Abstract: A method and device for imaging an object illuminated by an X-ray beam, through a zone plate, is disclosed. A concave mirror with a multilayered film is disposed on a path of the X-ray beam to reflect the same and collect the same onto the object.

Abstract: A high resolution laminography system for the inspection of integrated circuits wherein a beam of highly focused electrons is traced in a circular pattern on a flat target within a vacuum chamber. The target converts the electron beam into X-rays, so that a source of X-rays is produced which rotates in synchronization with a rotating detector assembly. An object is placed within the vacuum chamber, between the X-ray source and the detector so that an X-ray cross sectional image of a cutting plane of the object is produced. A computer and feedback system controls image acquisition and an automated positioning system. The computer system can also operate under program control to automatically analyze data, measure characteristics of the object under inspection, and make decisions regarding the acceptability of the object's quality.

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: An X-ray volume analysis method of crystalline defects of a part (11), comprises the steps of positioning the part in the plane situated at equal distance from the focus of an X-ray source and a focusing plane (14); illuminating the part from a punctual X-ray source (10) by a beam of a large spectral width .DELTA..lambda. and of determined angular opening .DELTA..theta., the opening .DELTA..theta. of the beam being fixed by .DELTA..theta..ltoreq..DELTA..lambda./2d.cos.theta., d being the interreticular distance for the considered reticular planes; orienting the part (11) to obtain the diffraction on a chosen family of reticular planes (30); and collecting and analyzing the X-ray beam near the focusing plane or beyond.

Abstract: Disclosed are a reflection mirror for reflecting a received radiation beam to produce a reflection beam, a reflection device with such a mirror, a scanning system with such a mirror and an exposure apparatus with such a mirror. A radiation beam is inputted to the reflection mirror with an angle of incidence which changes with position on the reflection mirror, wherein the reflection mirror has a multilayered film effective to provide an increased relative reflectivity with respect to a predetermined wavelength of the reflection beam, and wherein a layer of the multilayered film has a thickness which changes with position so as to substantially avoid a shift of the wavelength of the reflection beam dependent upon the angle of incidence.

Abstract: A tomograph makes use of phase information obtainable from a radiation beam having transmitted a to-be-inspected object. In one embodiment, the tomograph has an interferometer for producing interference infringes between a signal beam having transmitted through the object and a reference beam and eventually producing Moire fringes a detector for detecting the Moire fringes, and a signal processing unit for processing outputs of the detector.

Abstract: An x-ray monochromator, wherein a housing supports a plurality of mirrors forming a plurality of opposed mirror faces in parallel with each other and having thereon multilayer coatings, with each of said pairs of mirror faces being provided with identical coatings which are different from the coatings on the other pairs of mirror faces such that each pair of mirror faces has a peak x-ray reflection at a different wavelength regime. The housing is moveable to bring into a polychromatic x-ray beam that pair of mirror faces having the best x-ray reflection for the desired wavelength, with the mirrors being pivotable to move the mirror faces to that angle of incidence at which the peak reflectivity of the desired wavelength x-rays occurs.

Abstract: An x-ray diagnostics installation has a primary radiation diaphragm disposed in the beam path of an x-ray tube, with the x-rays attenuated by an examination subject being processed through an image intensifier video chain, which includes an image memory. The primary radiation diaphragm is provided with sensors which generate an electrical signal corresponding to the position of the individual diaphragm components of the primary radiation diaphragm, these signals being supplied to a processing stage in the image intensifier video chain. The processing stage acts on the data stored in the image memory so that the effect of the diaphragm can be simulated, and included in the displayed image. The processing stage includes a control computer connected to the sensors, and a simulation circuit for simulating the effect of the primary radiation diaphragm.

Abstract: A slit radiography assembly including an X-ray source, and X-ray detector and a slit diaphragm comprised of a plurality of sections juxtaposed in the longitudinal direction of the slit and coacting with controllable attenuation elements wherein: during scanning, a detection assembly includes a plurality of response sections cooperate with the X-ray detector to provide an electric signal representative of the intensity to control the attenuation elements during scanning at initial measuring exposure and subsequent radiographical exposure of the body.

