at least a majority of the radiation that is not diffracted by the sample; and detecting at least some of the reflected radiation. A method in yet another embodiment includes directing a beam of radiation at a sample; reflecting at least some of the radiation diffracted by the sample using a multilayer mirror; and detecting at least some of the reflected radiation.

Abstract: An automated X-ray imaging system and method for producing a plurality of X-ray imaging signals having selectively enhanced volumetric image resolutions, e.g., for magnifying the field of view and providing a volumetric display image having features not otherwise visible to an unaided human eye. Successive doses of X-ray radiation are applied to a portion of the subject to produce corresponding volumetric image signals. Such doses of X-ray radiation are controlled by controlling X-ray radiation characteristics, such as intensity, focal spot size, focal spot location, focal spot shape, or collimation, to cause a subsequent volumetric image signal to differ from a prior volumetric image signal in one or more volumetric image characteristics, such as volumetric image resolution.

Abstract: A focus/detector system of an X-ray apparatus is disclosed for generating projective or tomographic phase contrast recordings. In at least one embodiment, the system includes a beam source, including a focus and a focus-side source grating, arranged in the beam path to generate a field of ray-wise coherent X-rays; and a grating/detector arrangement having a phase grating with grating lines arranged parallel to the source grating for generating an interference pattern and a detector having a multiplicity of detector elements arranged flat for measuring the radiation intensity behind the phase grating. Further, the detector elements are formed by a multiplicity of elongate detection strips, which are aligned parallel to the grating lines of the phase grating.

Abstract: An X-ray examination apparatus changes a position of each X-ray sensor by rotating a sensor base, and resets a starting position of X-ray emission that becomes a X-ray focal position so that the X-ray enters each X-ray sensor after the position thereof is changed. A scanning X-ray source deflects an electron beam to easily change the position where the electron beam impinges a target of the X-ray source to an arbitrary location. The irradiating position of the electron beam then can be easily moved according to an accumulated irradiation time on the target. Therefore, maintenance can be performed without interrupting the X-ray examination.

Abstract: Linear scanning x-ray apparatus generates a collimated fan beam which is moved together with a detector relative to a subject to generate a composite x-ray image of the subject. An adjustable collimator varies the width of the imaging beam in the scan direction. A control system responds to adjustment of the collimator to combine output signals of groups of two or more pixels in the detector, in order to optimize the contrast resolution of the image signals for a given spatial resolution. The invention provides a collimator for use in the apparatus.

Abstract: X-ray device for producing X-ray images is provided. The X-ray device includes a radiation generator unit embodied for the purpose of generating an X-ray field and an image receiver that has a larger receiving area compared to the area of the X-ray field that is to be generated or has been generated, wherein the radiation generator unit and the receiving area of the image receiver are embodied to be movable relative to one another.

Abstract: In an X-ray diffraction method using the parallel beam method, an X-ray parallel beam is incident on a sample, and diffracted X-rays from the sample are reflected at a mirror and thereafter detected by an X-ray detector. The reflective surface of the mirror has a shape of an equiangular spiral that has a center located on the surface of the sample. A crystal lattice plane that causes reflection is parallel to the reflective surface at any point on the reflective surface. The X-ray detector is one-dimensional position sensitive in a plane parallel to the diffraction plane. A relative positional relationship between the mirror and the X-ray detector is determined so that reflected X-rays from different points on the reflective surface of the mirror reach different points on the X-ray detector respectively. This X-ray diffraction method is superior in angular resolution, and is small in X-ray intensity reduction, and is simple in structure.

Abstract: A system and method are provided for a high resolution radiation treatment system which provide for projecting a field of radiation energy at targeted patient tissue. The system uses a multi-leaf collimator, which is positioned such that a significant clearance is provided between the multi-leaf collimator and the isocenter plane where the targeted tissue is located. The leaves of the multi-leaf collimator are designed to provide for high step resolution in the projected radiation energy shape. Additionally, an embodiment of the system and method herein can provide for a high step resolution in the projected radiation energy shape, and for a dose calculation matrix which has matrix units which coincide with the high step resolution in the projected radiation shape.

