Abstract: An X-ray computer tomography apparatus includes an X-ray tube, an X-ray detector, a data collection apparatus that collects X-ray signals from the X-ray detector repeatedly, a shutter mechanism that is arranged between the X-ray tube and a subject in order to convert an X-ray into a pulse-like X-ray and is constituted such that a ratio of a shutter open period and a shutter close period is variable, a restructuring unit that restructures image data on the basis of the collected X-ray signals, and a control unit that controls the shutter mechanism in order to change the ratio of a shutter open period and a shutter close period during a helical scan.

Abstract: A method for inspection of a sample includes directing a beam of X-rays toward a sample and configuring an array of detector elements to capture the X-rays scattered from the sample. The sample is shifted in a direction parallel to the axis of the array between at least first and second positions, which positions are separated one from another by an increment that is not an integer multiple of the pitch of the array. At least first and second signals are generated by the detector elements responsively to the X-rays captured thereby while the sample is in at least the first and second positions, respectively. The first and second signals are combined so as to determine an X-ray scattering profile of the sample as a function of position along the axis.

Abstract: A chopper for an imaging system includes a frame and a sheet that have different coefficients of thermal expansion. The frame has a space within it, and has at least one opening that allows radiation to pass through the space. The sheet has structure which influences radiation passing through the sheet, and the sheet is movably disposed within the space in the frame, in a manner so that the sheet can expand and contract relative to the frame in a direction approximately parallel to the sheet. The frame prevents any significant movement of the sheet in a direction transverse to the sheet.

Abstract: A method of performing a medical procedure includes providing a radiation-shielding cubicle having an interior defining a medical personnel region and including a first wall having an opening therein, locating the cubicle with respect to an x-ray table so a portion of the x-ray table extends through the opening into the interior of the cubicle, and separating medical personnel from an x-ray emitter disposed outside of the cubicle using the first wall to shield the medical personnel from radiation emitted by the x-ray emitter.

Abstract: An X-ray diagnostic device has an X-ray tube and a diaphragm housing in which diaphragm plates for limiting an X-ray field are contained, as are a lamp and a mirror. The lamp and mirror are configured so that, when the lamp is on, the light therefrom is reflected by the mirror so that the reflected ray field coincides with the hypothetical X-ray field. At least one filter for filtering the X-rays is disposed in the diaphragm housing. The mirror and the filter or filters are attached to a single disk that rotates around an axis such that either the mirror or a filter is within the hypothetical X-ray field.

Abstract: A shutter-shield system for radiation protection is applied to a an x-ray generator in a shielded station for inspecting products moving through the station on a conveyor. Deployed in a sliding attachment on a collimator housing of the x-ray generator, a shutter plate is made movable by an actuator and is configured with an aperture that, in the absence of power applied to the actuator, is made to align with a fixed aperture of the collimator so as to allow emission of the x-ray beam as required for normal inspection purposes. Whenever an anomaly in the product loading on the conveyer creates a gap that could otherwise cause an increase in environmental radiation levels, powering the actuator moves the shutter plate to an offset location that offsets the apertures to an effectively closed state to initiate a standby condition wherein x-ray radiation is substantially confined to the interior region of the collimator, without having to shut down the x-ray generator itself.

Abstract: A system and method for inspecting an object, the system and method comprising a source for generating a penetrating radiation beam for irradiating the object, the beam having, for each instant of time, an instantaneous energy spectrum of intensity, a shaper for modulating the generated beam, thereby creating a shaped beam, the shaper comprising at least a first section and a second section, the first section attenuating the intensity of a portion of the generated beam by a first attenuation factor and the second section attenuating the intensity of another portion of the generated beam by a second attenuation factor, and at least one detector for detecting the shaped beam after the shaped beam interacts with the object. The source may scan a beam across an object while the source and at least one detector are moving on a platform capable of highway travel or on an inspection module movable with respect to the object.

Abstract: A radiation diaphragm for an X-ray apparatus has an absorber element that can be swiveled around a swiveling axis for the variable limitation of a ray bundle. The swiveling axis is oriented transversely to the ray bundle. A swivel arm that can be swiveled around the swiveling axis and that carries the absorber element. The absorber element can comprise a curved shape. Such a radiation diaphragm allows an especially effective radiation dose limitation for the patient.

