Abstract: A method is for providing a second artifact-reduced x-ray image dataset based on an artifact-affected x-ray image dataset of an examination object, the artifact being caused by an object at least one of on, outside of and within the examination object. In an embodiment, the method includes creating a first artifact-reduced x-ray image dataset based on the artifact-affected x-ray image dataset, based on which a second projection dataset is created; identifying an object area which maps the object in the at least one projection; creating a third projection dataset based on the first projection dataset; and crating the second artifact-reduced x-ray image dataset based on the third projection dataset, through which the second artifact-reduced x-ray image dataset is provided.

Abstract: In a method and a system for authenticating an object marked with XRF marking, a wavelength spectral profile is provided of a detected portion of an X-Ray signal arriving from an object in response to X-Ray or Gamma-Ray radiation applied to the object and the wavelength spectral profile is filtered to suppress trend and periodic components from the wavelength spectral profile to obtain a filtered profile with improved signal to noise or signal to clutter ratio. The object can be authenticated by processing the filtered profile and identifying one or more peaks therein, which satisfy a predetermined condition, whereby the wavelengths of the identified peaks are indicative of the signatures of materials included in the object.

Abstract: There are disclosed a collimator, a radiation emitting assembly and an inspection apparatus. The collimator is configured to collimate radiation from a radiation emitter. One of the collimator and the radiation emitter is provided with a protrusion portion and the other is provided with a recess portion such that the protrusion portion is capable of being placed within the recess portion and the radiation emitter and the collimator are allowed to be arranged close to and connected with each other, and that the radiation passes through passages in the protrusion portion and the recess portion from the radiation emitter to the collimator.

Abstract: An energy degrading device for attenuating energy of a particle beam with reduced emittance growth. An energy degrader comprises an emittance control material that can preferentially scatter the beam particles that is incident on a surface with a shallow angle. In one approach, the energy degrader may include alternating layers of a low-Z and a high-Z material, wherein the low Z material serves to attenuate energy of the beam particles by virtue of scattering and the high Z material serves to suppress the emittance increase by scattering back the beam particles toward the beam axis. In another approach, the energy degrader may be composed of carbon nanotubes or a material with oriented crystalline structure that is substantially orientated in the incident direction of the particle beam. The carbon nanotubes may serve to preferentially scatter beam particles towards the central beam axis as well as attenuate energy thereof.

Abstract: The invention relates to a device (10) for determining spatially dependent x-ray flux degradation and photon spectral change, a system (1) for determining spatially dependent x-ray flux degradation and photon spectral change for an x-ray tube (20), a method for spatially dependent x-ray flux degradation and photon spectral change for an x-ray tube (20), a computer program element for controlling such device (10) or system (1) for performing such method and a computer readable medium having stored such computer program element. The device (10) for determining spatially dependent x-ray flux degradation and photon spectral change comprises an acquisition unit (11), a processing unit (12), a calculation unit (13), and a combination unit (14). The acquisition unit (11) is configured to acquire x-ray flux degradation data for the x-ray tube (20). The processing unit (12) is configured to process the x-ray flux degradation data into spatially dependent flux degradation data.

Abstract: An X-ray diagnostic apparatus according to the embodiment includes an X-ray tube, an X-ray detector, image generating unit generating time-series medical images of vasoganglion in a predetermined organ of a subject, region setting unit setting a first upstream and downstream region of a stenosis location in a first blood vessel in the vasoganglion on the medical images, curve generating unit generating a stenosis upstream and downstream curve indicating a change in pixel value in the time-series based on pixel values included in the first upstream and downstream region respectively, stenosis index generating unit generating a stenosis index indicating the degree of stenosis in the first blood vessel based on the stenosis upstream and downstream curve, and display unit displaying the stenosis index.

Abstract: An imaging system is provided including a selectable pre-object filter module, a detector, and a processing unit. The selectable pre-object filter module is configured to absorb radiation from the X-ray source to control distribution of X-rays passed to an object to be imaged. The selectable pre-object filter module has plural pre-object filter configurations providing corresponding X-ray distributions, and is selectable between the plural configurations to provide a selected pre-object filter configuration for a scan of the object. The detector is configured to receive X-rays that have passed through the object.