Abstract: A sample which includes a region exhibiting a large density change, such as, bones or lungs and a region exhibiting a small density change, such as, biological soft tissues, and whose measurement is difficult to do for conventional absorption and phase contrast X-ray imaging apparatuses is highly sensitively imaged and observed. In a phase contrast X-ray imaging apparatus using an X-ray interferometer, a reference object whose shape and internal density distribution are analogous to those of a sample and which is known is positioned on an optical path other than an optical path in the interferometer on which the sample is positioned.

Abstract: A focus/detector system of an X-ray apparatus and a method for generating projective or tomographic phase contrast recordings, are disclosed. In an embodiment of the system, the system includes a beam source equipped with a focus and a focus-side source grating, arranged in the beam path and generates a field of ray-wise coherent X-rays, a grating/detector arrangement having a phase grating and grating lines arranged parallel to the source grating for generating an interference pattern, and a detector having a multiplicity of detector elements arranged flat for measuring the position-dependent radiation intensity behind the phase grating. Finally, the detector elements are formed by a multiplicity of elongate scintillation strips, which are aligned parallel to the grating lines of the phase grating and have a small period, whose integer multiple corresponds to the average large period of the interference pattern which is formed by the phase grating.

Abstract: The present invention is intended to provide a collimator control method that does not cause blades to get stuck. In a homing phase, blades are positioned based on a blade sense signal sent from a sensor. If the sensor has not sensed the blades but the rotational velocity of a motor has decreased to fall below a predetermined velocity, control states are switched. In a working phase, when an overshoot made by the blades returning to zero positions exceeds a predetermined limit, the control states are switched. Moreover, the rotating direction of the motor is reversed in order to withdraw the blades. Moreover, a collimator is reset to the control state based on tentative zero positions or the control state based on the sense signal sent from the sensor according to whether the sensor has failed.

Abstract: A focus-detector arrangement includes a radiation source with a focus, arranged on a first side of the subject, for generating a fan-shaped or conical beam of rays; at least one X-ray optical grating arranged in the beam path, with at least one phase grating arranged on the opposite second side of the subject in the beam path generating an interference pattern of the X-radiation preferably, in a particular energy range; and an analysis-detector system which detects at least the interference pattern generated by the phase grating in respect of its phase shift with position resolution. According to at least one embodiment of the invention, at least one X-ray optical grating including bars which are free from overhangs form shadows in the beam path of the fan-shaped or conical beam of rays.

Abstract: A system is in a standby mode as an imaging preparation condition in step S1. If gripping of an operation handle is detected in step S2, the operation goes to step S3, in which an electromagnetic brake is released, thereby allowing a radiation detector to be rotated substantially around the center of an imaging region. If a rotation angle is detected in step S5, a first limiting device covering an effective imaging region of the radiation detector is changed to a second limiting device so as to be constantly arranged within the effective imaging region even during rotation of the radiation detector.

Abstract: Method and apparatus for varying the hole length of a parallel hole collimator, provides a variably configurable compound collimator for use in nuclear imaging. The collimator has a plurality of substantially parallel oriented collimator cores configured for transition between a contracted configuration and an expanded configuration, wherein a gap space between said collimator cores is greater in the expanded configuration than the contracted configuration. The maximum gap space is designed to prevent photons from one hole in the collimator from reaching the detector proximate an adjacent hole of the collimator.

Abstract: An X-ray lens assembly, a device including the X-ray lens assembly and a method of manufacturing the X-ray lens assembly are described. The X-ray assembly comprises a tube member (50) including an inlet opening (90) for X-rays and an outlet opening (94) for X-rays. Additionally, the assembly comprises a capillary X-ray lens (28) mounted inside the tube member (50). The X-ray lens (28) may be mounted inside the tube member (50) by a stabilizing agent and/or by one or more separate mounting structures (96A, 96B).