Abstract: An improved apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined first distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals.

Abstract: A monochromatic X-ray radiation source includes an anode for producing X-ray radiation, a target enclosed by the anode for converting X-ray radiation into fluorescence radiation and a screen located between the target and the anode for screen the target from electrons. A higher output of fluorescence radiation is attained in that the screen comprises an element having an atomic number greater than 50, for example, tungsten or tantalum.

Abstract: An X-ray mask structure for X-ray lithography which can be adjusted by applied force to provide variable magnification of a pattern on the mask membrane. The applied force is provided by the heat expansion of a deformable member and the resultant stress on a support ring. A circular patterned mask membrane is supported in a ring composed, for example, of silicon or silicon-pyrex. The support ring contains a concentric aluminum ring having an embedded circular heating element. The heating element causes expansion of the aluminum ring which causes mechanical stress in the support and expansion of the mask membrane. Expansion of the mask membrane results in a corresponding magnification of the pattern thereon.

Abstract: An exposure apparatus for transferring a pattern of an original onto a workpiece, includes a blocking member for defining a rectangular exposure region with respect to at least one of the original and the workpiece, wherein the exposure for the pattern transfer can be effected with the exposure region defined by the blocking member. Plural detection systems detect a positional deviation between the original and the workpiece, each of which is disposed so as to be associated with at least one of four sides of the rectangular exposure region. Plural first movable stages each is provided so as to be associated with at least one of the four sides, and each is adapted to carry thereon one of the detection systems disposed to be associated with a corresponding side. Each first movable stage comprises a single-axis stage movable in a direction parallel to a corresponding side.

Abstract: The focus of a lithotriptor comprising a transducer for generating focused ultrasonic shock waves is adapted for alignment on a concretion or tissue to be destroyed. The transducer is connected to an image-forming diagnostic X-ray system for locating the concretion or tissue, and comprising an X-ray emitter and an image intensifier disposed on a pivotable frame. The transducer is connected to the X-ray emitter, and the X-ray emitter is disposed at the center of the transducer, so that the emission axes of the transducer and the X-ray emitter coincide.

Abstract: An X-ray lithography optical system has an elongated concave scanning mirror spaced a first predetermined distance from a source of X-rays. The mirror has a reflecting surface of part toroidal configuration having a first radius of curvature coincident with that of a torus of which the mirror is part and spaced opposite first and second ends having a second radius of curvature, different from the first radius of curvature, coincident with that of the circle which generates the torus. A photoresist is spaced a second predetermined distance from the mirror and positioned to receive X-rays reflected by the mirror. The second predetermined distance is greater than the first predetermined distance. A mask in proximity with the photoresist permits a predetermined pattern of X-rays to impinge on the photoresist and blocks all other X-rays.

Abstract: A system for locating a region of varying density in biological tissue such as a breast includes a controlled x-ray source for directing x-rays through the breast, a phosphor screen positioned to receive x-rays exiting from the tissue and producing light in response thereto, a cooled, slow scan CCD camera, a variable magnification optical system positioned to receive light emitted by the phosphor screen and directing it to the cooled, slow scan CCD camera, a high resolution monitor, and a control system receiving signals from the cooled, slow scan CCD camera and digitizing the signals to produce digital data representative of the densities of various locations of the tissue.

Abstract: A slit radiography device scans a body under examination with a fan-shaped x-ray beam. A number of absorption elements placed next to each other can be moved into the x-ray beam to a greater or lesser extent in order to influence the x-ray radiation incident on the body per sector of the beam. As seen in the longitudinal direction of the slit the absorption elements are designed such that a certain distance is present between them. As seen in the direction of the radiation beam the thickness of the material of the absorption elements is always the same so that there are no gaps between the elements that the x rays can shine through.