Abstract: A debris removing system prevents debris from being scattered from an X-ray source. The debris removing system includes an attracting unit, disposed between a light emission point of the X-ray source and the optical system, for attracting debris. The attracting unit has an attracting surface parallel or approximately parallel to an axis passing through the light emission point. The debris removing system further includes a rotation unit for rotating the attracting unit about the axis. This debris removing system assures a superior debris removing effect and a good EUV light utilization efficiency, being compatible with each other.

Abstract: A method of performing a medical procedure includes providing a radiation-shielding cubicle having an interior defining a medical personnel region and including a first wall having an opening therein, locating the cubicle with respect to an x-ray table so a portion of the x-ray table extends through the opening into the interior of the cubicle, and separating medical personnel from an x-ray emitter disposed outside of the cubicle using the first wall to shield the medical personnel from radiation emitted by the x-ray emitter.

Abstract: An X-ray generator comprises an evacuated and sealed X-ray tube, containing an electron gun and an X-ray target. An electron beam is produced by the electron gun in which the cathode is at negative high voltage, the electron gun consisting of a filament just inside the aperture of a Wehnelt grid which is biased negatively with respect to the filament. Two sets of beam deflection coils, are employed in two planes, mounted between the anode of the electron gun and the focussing lens to center the beam. Between the focussing lens and the target is an air-cored quadripole magnet which acts as a stigmator in that it turns the circular cross-section of the beam into an elongated one. This quadripole can be rotated about the tube axis so as to adjust the orientation of the line focus. The beam can be moved about on the target surface by controlling the currents in the four coils of the quadripole.

Abstract: Reflectometry apparatus includes a radiation source, adapted to irradiate a sample with radiation over a range of angles relative to a surface of the sample, and a detector assembly, positioned to receive the radiation reflected from the sample over the range of angles and to generate a signal responsive thereto. A shutter is adjustably positionable to intercept the radiation, the shutter having a blocking position, in which it blocks the radiation in a lower portion of the range of angles, thereby allowing the reflected radiation to reach the array substantially only in a higher portion of the range, and a clear position, in which the radiation in the lower portion of the range reaches the array substantially without blockage.

Abstract: An x-ray shielding system includes a beam controller configured to surround an x-ray source and includes a detector shield configured to position behind an x-ray detector. The beam controller includes a source shield and an aperture. The source shield and the detector shield are adapted to block x-rays, and the aperture is adapted to transmit x-rays. A shielded digital radiographic inspection system includes the x-ray source and the beam controller surrounding the x-ray source. The beam controller includes the source shield and the aperture. The aperture is configured to rotate around the x-ray source. The inspection system further includes a digital x-ray detector positioned radially outward from the x-ray source and facing the aperture. The digital x-ray detector is configured to be movable along an orbit around the x-ray source. The inspection system further includes the detector shield configured to be movable with and positioned behind the digital x-ray detector.

Abstract: A radiation diaphragm for an X-ray apparatus has an absorber element that can be swiveled around a swiveling axis for the variable limitation of a ray bundle. The swiveling axis is oriented transversely to the ray bundle. A swivel arm that can be swiveled around the swiveling axis and that carries the absorber element. The absorber element can comprise a curved shape. Such a radiation diaphragm allows an especially effective radiation dose limitation for the patient.

Abstract: An attachment 3 mounted on a specimen support portion 2 of an X-ray apparatus 1 includes a cover member 9 covering a specimen S and a scattered ray excluding member 8 provided between the cover member 9 and the specimen S. The scattered ray excluding member 8 takes in the form of a box or a case defined by a wall 16. The box has a large opening 14a on the side of the cover member 9 and a small opening 14b on the side of the specimen S. The scattered ray excluding member 8 functions to prevent scattered X-ray emitted from the cover member when X-rays from an X-ray source passes through the cover member 9 and travelling toward an X-ray detector.