Abstract: The invention relates to a system (100) for generating and collimating an X-ray beam (104), comprising an X-ray tube insert for generating the X-ray beam, the X-ray tube inert being a vacuum tube; a tube housing (102) for containing the X-ray tube insert (101), the tube housing being made of X-ray absorbing material; a collimator (103) for collimating the X-ray beam (104); wherein the collimator (103) is arranged in between the X-ray tube insert (101) and the tube housing (102). The invention also relates to a corresponding apparatus for scanning an object of interest with an X-ray beam (104) comprising the system.

Abstract: In a beam filter assembly, a base filter is employed to modify a beam quality of a radiation beam of a base energy level and a first filter slice is stacked with the base filter to modify a beam quality of a radiation beam of a first energy level higher than the base energy level. In a beam filter positioning device, a base stage carries a base filter and a first stage carries a filter slice. The base stage is provided with a first engagement site and a second engagement site. The first stage is provided with a first engagement site, a second engagement site, and an open port. The first stage and the base stage are each independently movable relative to the beamline. The first stage is engageable with the base stage when at least one of the first and second engagement sites of the first stage is aligned with at least one of the first and second engagement sites of the base stage, and is further movable with the base stage in unison when engaged.

Abstract: A radiation image acquiring system is provided. An X-ray image acquiring system irradiates X-rays to a subject from an X-ray source, and detects X-rays transmitted through the subject. The X-ray image acquiring system includes a first detector for detecting X-rays that are transmitted through the subject to generate first image data, a second detector arranged in parallel to the first detector with a dead zone region sandwiched therebetween, for detecting X-rays that are transmitted through the subject to generate second image data, and a timing control section for controlling detection timing of the second detector based on a dead zone width of the dead zone region so that first image data to be generated by the first detector and second image data to be generated by the second detector mutually correspond.

Abstract: Provided is a dual-energy ray scanning system, which includes a ray source for alternately emitting a high energy ray and a low energy ray; a filter includes a low energy filtering element and a low energy transmitting element; a control device for synchronously controlling the ray source and the filter, and the low energy filtering element includes a plurality of filter sheets, the low energy transmitting element comprises a plurality of transmission sheets, the filter sheets and the transmission sheets are arranged alternately and surround the ray source to form a cavity, and the ray source is located on a central axis of the cavity.

Abstract: A filter is disclosed for the spectral filtration of X-rays emanating from an X-ray source which cross an object under examination and are detected by an X-ray detector in at least two different spectral regions. After crossing the object under examination, the X-rays have an energy spectrum which displays a characteristic distribution for the anode material of the X-ray source. In an embodiment, the filter is configured to suppress part of the energy spectrum comprising the focal point of the energy spectrum. A corresponding X-ray system and method are also disclosed.

Abstract: Dynamic bowties, imaging systems including a bowtie, and methods of imaging including such bowties or systems are provided. A bowtie can be a three-dimensional (3-D) dynamic bowtie and can include a highly-attenuating bowtie (HB) and a weakly-attenuating bowtie (WB). The HB can be filled with a liquid, and the WB can be immersed in the liquid of the HB.

Abstract: The invention provides methods, systems and detector arrangements for scanning an object moving in a first direction that includes the steps of irradiating the object with radiation having a peak energy of at least 900 keV, providing a first detector region having a thickness of at least 2 mm and a second detector region having a thickness of at least 5 mm where the second detector region is arranged to receive radiation that has passed through the first detector region, and detecting the radiation after it has interacted with or passed through the object in order to provide information relating to the object.

Abstract: An apparatus comprising a variable aperture for controlling electromagnetic radiation and related systems and methods are described. In one aspect, a variable aperture to control electromagnetic radiation comprises a first substrate, a second substrate, an attenuation fluid, at least one charging electrode, and at least one displacing electrode. The second substrate is located opposite the first substrate and spaced apart from the first substrate to form a gap between the first substrate and the second substrate. The attenuation fluid is located in the gap and configured to absorb electromagnetic radiation of a predetermined wavelength. The at least one charging electrode is in electrical contact with the attentional fluid. The at least one displacing electrode is located on a surface of the first substrate facing the gap or on a surface of the second substrate facing the gap.