Abstract: An imaging X-ray microscope having an X-ray radiation source, a condenser for condensing X-rays radiated from the X-ray source on an object, an objective for forming an image of the object by the X-rays transmitted through or diffracted by the object, and an X-ray detector for receiving the image formed by the objective, the objective comprising a Schwarzschild optical system in which a concave mirror with an opening in the center thereof and a convex mirror are coaxially arranged in such a manner that the convex mirror opposes to the opening of the concave mirror, the object-side numerical aperture is at least 0.24, and the following condition is satisfied:(N.A.-0.6)/12.ltoreq.(W.sub.2 -W.sub.1)/f.ltoreq.-0.005where N.A. is the object-side numerical aperture of the Schwarzschild optical system, W.sub.1 is the distance from the object to the center of curvature of the concave mirror, W.sub.

Abstract: An X-ray exposure apparatus includes an X-ray source; and a directing optical system for directing an X-ray beam from the X-ray source to a surface to be exposed, the directing optical system incuding a mirror having a reflection surface of a curvature radius R with respect to a predetermined sectional plane, for reflecting the X-ray beam and for expanding the diameter thereof with respect to the sectional plane; wherein the mirror satisfies the following conditions:R=(2d.sub.1 d.sub.2 .sigma.')/{[.DELTA.-(d.sub.1 +d.sub.2).sigma.'].multidot..alpha.}whered.sub.1 : the distance from the emission point of the X-ray source to the center of effective X-ray beam diameter on the reflection surface;d.sub.2 : the distance from the center of effective X-ray beam diameter on the reflection surface to the center of effective X-ray beam diameter on the surface to be exposed;.alpha.

Abstract: In an x-ray tube of the beam deflection type for a radiology apparatus, the stair-steps of the focusing device of the electron beam are extended by metallic deflecting electrodes placed in parallel relation to said stair-steps and electrically insulated from these latter by means of insulating layers. Said electrodes are brought to different potentials, the polarities and values of which depend on the direction and amplitude of deflection to be obtained.

Abstract: An exposure apparatus for exposing a substrate with X-rays is disclosed. The apparatus includes a radiation source for providing X-rays; and a convex mirror for reflecting the X-rays from the radiation source toward the substrate to expose a zone of the substrate with the X-rays; wherein the convex mirror and the substrate are so interrelated that a peak position of intensity distribution of the X-rays upon the zone deviates from the center of the zone.

Abstract: A Compton x-ray backscatter gage apparatus directing x-rays from an isotopic radiation source to a region of interest in a composite structure to monitor structural integrity. The backscattered x-rays from the region of interest are directed by guides in the gage housing to radiation detectors.

Abstract: Accurate and repeatable patient alignment with a charged-particle beam of a radiation beam therapy system, such as a proton beam delivery system, is provided. The patient is immobilized within a form-fit patient pod. Reference radiographs are prepared that are used for repositioning the patient within the pod on subsequent occasions. CT scan data of a particular tissue volume of interest, such as a region of the patient wherein a cancerous tumor is located, is obtained while the patient remains in the pod. The CT scan data is used to prepare a treatment plan for the patient. The treatment plan includes identifying an isocenter within the tissue volume at which the beam is to be directed from a selected angle(s). A computer simulation of the treatment plan may be performed to optimize the treatment plan, i.e., to help identify the number of beams and treatment angles that will best irradiate the cancerous cells.

Abstract: A method and apparatus for increasing the coherence and reducing the emittance of a beam-shaped pulse operates by splitting the pulse into multiple sub-beams, delaying the propagation of the various sub-beams by varying amounts, and then recombining the sub-beams by means of a rotating optical element to form a pulse of longer duration with improved transverse coherence.

Abstract: The ends of a tapered glass capillary are secured in relatively movable mounting blocks for application of axial tension to the capillary. This mounting enables the capillary to be pulled taut so that its axis is straight to facilitate propagation of X-rays. The capillary is coated to provide flexibility and strength. The ends of the capillary extend into their respective mounting blocks, with at least a portion of each end being stripped of the coating material. A bonding material contacts the glass and the coating material and secures both to their corresponding mounting blocks to hold the capillary in place when tension is applied and to provide shear strength for the capillary wall.