Abstract: A focus-detector arrangement of an X-ray apparatus is disclosed for generating projective or tomographic phase contrast recordings of an observed region of a subject. In at least one embodiment, the arrangement includes a radiation source which emits a coherent or quasi-coherent X-radiation and irradiates the subject, a phase grating which is arranged behind the subject in the beam path of the radiation source and generates an interference pattern of the X-radiation in a predetermined energy range, and an analysis-detector system which detects at least the interference pattern generated by the phase grating in respect of its phase shift with position resolution. Further, the beam path of the X-radiation used diverges in at least one plane between the focus and the detector.

Abstract: A mobile dual-energy X-ray imaging system is presented. The mobile dual-energy X-ray imaging system is a digital X-ray system that is designed both to acquire original image data and to process the image data to produce an image for viewing. The system has an X-ray source and a portable flat-panel digital X-ray detector. The system is operable to produce a high energy image and low energy image, which may be decomposed to produce a soft tissue image and a bone image for further analysis of the desired anatomy. The system is disposed on a carrier to facilitate transport. The imaging system has an alignment system for facilitating alignment of the flat-panel digital detector with the X-ray source. The imaging system also comprises an anti-scatter grid and an anti-scatter grid registration system for removing artifacts of the anti-scatter grid from images.

Abstract: A heel effect compensation filter is configured to have a thickness distribution that uniforms an X-ray intensity angular distribution that is nonuniform in the body axis direction of a subject in an X-ray flux irradiated space. The space is formed by an X-ray flux diverging from an anode in a body width direction of the subject and diverging in a shape of an approximate sector in the body axis direction due to the heel effect, when the X-ray flux generated on the anode by irradiating a thermoelectron beam flux from a cathode to the anode is irradiated on the subject. The thickness distribution can be obtained using a predetermined formula.

Abstract: A radiation emitting source includes a radiation emitter, an emitter switch, a collimator, a rotating mechanism and a shielding enclosure. The collimator has a central axial through-hole portion and a plurality of radial apertures. The through-hole portion receives the radiation emitter therein. The radiation emitter is axially movable in the through-hole portion. The rotating mechanism is coupled to the collimator. The shielding enclosure has an opening and encloses the collimator therein.

Abstract: The invention relates to an optical device intended to treat an incident X-ray beam. The optical device comprises a monochromator and an optical element for conditioning the incident beam. The reflective surface of the optical element is able to produce a two-dimensional optical effect in order to adapt a beam in destination of the monochromator. The reflective surface of the optical element comprises a multilayer structure type surface that is reflective to X-rays. In particular, the reflective surface consists of a single surface shaped according to two curvatures corresponding to two different directions.

Abstract: An anti-scatter grid for radiology imaging having an anti-scatter layer with a plurality of metallized partitions that enable X-rays emitted from a source located above the grid to pass and absorbing X-rays not derived directly from this source. The grid has at least one plate of expanded polymer material fixed on one surface of anti-scatter layer. The grid may be positioned with a frame.

Abstract: A method and an arrangement for an intelligent adaptive x-ray imaging system, in which the exposure conditions of the object to x-rays is dynamically controlled and optimized in real-time in order to provide the optimum diagnostic information. The arrangement splits the imaging beam into two separate fan beams that scan over the object in a single pass, where the first beam (scout) collects information from the object, that is analyzed to control the intensity or spectral quality or spatial distribution of the second beam (I-ImaS). The CMOS image sensors deployed in the arrangement are able to process detected information either on-chip or within a field programmable gate array, so as to compute a measure related to the diagnostic value of the information.