Abstract: Masks that selectively attenuate radiation for inspections of printed circuit boards (PCB) are disclosed. A PCB may be inspected for defects by exposing the PCB with radiation and analyzing the radiation transmitted through the PCB. By employing a radiation mask having first and second segments between the PCB and a radiation source, the radiation may be selectively attenuated to attenuate a first portion of the radiation with a first attenuation level to prevent performance degradation to sensitive semiconductor devices as part of a first sectional area of the PCB, and yet provide substantially non-attenuation or attenuation at a second attenuation level for a second portion of the radiation incident upon a second sectional area of the PCB which is free from sensitive semiconductor devices. In this manner, the selective attenuation enables inspection of the first and second sectional areas of the PCB without damage to the sensitive semiconductor devices.

Abstract: An X-ray source is disposed and a detector is disposed adjacent to the X-ray source. A test specimen holder is disposed between the X-ray source and the detector. A filter is disposed between the X-ray source and the test specimen holder. The filter has a plate-shaped semiconductor, a granular semiconductor, or a combination thereof.

Abstract: A method is disclosed for generating at least one x-ray image of a patient having incorporated contrast medium, using x-rays having an energy spectrum and an x-ray detector. The energy spectrum is modified by at least one first filter arranged in the beam path in front of the patient, the patient absorbing a dose in order to generate detector data for the x-ray image and the x-ray image having a CNR value which represents the ratio of the maximum contrast in the image to the noise. The energy spectrum and contrast medium are matched to each other, taking into account the thickness of the patient to be x-rayed, in such a way that an optimization criterion which is taken from an x-ray image that is generated or simulated by way of trials is maximized. Furthermore, an x-ray system is also disclosed.

Abstract: A method and imaging system for operating imaging computed tomography using at least one radiation source and at least one detector to generate an image of an object. The method includes: defining desired image characteristics; and performing calculations to determine the pattern of fluence to be applied by the at least one radiation source, to generate said desired image quality or characteristics. Then, the at least one 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 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: The present invention pertains to a system and method for adaptive X-ray filtration comprising a volume of X-ray attenuating material with a central less attenuating three-dimensional region. The volume of X-ray attenuating material can be positioned within 10 cm from an X-ray source and rotated around an internal axis of rotation. The volume of X-ray attenuating material can be symmetric around the internal axis while the central less attenuating region can be asymmetric around the internal axis. Rotating the volume by a predetermined angle around the internal axis can change the amount of attenuation of an X-ray beam through the filter. The volume can be rotated by the same predetermined angle as an imaging subject or X-ray source and detector are rotated during X-ray image acquisition.

Abstract: An imaging system (300) includes a radiation source (308) that emits radiation from a focal spot (312) in a direction of an examination region. The imaging system further includes a beam shaper (314), located between the focal spot and the examination region, that shapes an x-ray transmission profile of the radiation emitted from the source and incident on the beam shaper such that the radiation leaving the beam shaper has a pre-determined transmission profile.

Abstract: A determination section of an FPD checks external information against a determination table and determines whether detection of a rise of X-ray pulses is allowed based on an output voltage from a short-circuited pixel. The FPD detects X-ray images. The external information is transmitted from an imaging control device. The X-ray pulses are sequentially generated by an X-ray generating apparatus. A controller selects a pulse irradiation mode in a case where the detection of the rise of the X-ray pulse is allowed. If not, a successive irradiation mode is selected. In the pulse irradiation mode, the rise and the fall of the X-ray pulse are detected and timing of storage operation is synchronized with the detected timing of the rise. In the successive irradiation mode, the storage operation is performed at predetermined time intervals without the detection of the rise and the fall of the X-ray pulse.

Abstract: An adaptive x-ray filter for changing a local intensity of x-rays includes an x-ray absorbing first fluid and electrically deformable control elements. The electrically deformable control elements change a layer thickness of the first fluid at a site of a respective electrically deformable control element by at least partially displacing the x-ray absorbing first fluid.

Abstract: An adaptive X-ray filter for varying a local intensity of X-ray radiation includes a first chamber containing a magnetorheological or electrorheological first liquid, a second chamber containing a second liquid that absorbs X-ray radiation, and a flexible membrane that separates the first chamber from the second chamber. Using the flexible membrane, a layer thickness ratio of the first liquid and the second liquid may be varied. A heating apparatus that heats the second liquid is arranged in the adaptive X-ray filter. The second liquid is a liquid metal.