Abstract: An apparatus is disclosed for examining containers and/or vehicles at an airport for impermissible contents, such as explosives, weapons, drugs, smuggled goods and the like. To improve the ability to identify such items in the article or vehicle under inspection, an image processor is provided having a computer to which the signals of the radiation detectors are supplied. The computer uses these signals to calculate a radiation silhouette of the articles. A memory is provided in which a reference image of the article is stored. A comparison circuit is supplied with the signals from the computer and from the memory, so that a differential image derived from the calculated radiation silhouette from the computer and from the reference image is displayed on a monitor, connected to the comparison circuit. Differences between the cureent image and the reference image can thereby be easily observed.

Abstract: For performing an X-ray examination wherein a catheter is inserted into a blood vessel of a subject from the brachial region, an X-ray shield is mounted on an arm rest to shield scattered X-rays passed from the subject, to thereby protect operator's hands handling the catheter.

Abstract: A CT apparatus reduces errors in projection data acquired in helical scanning. The imaged object moves concurrently along a translation axis and the x-ray beam is periodically translated with the imaged object so as to subtend a single predetermined volume element during the acquisition of one projection set of data for a first slice. The x-ray beam then returns to its starting position and tracks a second predetermined volume element within a next slice. The x-ray beam may be translated by moving the focal point or a collimator or a combination of both.

Abstract: Background-reducing x-ray multilayer mirror. A multiple-layer "wavetrap" deposited over the surface of a layered, synthetic-microstructure soft x-ray mirror optimized for reflectivity at chosen wavelengths is disclosed for reducing the reflectivity of undesired, longer wavelength incident radiation incident thereon. In three separate mirror designs employing an alternating molybdenum and silicon layered, mirrored structure overlaid by two layers of a molybdenum/silicon pair anti-reflection coating, reflectivities of near normal incidence 133, 171, and 186 .ANG. wavelengths have been optimized, while that at 304 .ANG. has been minimized. The optimization process involves the choice of materials, the composition of the layer/pairs as well as the number thereof, and the distance therebetween for the mirror, and the simultaneous choice of materials, the composition of the layer/pairs, and their number and distance for the "wavetrap.

Abstract: Disclosed is a radiology system of the mammograph type in which there is provision for a radiation controller. The invention lies in the fact that the input aperture of the detector is masked by a belt that absorbs the X-radiation except at zones, the variable dimensions of which are designed to get adapted to the different shapes of breasts. The belt is driven by a motor 24 and stops at the practitioner's command so that the appropriate zone is in correspondence with the input aperture of the detector 22.

Abstract: An X-ray image pick-up method causes X-rays from an X-ray source to be irradiated on an object for picking up its image as passed through a filter capable of restricting any fluctuation of the effective X-ray energy within .+-.10%, and then the X-rays thus penetrated through the object to be picked up by an image pick-up means. Radiation dose with respect to the object and eventually to operators is thereby minimized, while the image pick-up can be realized with a high resolution.

Abstract: An equalization radiography system automatically identifies the lung field in a pre-scan and then carries out an imaging scan in which it equalizes the X-ray exposure but only outside the lung field.

Abstract: An equalization radiography system using specially shaped and arranged modulator pins which reduce artifacts by effectively smoothing variations in attenuation as between adjacent pins.

Abstract: The invention relates to an X-ray tube used to obtain radiological images in which sharpness and contrast are improved. To this end, the X-ray tube has an anode consisting, at least partially, of a massive layer made of an X-ray emitting material in which at least one hollow part demarcates a surface exposed to a beam of electrons.