Abstract: An inspection system is for inspecting an object with penetrating radiation. A source of penetrating radiation provides a beam of radiation. The beam alternates between a first beam shape and a second beam shape, the first and second beam shapes being coplanar. A first detector arrangement is for detecting penetrating radiation from a portion of the beam transmitted through the object and generating a transmitted radiation signal. A second detector arrangement is for detecting penetrating radiation from a portion of the beam scattered by the object and generating a scattered radiation signal. A processor determines at least one characteristic of the object based at least on the transmitted and scattered radiation signals.

Abstract: The shutters (2) in an X-ray device which include at least a radiation source (1), a diaphragm device (8) with shutters (2) and a recording (3) and image processing unit (4), are provided with hole and/or edge patterns (11-14) which reproduce non-anatomical patterns in the radiation image; the shutter edges (15) are detected in the radiation image in the image processing unit on the basis of such patterns, so that only the directly irradiated part of the patient is displayed.

Abstract: In radiotherapy, a high quality imaging array may be placed after the patient and opposite the radiation source to be used during radiation treatment to verify operation of a shutter system or similar device and/or to compute dose delivered to the patient. A model of the patient may be used and inverted in order to estimate values of energy fluence prior to absorption by the patient and overlapping of the various radiation beams passing through the patient. A test pattern of shutter excitation to illuminate a single ray at a time provides a simple method of obtaining the necessary model. The dose from this test pattern may be subtracted from the subsequent radiation treatment so as to provide limited or no increase in total dose to the patient.

Abstract: An apparatus and method for creating a beam of penetrating radiation of specified cross section that raster scans over a two-dimensional area, using a chopper wheel rotated about two axes. The wheel has a set of apertures of which at least one is illuminated to form the beam. Rotary actuators rotate the wheel about an axis of rotational symmetry of the wheel and about an axis not parallel to the axis of rotational symmetry of the wheel.

Abstract: A fast, economical, and compact x-ray beam chopper with a small mass and a small moment of inertia whose rotation can be synchronized and phase locked to an electronic signal from an x-ray source and be monitored by a light beam is disclosed. X-ray bursts shorter than 2.5 microseconds have been produced with a jitter time of less than 3 ns.

Abstract: Collimator apparatus is provided for an X-ray imaging system comprising an X-ray tube disposed to project an X-ray beam, and a detector spaced apart from the X-ray tube for receiving X-rays of the beam within an Active Imaging Area (AIA). The apparatus comprises a first collimator positioned along the path of the beam, the first collimator being vertically adjustable, and being operable to symmetrically collimate the beam. The apparatus further comprises a second collimating device positioned between the first collimator and the detector. The second collimating device limits the uppermost rays of the symmetrically collimated beam which reach the detector to a predetermined upper boundary. Thus, the second collimating device serves to fix the upper edge of the AIA on the detector.

Abstract: A method and apparatus for producing a scanned beam of penetrating radiation. A beam of particles illuminates a portion of a target, the illuminated portion comprising a focal spot having a centroid. Illumination of the target creates a beam of penetrating radiation such as x-rays. The beam of particles is swept across the target in such a manner that the centroid of the focal spot lies on a line defined by the instantaneous direction of the beam of penetrating radiation as defined, in turn, by a collimating path.

Abstract: An inspection system is for inspecting an object with penetrating radiation. A source of penetrating radiation provides a beam of radiation. The beam alternates between a first beam shape and a second beam shape, the first and second beam shapes being coplanar. A first detector arrangement is for detecting penetrating radiation from a portion of the beam transmitted through the object and generating a transmitted radiation signal. A second detector arrangement is for detecting penetrating radiation from a portion of the beam scattered by the object and generating a scattered radiation signal. A processor determines at least one characteristic of the object based at least on the transmitted and scattered radiation signals.

Abstract: Interrupted-Fan-Beam imaging is a method of producing back-scatter x-ray images from conventional line scan systems, such as those used for luggage and cargo inspection. Since back-scatter and transmission images are formed from different physical principles, the use of both images provides a more thorough security inspection. A mathematical relation relates the signal-to-noise ratio to the spatial resolution in an Interrupted-Fan-Beam image. When used in conjunction with typical operating values of x-ray systems, such as flux level and number of pixels, this relation provides the performance level of the Interrupted-Fan-Beam technique.