Abstract: A filtering device includes an X-ray translucent substrate having a plurality of septa disposed therein at a plurality of fixed positions with respect to the substrate. A controller is programmed to acquire a first set of projection data at a first energy spectrum by controlling the X-ray source to emit the X-rays at the first energy spectrum and controlling the position of the filtering device to focally align the plurality of septa with the X-ray beam emitted from the focal spot, and to acquire a second set of projection data at a second energy spectrum with a mean energy greater than the mean energy of the first energy spectrum by controlling the X-ray source to emit the X-rays at the second energy spectrum and controlling a change in the position of the filtering device to focally misalign the plurality of septa with the X-ray beam emitted from the focal spot.

Abstract: An imaging system includes a radiation source (310) configured to rotate around an examination region about a z-axis and having a focal spot that emits a radiation beam that traverses the examination region. The system further includes a radiation sensitive detector array (314) with a plurality of detector pixels that detects radiation traversing the examination region and generates projection data indicative of the detected radiation. The system further includes a dynamic post-patient filter (316) including one or more filter segments (402, 802, 902, 1004, 1102). The filter is configured to selectively and dynamically move in front of the detector array between the detector array and the examination region and into and out of a path of the radiation beam illuminating the detector pixels during scanning an object or subject based on a shape of the object or subject, thereby filtering unattenuated radiation and radiation traversing a periphery of the object or subject.

Abstract: An image reconstruction method for differential phase contrast imaging includes receiving data corresponding to a signal produced by an X-ray detector and corresponding to X-rays that passed through a subject and a grating system to reach the X-ray detector. The method also includes performing a fringe analysis on the received data. The fringe analysis includes a non-integer fringe fraction correction utilizing one or more adapted basis functions in the Fourier domain to determine one or more Fourier coefficients. A differential phase image of the subject is generated by utilizing the one or more Fourier coefficients.

Abstract: A medical imaging system adaptively acquires anatomical images using a shape adaptive collimator including multiple different portions of X-ray absorbent material automatically adjustable to alter the dimensions of a spatial cross section of an X-ray beam of radiation into a non-rectangular shape, in response to a control signal. The synchronization processor provides a heart rate related synchronization signal derived from a patient cardiac function related parameter. The synchronization signal enables adaptive variation in timing of image acquisition within an individual heart cycle and between successive heart cycles of each individual image frame of multiple sequential image frames. The X-ray image acquisition device uses the shape adaptive collimator for acquiring anatomical images of the region of interest with reduced patient X-ray exposure in response to the synchronization signal. A display processor presents resultant images.

Abstract: A CT system includes an x-ray source configured to project an x-ray beam toward an object, a detector array, and a bowtie filter. The bowtie filter includes a first x-ray filtration region positioned to attenuate x-rays that pass through an isochannel of the detector array, a second x-ray filtration region positioned to attenuate x-rays that pass through channels of the detector array that are offcenter in a channel direction from the isochannel, and an x-ray attenuation material positionable to attenuate the x-rays that pass through the channels of the detector array that are offcenter in the channel direction from the isochannel. The CT system also includes a data acquisition system (DAS) connected to the detector array and configured to receive outputs from the detector array, and a computer programmed to acquire projections of imaging data of the object, and generate an image of the object using the imaging data.

Abstract: The invention concerns a device and a process for adjusting the range of an ion beam, in particular for irradiation in tumor therapy. For this purpose, first the reference position of a target volume to be irradiated is determined. Subsequently, the range of an ion beam is configured such that said beam is adjusted to the reference position of the target volume, in such a manner that the Bragg peak, i.e. the maximal energy loss and thereby the maximal damage occurs in the region of the target volume which is to be destroyed. In the case that it has been determined that the reference position has been altered by a movement of the target volume, the ion beam is then deflected from the beam axis such that the ion beam is directed to various regions of a range modulator, in order that the ion beam experience a correspondingly adjusted energy loss in passing through the range modulator.

Abstract: The invention relates to an improved EUV generating device having a contamination captor for “catching” contamination and/or debris caused by corrosion or otherwise unwanted reactions of the tin bath.

Abstract: A filter for an x-ray device to shape an intensity profile of x-ray radiation emanating from an x-ray source of the device has a filter body made of a material that attenuates x-ray radiation. The filter body is designed with a propeller shape and has two blades connected by an axle of the filter. The filter body is rotatable around the axle, which is permeable to the x-ray radiation. The x-ray device embodies at least one such filter.