Abstract: An X-ray examination apparatus changes a position of each X-ray sensor by rotating a sensor base, and resets a starting position of X-ray emission that becomes a X-ray focal position so that the X-ray enters each X-ray sensor after the position thereof is changed. A scanning X-ray source deflects an electron beam to easily change the position where the electron beam impinges a target of the X-ray source to an arbitrary location. The irradiating position of the electron beam then can be easily moved according to an accumulated irradiation time on the target. Therefore, maintenance can be performed without interrupting the X-ray examination.

Abstract: An assembly comprising a radiation source to generate a beam of radiation, a modulator for modulating the power of the beam of radiation as a function of the position of the beam within a field-of-view to maintain the beam's power within a desired exposure level as the beam scans the field-of-view, and a reflector oscillating in a sinusoidal manner to direct the beam of radiation onto a field-of-view.

Abstract: An apparatus directing x-rays along a predetermined axis includes an x-ray optic having one or more nested x-ray reflector rings positioned relative to a source generating broad spectrum x-rays so that generated x-rays moving away from the predetermined axis are collected by the reflector incident at or close to a Bragg angle to thereby reflect the collected x-rays into a conically parallel beam. A first diffractor is positioned relative to the x-ray optic to receive incident thereon the conically parallel beam, the first diffractor selected from a truncated cone and a cylinder and diffracting the conically parallel beam toward the predetermined axis. A second diffractor is positioned relative to the first diffractor and having a geometry effective to receive incident thereon and redirect the conically parallel beam along the predetermined axis as a collimated beam of substantially parallel x-rays.

Abstract: An illumination system for scannertype microlithography along a scanning direction with a light source emitting a wavelength especially ?193 nm. The illumination system includes a plurality of raster elements. The plurality of raster elements is imaged into an image plane of the illumination system to produce a plurality of images being partially superimposed on a field in the image plane. The field defines a non-rectangular intensity profile in the scanning direction.

Abstract: in a diaphragm device for an x-ray apparatus for scanning a subject with a radiation beam and a scanning method using such a diaphragm device, the diaphragm device has at least two diaphragms. For at least one segment of the scan, the radiation beam that has been adjusted with the first diaphragm can be at least partially dynamically masked by the second diaphragm. High adjustment precisions for precise exposure of a measurement field of detector and high adjustment speed for masking of a radiation beam that is not needed for reconstruction of an image, or for reduction of a radiation exposure of the subject can be implemented to equal degree with the two diaphragms that are separate from one another.

Abstract: The invention provides a method and imaging system for operating imaging computed tomography using a radiation source and a plurality of detectors to generate an image of an object. The method includes: defining a desired image characteristics; and performing calculations to determine the pattern of fluence to be applied by the radiation source, to generate said desired image quality or characteristics. Then, the radiation source is modulated, to generate the intended pattern of fluence between the beam source and the object to be imaged. The desired image characteristics can comprise at least one of desired levels of contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR), and may provide at least one of: desired image quality in at least one defined region of interest; and at least one desired distribution of said image quality.

Abstract: Various mechanisms are provided relating to plasma-based light source that may be used for lithography as well as other applications. For example, a device is disclosed for producing extreme ultraviolet (EUV) light based on a sheared plasma flow. The device can produce a plasma pinch that can last several orders of magnitude longer than what is typically sustained in a Z-pinch, thus enabling the device to provide more power output than what has been hitherto predicted in theory or attained in practice. Such power output may be used in a lithography system for manufacturing integrated circuits, enabling the use of EUV wavelengths on the order of about 13.5 nm. Lastly, the process of manufacturing such a plasma pinch is discussed, where the process includes providing a sheared flow of plasma in order to stabilize it for long periods of time.

Abstract: An apparatus and method of attenuating radiation includes oscillating at least one fluid having a radiation attenuating property between at least two chambers, incident to applied radiation. The radiation attenuating device includes at least two communicating adjacent chambers, at least one fluid having radiation attenuating properties moveable between the at least two chambers, and a control circuit configured to oscillate the at least one fluid between the chambers.