Abstract: In a lithotriptor a shock wave transducer is provided with a focussing cup and with a forward section containing a coupling medium shut off by means of a diaphragm for application to a patient's body. In the wall of the cup there is mounted a locating system comprising an x-ray emitter the outlet of which is located in the coupling medium. The outlet is closed by means of a balloon which can be filled with gas and which can be evacuated. When the balloon is filled with gas, it expands in the direction of radiation of the x-rays up to or almost up to the diaphragm of the forward section.

Abstract: A body is scanned by a fan-shaped X-ray beam for an X-ray shadow image. Per sector of the fan-shaped X-ray beam detection means deliver a signal which is a measure of the quantity of X-ray radiation instantaneously transmitted in the respective sector through the body. An attenuation device operates in conjunction with a slit-type diaphragm and regulates the quantity of X-ray radiation transmitted under the control of control signals per sector of the fan-shaped X-ray beam. The control signals are formed on the basis of the signals from the detection means. The attenuation device comprises one or more elastic X-ray radiation absorbing strips extending essentially parallel to the slit-type diaphragm. The attenuation device comprises controllable drive members to bring the strip or strips to an undulated state.

Abstract: In general, it can be difficult and time consuming to mount X-ray shields or filters on an X-ray machine. An even more serious difficulty is that of effectively masking all but a specific area. A relatively effective X-ray shielding support, which can be adjusted in any direction to mask all but a specific area includes an apertured base plate for mounting on the machine to define a frame around the collimator aperture of the machine, a variety of spacers for mounting on the base plate, and filter holders for mounting on at least one of the base plate and spacers. The spacers and filter holders are magnetic to make interconnection of the elements quick and easy.

Abstract: A method and device for producing flux equalized x-ray images for medical radiography through the use of a scanning fan shaped x-ray beam and a feedback control system which regulates the beam intensity at a multiple number of points along the fan beam to compensate for the x-ray attenuation variations of the patient.

Abstract: Disclosed is a radiology system of the mammography type wherein there is provision for a radiation controller having a detector of X-radiation having gone through the breast to be observed, of the type having a converter of X-radiation into photon radiation and a photomultiplier tube for the amplifications of photons emitted by the converter. The invention lies in the fact that the converter is masked by a belt opaque to the photon radiation except in the zones for which variable dimensions are planned so as to get adapted to the different shapes of breasts. The belt is driven by a motor which is turned on and off at the practitioner's command, so that the appropriate zone is in correspondence with the converter.

Abstract: Radiation of specific material within a subject is accomplished by use of a beam of x-radiation modulated at a microwave frequency. The beam with its modulation is directed at the subject wherein the material interacts with the beam to extract a portion of the radiant energy carried by the beam. In the interaction, an electric field at the modulating frequency appears at the material. By selecting the modulated frequency equal to a resonant interactive microwave frequency of the material, a photon at the microwave frequency is absorbed by the material to alter its physical and chemical properties. By way of example, the material may be an oncogene or virus having a macromolecule and constituting a malignancy within a living subject. Absorption of the modulated radiation selectively destroys the malignancy. The klystron is disposed along the path of an electron beam in an x-ray source for modulating the electron beam and the resulting x-ray beam.

Abstract: Optical elements for radiation comprising a graphite film obtained from a film of a polymer such as polyphenylene oxadiazole, polybenzothiazole, polybenzobisthiazole, polybenzooxazole, polybenzobisoxazole, polypyromellitimide, polyphenylene isophthalamide, polyphenylene benzoimidazole, polyphenylene benzobisimidazole, polythiazole or poly-p-phenylene-vinylene. The graphite film is obtained by pyrolysis of the polymer film at 2800.degree. C. or higher at a pressure of not lower than 4 kg/cm.sup.2 in vacuum or in an inert gas. Alternatively, the element may be made of a graphite film obtained from the polymers mentioned above and intercalated with a metal halide. The intercalated films are readily bonded by pressing in the form of a thick sheet or block. Still alternatively, the graphite films and the intercalated films may be superposed alternately and bonded by pressing, or the intercalated films may be sandwiched between the graphite films and bonded together to form a thick sheet or block.