Abstract: A system includes a beam filter positioning device including a plate configured to support one or more beam filters, and one or more axes operable to move the plate relative to a beam line. A control mechanism is coupled to the one or more axes for controlling the movement of the axes and configured to automatically adjust the position of at least one of the one or more beam filters relative to the beam line.

Abstract: An adaptive X-ray filter for varying a local intensity of X-ray radiation includes a first chamber containing a magnetorheological or electrorheological first liquid, a second chamber containing a second liquid that absorbs X-ray radiation, and a flexible membrane that separates the first chamber from the second chamber. Using the flexible membrane, a layer thickness ratio of the first liquid and the second liquid may be varied. A heating apparatus that heats the second liquid is arranged in the adaptive X-ray filter. The second liquid is a liquid metal.

Abstract: An adaptive x-ray filter and an associated method for changing a local intensity of x-ray radiation are provided. The adaptive x-ray filter includes a first fluid absorbing x-ray radiation and hydraulically moveable positioning elements that change the layer thickness of the first fluid at a location of the respective positioning element by being able to at least partly displace the first fluid.

Abstract: A motor controller determines a drive speed of a motor for driving a filter such that an area shifting cycle of the filter synchronizes with a cardiac cycle. The filter starts to rotate before radiation emission, and continues to rotate at a constant speed during two successive radiation emissions. An emission controller controls timing of two emissions in accordance with a phase of the filter. The area shifting cycle of the filter and the cardiac cycle are previously synchronized, and thus a high-performance filter switching device for switching or shifting the filter in synchronization with the emission timing becomes unnecessary. Adjusting the area shifting cycle of the filter in accordance with the cardiac cycle realizes two radiation emissions in two successive cardiac cycles. As a result, an exposure time is shortened.

Abstract: An X-ray measurement apparatus includes an X-ray source configured to emit an X-ray to irradiate a specimen with the X-ray, a collimator configured to shape a beam of the X-ray emitted from the X-ray source into a sliced fan-shaped beam x-ray, a flux shield configured to block a part of a flux of the fan-shaped beam X-ray so as to suppress beam hardening while adjusting an energy intensity distribution of the flux, the flux shield being placed between the collimator and the specimen, and an X-ray detector configured to detect a dose transmitted through the specimen.

Abstract: An arrangement and a method are disclosed for projective and/or tomographic phase-contrast imaging using X-ray radiation. In at least one embodiment, one or more phase grids is/are arranged in the beam path such that during a rotation of the at least one X-ray source, the examination object is scanned with different spatial orientations of the grid lines relative to the examination object such that the complete refraction angle, and hence the complete phase shift gradient, can be determined for each X-ray beam from the two scans with differently oriented phase grids in order to be able to show the phase shift of an examination object in terms of projections or in a tomographic image.

Abstract: This invention relates to a method and an apparatus, primarily a radiation imaging apparatus and an array of coded aperture masks, for use in diagnostic nuclear medicine. The coded aperture masks are fitted with radiation attenuation tubes, each of which extends from each side of the mask in the direction of the mask apertures. The tubes are made from lead and have parallel sides. The masks are configured for gamma ray usage and are made from tungsten having a thickness of between 1 and 2 mm.

Abstract: A filter capable of adjusting spectrum in multiple stages and that capable of attaining the reduction of size, as well as an X-ray imaging system having such a filter, are provided. The filter, which is for adjusting the spectrum of passing radiation, comprises a support plate having an aperture for passage therethrough of radiation, plural filter plates supported by the filter plate and having mutually different filter characteristics, and moving device for moving the plural filter plates selectively to a position to close the aperture and a position to open the aperture.

Abstract: A lithographic apparatus includes an illumination system configured to condition a radiation beam, a projection system configured to project the radiation beam onto a substrate, and a filter system for filtering debris particles out of the radiation beam. The filter system includes a plurality of foils for trapping the debris particles, a support for holding the plurality of foils, and a cooling system having a surface that is arranged to be cooled. The cooling system and the support are positioned with respect to each other such that a gap is formed between the surface of the cooling system and the support. The cooling system is further arranged to inject gas into the gap.