Abstract: A system for and a method of controlling a spatial distribution of radiation intensity in a beam of radiation is provided. The system includes a control device located to receive the initial beam of radiation from the radiation source. The control device includes a first radiation absorbing structure located at a position in generally superposing alignment relative a position of a second radiation absorbing structure. Each first and second radiation absorbing structure is operable to independently articulate. The modulator configuration signal is operable to cause adjustment of the position of at least one of the first and second radiation absorbing structures relative to the other so as to selectively adjust a spatial distribution of radiation intensity of a modulated beam.

Abstract: There is provided an illumination system. The illumination system includes a first light source and a second light source, each of which are for providing light having a wavelength ?193 nm, and an optical element. The first light source illuminates a first area of the optical element and the second light source illuminates a second area of the optical element.

Abstract: The present invention discloses a ray beam guiding apparatus, comprising a ray beam guiding box having substantially fan-shaped top and bottom surfaces, defining an inner space, and having open wide and narrow ends; an engaging member joined to the narrow end of the box; a first collimator mounted to the box adjacent to the narrow end for adjusting size/shape of the ray beam in horizontal vertical direction; a second collimator having a calibration slit or grill and mounted to the box adjacent to the wide end; and an adjusting member connecting the engaging member and a ray generator to adjust a distance therebetween. The box can adjust size/shape and centering of the ray beam, so that inspection quality can be improved and thickness of the ray shielding layer can be reduced, the box is applicable to a ray inspection system which performs security inspection of liquid articles.

Abstract: A sample which includes a region exhibiting a large density change, such as, bones or lungs and a region exhibiting a small density change, such as, biological soft tissues, and whose measurement is difficult to do for conventional absorption and phase contrast X-ray imaging apparatuses is highly sensitively imaged and observed. In a phase contrast X-ray imaging apparatus using an X-ray interferometer, a reference object whose shape and internal density distribution are analogous to those of a sample and which is known is positioned on an optical path other than an optical path in the interferometer on which the sample is positioned.

Abstract: There is provided a projection exposure system operable in a scanning mode along a scanning direction. The projection exposure system includes a collector that receives light having a wavelength ?193 nm and illuminates a region in a plane. The plane is defined by a local coordinate system having a y-direction parallel to the scanning direction and an x-direction perpendicular to the scanning direction. The collector includes (a) a first mirror shell, (b) a second mirror shell within the first mirror shell, and (c) a fastening device for fastening the first and second mirror shells. The mirror shells are substantially rotational symmetric about a common rotational axis. The fastening device has a support spoke that extends in a radial direction of the mirror shells, and the support spoke, when projected into the plane, yields a projection that is non-parallel to the y-direction.

Abstract: The invention provides an optical reflector element (1) for a beam of X-rays (RX) or of gamma-rays or of high-energy particles at grazing incidence, the element being constituted by a stack of superposed silicon plates (10-12). Each plate (10-12) has a reflecting top face (101-121) possibly coated with a metallic film, a multilayer or a dispersive grating and a bottom face carrying ribs (100-120) forming spacers between two successive plates (10-11, 11-12), and defining determined spacing between two successive reflecting faces (101-121). The invention also provides optical instruments comprising several such elements, in particular a type I Wolter telescope comprising two mirrors in tandem having respective paraboloid and hyperboloid surfaces of revolution or a conical approximation thereof or a Kirkpatrick-Beaz system.

Abstract: A gating device to delimit an x-ray beam, has a device housing, first and second absorber elements mounted in the device housing opposite each other, and an adjustment device for moving the absorber elements relative to each other to set a spacing therebetween forming a slit for passage of an x-ray beam therethrough. Each absorber element has an edge shaped to give the slit a slit width that varies in a longitudinal direction of the slit that increases outwardly from a central position toward respectively opposite ends of the slit. Each slit edge has a middle region producing a uniform width of the slit and further regions respectively disposed on opposite sides of the middle region that produce a linearly, longitudinally increasing slit width. The adjustment device produces a parallelogram-like relative movement between the absorber elements.