Abstract: An arrangement of shutter segments each having longitudinally opposed ends, front and back edges, and top and bottom solid surfaces, wherein each segment is adjacent to at least one other segment. The segments are arranged with the front and back edges of each segment in parallel along a first direction, and with one of the front or back edge of each segment overlapping one of the top or bottom surfaces of an adjacent segment. A drive hub is rigidly connected to each segment, respectively. A drive train engages all of the drive hubs, for simultaneously reciprocating the hubs and connected shutter segments rotatively through an actuation angle of no more than approximately 90 degrees (preferably 45 degrees) around respective axes of rotation which are parallel and coplanar along the first direction.

Abstract: A system and method for inspecting an object, where both a fan beam and a pencil beam of penetrating radiation are used to illuminating the object concurrently. Both beams may be derived from a single source of penetrating radiation. The pencil beam is noncoplanar with the fan beam and may be scanned with respect to the object. Radiation scattered from the pencil beam within the object is detected, and the scatter signal thus generated is used in conjunction with a transmission signal which characterizes attenuation of the fan beam by the object.

Abstract: A casing for an electromagnetic radiation source includes a window made of a material that is transparent to the radiation emitted by the source and which includes at least one chamber in which a material that is opaque to electromagnetic radiation can move. The chamber is designed such that the material that is opaque to radiation can be introduced from the exterior of the chamber. Inside the chamber, the material that is opaque to radiation surrounds a region for passage of a radiation beam such that the area of the beam passage region varies as a function of the volume of opaque material in the chamber, by virtue of which parasitic extrafocal radiation is eliminated from the beam.

Abstract: Thermal imaging chopper (22) having a frame (42) with an open window (47) and a covered window (48). The covered window (48) is preferably covered with a material that partially blocks a selected amount of thermal radiation from a scene and randomly scatters the remaining thermal radiation from the scene that is transmitted through the covered window. The open window (47) allows unrestricted transmission of thermal radiation from the scene.

Abstract: An X-ray system includes a radiation source for producing a radiation beam containing X-rays, a mirror device for reflecting X-rays, a beam duct for introducing the X-rays reflected by the mirror device, to an irradiation zone where an object to be irradiated can be exposed, and a shutter capable of blocking the radiation beam. A protection wall is disposed downstream of the mirror device with respect to the radiation source, for blocking the radiation beam. When the protection wall has a thickness t, the beam duct passing through the protection wall has an opening size a, and the beam duct has a tilt angle .theta., there is a relation (t-t.sub.0) sin .theta..gtoreq.a, where t.sub.0 is a minimum thickness of the protection wall required to substantially block the radiation beam from a radiation source.

Abstract: An image processing method is provided to remove areas from an image made by x-irradiation, said areas corresponding to absorption filters in the x-ray beam. Because such filters, also known as x-ray shutters, are inserted into the x-ray beam from the outside of the x-ray beam, x-ray shutter-areas extend from the periphery of the image. Therefore, once the edge of an x-ray shutter-areas has been determined, the part of the image located between the periphery and the x-ray shutter-edge is removed. X-ray shutter-edges are determined by locating transition-points in the image having brightness-transitions having maxima of both the first and second spatial derivatives of the brightness-value. An x-ray shutter-edge is then determined by fitting a curve through the transition-points. The curve fitting is performed with the use of weight-factors that are representative of the likelihood that a transition-point is on an actual x-ray shutter-edge.

Abstract: A mechanical beam isolator uses rod-shaped elements having a Gaussian configuration to interrupt the path of a beam of photons or particles when the time-scale of the needed interruption is of the order of a microsecond or less. One or more of these rods is mounted transversely to, and penetrates through, a rotating shaft supported by bearings. Owing to the Gaussian geometry of the rods, they are able to withstand much higher rotation speeds, without tensile failure, than rods having any other geometrical shape.