Abstract: A system for modulating a fan beam for radiation treatment employs shutters that may move rapidly into and out of different beamlets of a fan beam, the shutters having a systematic weighting so that a limited number of shutters may obtain a far greater number of regularly spaced energy reductions.

Abstract: A filter changing assembly that can be used in, for example, a radiology system includes shape filters that can used to shape a radiation beam and that can be moved back-and-forth, for example. The filter changing assembly also includes beam hardening filters that can be used to change the energy spectrum of the radiation beam, and that also can be moved back-and-forth, for example. The filter changing assembly includes a control system that can be used to select at least one of the filters and automatically move the selected filter from one position to another position.

Abstract: A computed tomography scanner is disclosed for performing a spiral scan. In at least one embodiment, the computed tomography scanner includes a rotatable X-ray emitter for generating a beam fan and an X-ray detector, positioned diametrically opposite to the emitter, and an associated evaluation unit. In at least one embodiment, provision is made for an X-ray filter arranged downstream of the X-ray emitter, the position of the X-ray filter being correlated to that of the X-ray detector. Further, the X-ray filter is partly inserted into the beam fan only during operation for generating an unfiltered and, simultaneously, a filtered radiation component of the beam fan, wherein the radiation components have different X-ray spectra and wherein the evaluation unit is designed for separate evaluation of a measurement signal of the unfiltered radiation component and a measurement signal of the filtered radiation component, to obtain dual-energy images.

Abstract: A source of pulsed radiation is coupled to a positionable filter. The positionable filter includes an element that produces an indication of a position of the filter. The source is configured to receive the indication of the position of the filter, and to regulate emission of a pulse of radiation based on the indication. A device includes an area including a material that alters a parameter of a beam of radiation that interacts with the material. The device is configured to move relative to a source of pulsed radiation. An element provides a signal to the source of pulsed radiation that indicates a position of the area relative to the source. The signal causes the source to trigger emission of a pulse at a time such that the emitted pulse is incident upon a portion of the area.

Abstract: The invention is directed to an x-ray flux management device that adaptively attenuates an x-ray beam to limit the incident flux reaching a subject and radiographic detectors in potentially high-flux areas while not affecting the incident flux and detector measurements in low-flux regions. While the invention is particularly well-suited for CT, the invention is also applicable with other x-ray imaging systems. In addition to reducing the required detector system dynamic range, the present invention provides an added advantage of reducing radiation dose.

Abstract: For use with an irradiation system including a radiation source operable to produce a radiation beam towards a target, a beam modulator including a flexible, deformable container at least partially filled with a radiation attenuating fluid, a non-deformable first contacting surface in contact with a first portion of the container, the first contacting surface pivotable about a first axis, and a positioner operable to rotate the first contacting surface about the first axis, wherein as the first contacting surface rotates about the first axis, the first contacting surface deforms the container.

Abstract: This invention relates to a method and an apparatus, primarily a radiation imaging apparatus and an array of coded aperture masks, for use in diagnostic nuclear medicine. The coded aperture masks are fitted with radiation attenuation tubes, each of which extends from each side of the mask in the direction of the mask apertures. The tubes are made from lead and have parallel sides. The masks are configured for gamma ray usage and are made from tungsten having a thickness of between 1 and 2 mm.

Abstract: A shielding device (20) for optical and/or electronic apparatuses (16) is described, wherein said apparatuses may cooperate with incident electromagnetic radiation (X1, X2), in particular for space telescopes, the shielding device including: at least a filter (24, 26) provided for interacting with said incident electromagnetic radiation (X1, X2), for selectively filtering said radiation; and a support structure (22) for the filter. The support structure (22) is an inflatable structure, which is able to achieve an operating stand-by configuration, in which it is substantially folded together, and an active operating configuration, in which it extends along the longitudinal extension axis (ZZ), and is essentially completely unfolded. Furthermore, the filter (24, 26) includes a filter body, which is provided in order to be transversely positioned with respect to said longitudinal extension axis, when the support structure reaches its active operating configuration.

Abstract: An apparatus, suited, for example, for extreme ultraviolet lithography, includes a radiation source and a processing organ for processing the radiation from the radiation source. Between the radiation source and the processing organ a filter is placed which, in the radial direction from the radiation source, comprises a plurality of foils or plates.