Abstract: Fine, sub-micron line features and patterns are created in a sensitized layer on a semiconductor wafer by a beam of Gamma-radiation. A continuous stream of such radiation, such as provided by a pellet of Cobalt-60, is collimated into a fine beam by a tapered collimator, and is gated on and off by a shutter mechanism comprising a distortable-surface device and a beam-blocking device. The fine, collimated beam converts points in a gamma-radiation-sensitive layer on a semiconductor wafer. By moving the wafer relative to the beam (or vice-versa), patterns are created in the layer of radiation-sensitive layer for further processing a layer underlying the radiation-sensitive layer.

Abstract: In an SOR exposure system for transferring patterns on masks to semiconductor wafers by using SOR radiation reflected by an X-ray reflecting mirror, a first shutter device for shielding at least .gamma. rays and a second shutter device for shielding X-rays are provided between the SOR ring and the mirror inside a beam port, and an exposure adjustment device for adjusting the amount of exposure when a circuit pattern on a mask is transferred to a wafer is provided between the mirror and the wafer. As a result, the human body can be protected against radiation rays, such as gamma rays, generated from the SOR ring when electrons are implanted thereto or when the SOR ring is stopped. Damage to the X-ray reflecting mirror caused by radiation rays is reduced, and stable reflectance of the mirror can be obtained. Maintenance of the SOR exposure system is also made easier.

Abstract: An x-ray beam limiter includes a compressible disc 18 containing an aperture 20 and a slot 22 extending from the aperture to the outer edge 28 of the disc. The outer edge 28 of the disc 18 is covered with a bearing material and is retained within a groove 36 in a bearing retaining race 32 such that the disc 18 is rotatable within the retaining race 32. A beam limiter 54 is mounted to the disc 18. The disc 18 and beam limiter 54 are rotatable between at least two different positions.

Abstract: The invention is an instrument comprising a unit having a frame defining the perimeter about an aperture, and a manually adjustable rack connected to the frame for supporting the unit with its aperture disposed between a source of x-rays and the body of a patient. Radio-opaque flexible panels depending from the frame are pivotable relative to the aperture to collimate and limit x-rays issuing from the source through the aperture to a particular area of the body of the patient. Translucent ports along lower edges of the panels serve to provide upon a photographic film below the patient a scale indication of the area of the body of the patient subjected to the x-rays.

Abstract: A semiconductor device manufacturing SOR X-ray exposure apparatus wherein, after a mask and a semiconductor wafer are aligned, and SOR X-ray is used to transfer a semiconductor device pattern on the mask onto a resist on the semiconductor wafer. The apparatus includes a mirror unit and an exposure unit for exposing the wafer through the mask to the X-ray from the mirror unit. The mirror unit includes an X-ray mirror for diverging the X-ray in a desired direction, a first chamber for providing a desired vacuum ambience around the X-ray mirror and a first supporting device for supplying the X-ray mirror. The exposure unit includes a shutter for controlling the exposure, a mask stage for holding the mask, a wafer stage for holding the wafer, a second chamber for providing a desired He ambience around the mask stage and the wafer stage, a frame structure for mounting the mask stage and the wafer stage and a second supporting device for supporting the frame structure.

Abstract: An x-ray diagnostics installation includes an x-ray tube, a variable aperture diaphragm, and an x-ray image intensifier video chain which includes an x-ray image intensifier, a video pick-up unit, a processing circuit, and a playback unit. The variable aperture diaphragm has a central region and an outer region which exhibit different x-ray transparencies. When adjusted to a first position, the aperture diaphragm permits x-rays to pass only through said central region unattenuated. The aperture diaphragm is adjusted to a second position for every n.sup.th image, wherein both the central region and the outer region permit x-rays to pass through the diaphragm unattenuated. Each n.sup.th image is entered into an image memory connected to the video pick-up unit and is superimposed on an image produced when the diaphragm is in the first position.

Abstract: A shutter mechanism for collimating x-rays uses a frame to define an opening with two opposing interior edges. An elongated flexible band extends in sliding engagement about at least a portion of the periphery of the frame opening. A first shutter member made of an x-ray opaque material has a first end attached to the flexible band along the first interior edge of the frame. Similarly, a second shutter member made of an x-ray opaque material has a first end attached to the flexible band along the second interior edge of the frame. A drive means, such as a stepper motor, translates the flexible band relative to the frame to control the positions of the shutter members and the shutter aperture. In the preferred embodiment, the interior edges of the frame also include tracks that slidably engage the opposing edges of the shutter members for support.

Abstract: An exposure method for manufacture of semiconductor devices, includes moving a shutter having an edge so that the edge is related to a predetermined exposure region; projecting an exposure beam to the edge of the shutter and to at least a portion of the exposure region; determining a position of a shadow of the edge of the shutter formed by the exposure beam with respect to a predetermined coordinate system related to movement of a movable chuck; adjusting the shutter in accordance with the determination; placing a substrate on the chuck; moving the chuck so that the substrate is related to the exposure region; and controlling the exposure of the substrate with the exposure beam through the shutter.

Abstract: Exposure control method and apparatus particularly suitably usable in an X-ray exposure apparatus, for exposing a mask and a wafer to radiation (X-rays) from a synchrotron to transfer a pattern formed on a mask onto the wafer, is disclosed. A shutter device for controlling passage and interception of the synchrotron radiation is provided between the synchrotron and the wafer. The shutter device includes a blade member having a leading edge and a trailing edge which are rectilinearly movable in a direction in which there exists non-uniformness in illuminance of the radiation. The leading edge is used to determine the timing of start of passage of the radiation to the wafer, while the trailing edge is used to determine the timing of interception of the radiation. The moving speeds of the leading edge and the trailing edge are controlled independently of each other to provide different exposure times for different portions of an exposure region on the wafer, in accordance with the non-uniformness in illuminance.

Abstract: In order to perform stereoradiography, an X-ray apparatus utilizes an X-ray tube having a pair of X-ray focal points. The X-ray beams are alternately irradiated from the focal points toward an image intensifier through a patient and are limited by an X-ray beam limiting device. The device shapes the irradiated X-ray beams onto a circular detection surface of the image intensifier into a polygon such as octagon. The X-ray irradiation field on the detection surface can be circumscribed to a circular input window (i.e. effective input area), preventing the field from going beyond the detection surface. Thus, direct X-ray leaking over the image intensifier is avoidable.

Abstract: An apparatus for modulating the intensity of an X-ray beam generated by an X-ray tube. The apparatus comprises a set of at least three blades made of a material opaque to X-ray. Each blade comprises a central hub and a pair of symmetrical wings extending away from the hub. All the blades have their hubs slidably mounted on radially projecting shafts symmetrically positioned about a rotor positioned adjacent the X-ray beam and driven at variable speeds. Matching pins and threads are provided on each pair of hub and shaft to cause the corresponding blade to pivot about the shaft on which it is mounted when the speed of the rotor increases and the blades are then moved in unison radially outwardly against the action of a return spring, because of the centrifugal force. The rotor, the blades and the shafts are positioned and sized to cause the blades to intersect the X-ray beam when the rotor is driven.

Abstract: A lithographic system, having a stepper and exposure station built on a block of granite attached to the ground using isolation legs, includes a servo control system for providing signals a motor associated with the stepper to control the movement of the stepper. The control system includes means to calculate a filter formula used to generate the control signals, which formula is calculated in response to the initial velocity, the movement of the stepper and a certain time between discrete movements, so that a minimum amount of energy is utilized. The filter formula requires that the difference in the velocity of the base and the stepper be zero at the time the stepper reaches the final position. Where time is short, both the base and the stepper initially move with the same velocity and end with the same velocity, and an array processor calculates the time varying filter formula.

Abstract: An X-ray exposure system for exposing a semiconductor wafer to a mask with X-rays contained in synchrotron radiation, is disclosed. In this system, the mask and the wafer are held on a main frame so that their surfaces extend substantially parallel to a vertical axis. The main frame suspends from a supporting frame through a plurality of air mounts, each being vertically displaceable. The supporting frame is placed on the same reference surface as that of an SOR ring that produces synchrotron radiation. By using these air mounts, any tilt of the mask and the wafer relative to the irradiation region of the synchrotron radiation, as well as the position of the mask and the wafer in the vertical direction, with respect to the irradiation region, can be controlled and maintained constant. Thus, accurate pattern printing is ensured.

Abstract: A reliable shutter position indicator for an x-ray diffractometer utilizes an optical shutter position sensor for detecting the position of a shutter of the x-ray diffractometer. In one embodiment, a pair of optical isolators are utilized with an arm coupled to the shutter shifting to a position to interrupt a light beam of the optical isolators when the shutter is in either the open or closed position. The controller of the x-ray diffractometer then compares the detected shutter position with the expected shutter position to determine whether a shutter error is present.

Abstract: An apparatus for slit radiography is provided with a slot diaphragm to form a fan-shaped X-ray beam with which a body can be scanned. Controllable attenuating elements interact with the slit diaphragm to influence sectors of the fan-shaped X-ray beam. They are controlled by signals representing the instantaneous transmission of the body in the corresponding sectors. The hardness of the fan-shaped X-ray beam is varied periodically in a predetermined manner. Synchronously with the periodic variation of the hardness of the X-ray beam the attenuating elements are oscillated. The oscillation of the attenuating elements is superimposed at each instant on the instantaneous position determined by the signals representing the instantaneous body transmission. The amplitude of the oscillation is less than the height of the slit of the slit diaphragm. The influence on the X-ray beam is most at the instants at which the hardness is greatest.

Abstract: Irradiation equipment comprising a beam duct disposed along the synchrotron radiation beam, and a multistage axial flow turbine installed in the beam duct. The multistage axial flow turbine comprises a plurality of stators and rotors arranged alternately in an axial direction. Each stator has vanes and a beam transmission hole formed through the vane region. Each rotor has vanes and gaps between adjacent vanes. A plurality of beam transmission holes are aligned in a direction of the synchrotron radiation beam, and a plurality of gaps of the rotors are intermittently aligned in the direction of the synchrotron radiation beam, whereby the synchrotron radiation beam can intermittently penetrate through the multistage axial flow turbine through the beam transmission holes and gaps with rotation of the rotor.

Abstract: An X-ray device comprising an X-ray tube (1); a shutter (9) which is movable between an open position (not shown) in which X-rays from the X-ray tube (1) may be directed onto material (8) to be tested and a closed position (shown in FIG. 1) in which the said X-rays are prevented from being so directed; an X-ray detector (4) for detecting fluorescent X-rays emitted by said material (8) when the shutter (9) is open; means (2) movable with the shutter (9) for receiving X-rays from the X-ray tube (1) and for directing fluorescent X-rays onto the X-ray detector (4) when the shutter (9) is closed; and correction means (11-14) connected to said X-ray detector (4) for automatically correcting a change in the X-rays produced by the X-ray tube (1).

Abstract: In a method for slit radiography a fan-shaped X-ray beam scans a body to form an X-ray shadow image. The fan-shaped beam is formed by a number of sectors situated next to each other. For each sector the transmitted X-ray radiation is controlled instantaneously during a scan by means of controllable beam sector modulators. The X-ray radiation is cyclically modulated in a predetermined manner for all the sectors taken together. The controllable beam sector modulators are individually controlled to select cyclically and in synchronism with the predetermined cyclic modulation a part of the X-ray radiation for each sector.

Abstract: A dosimeter for ionizing radiation is of oblong shape. It comprises a gas-filled measuring chamber surrounded by a casing. THe casing is formed of two oblong frames of insulating material that are substantially similar in shape. The two frames are mounted on each other in a gas-tight manner. The anode wires are situated in the plane of separation between the frames and are secured by the frames in contact with each other. At least one of the frames is provided with a cathode over its whole length and parallel to the plane in which the anode wires are situated. Along the edge of the cathode extends a guard electrode which surrounds the cathode with a certain gap. The dosimeter is made of materials that are transparant to the ionizing radiation. It can be used particularly in slit radiography equipment in which the slitwidth can be controlled locally and independently along the length of the slit.