Abstract: An exposure compensation apparatus for use in a radiographic equipment to modulate local intensity of radiation. The exposure compensation apparatus comprises a detecting means to detect transmittance of radiation at a location of a radiated object, right-left reversion means to reverse a location arrangement of the transmittance data on a line of a predetermined direction, an averaging means to average a pair of the original and reversed transmittance data of a location to acquire an averaged transmittance, and a local intensity control means to control a local intensity compensation means of the radiographic equipment.

Abstract: Method and apparatus for producing sharp, chromatic, magnified images of X-ray emitting objects, are provided. The apparatus, which constitutes an X-ray microscope or telescope, comprises a connected collection of Bragg reflecting planes, comprised of either a bent crystal or a synthetic multilayer structure, disposed on and adjacent to a locus determined by a spherical surface. The individual Bragg planes are spatially oriented to Bragg reflect radiation from the object location toward the image location. This is accomplished by making the Bragg planes spatially coincident with the surfaces of either a nested series of prolate ellipsoids of revolution, or a nested series of spheres. The spacing between the Bragg reflecting planes can be tailored to control the wavelengths and the amount of the X-radiation that is Bragg reflected to form the X-ray image.

Abstract: A transmission grating in which the vertical supports are equidistantly sed from each other in each of the horizontal rows but have their positions relative to each vertical support in all of the other rows determined by a pseudo-random integer of the spacings between the grating wires. As a result, all of the artifacts produced by the vertical supports are eliminated from the diffraction plane.

Abstract: An X-ray radiography system comprising divided fan beam scanning device, feed-back the beam regulator and a silver halide photosensitive material having a covering power not less than 45 which is capable to diagnose wide range of photodensity area at one time exposure for minimizing the radiation dose is disclosed.

Abstract: An optical system for X rays having a multilayer reflecting mirror which has high reflectances for X rays of different wavelengths. One type of multilayer reflecting mirror is such that the mirror surface of the multilayer reflecting mirror is divided into a plurality of regions, and the regions are provided with multilayers which are such that the reflectance of each multilayer is maximum for X rays of a corresponding wavelength. Another type of multilayer reflecting mirror has a substrate and a plurality of multilayer laid on the substrate, wherein the wavelength of X rays to be reflected with a maximum reflectance varies from multilayer to multilayer. The optical system for X rays according to the present invention is a focusing optical system having a plurality of such multilayer reflecting mirrors and can obtain object images by using X rays of a plurality of wavelengths.

Abstract: A variable magnification variable dispersion glancing incidence x-ray spectroscopic telescope capable of multiple high spatial revolution imaging at precise spectral lines of solar and stellar x-ray and extreme ultraviolet radiation sources includes a pirmary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable carries each providing a different magnification are positioned behind the primary focus at an inclination to the optical axis, each carrier carrying a series of ellipsoidal diffraction grating mirrors each having a concave surface on which the gratings are ruled and coated with a mutlilayer coating to reflect by diffraction a different desired wavelength. The diffraction grating mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus.

Abstract: A device for the amplification of X-ray intensity: X-rays originating from a conventional source are made to reflect several times onto a metallic surface. At the moment of each reflection or the like the incident X-rays provoke emission of other X-rays from the reflective surface. The X-rays emitted during each reflection reinforce the intensity of the reflected ray, amplifying thus the intensity. To obtain this, the metallic reflective surface is maintained in an excited state suitable for X-ray emission. The device is made up of two concentric metal rings, to which is applied a high voltage. In the space between the metal rings an exciting gas is introduced, that, due to the strong potential difference applied, excites the metal surfaces of the rings.

Abstract: A simulation/generation/verification system for blocker patterns and blockers for use in radiation therapy comprises a fluoroscopic simulator apparatus, a computer system for acquisition and processing of fluoroscopic images, a manual input device for superposing blocker pattern outlines onto such images, display and storage devices for such images, apparatus for automatic cutting of blocker contour templates, blocker patterns and blockers, and apparatus for verification thereof. The system also facilitates acquisition of compensator contours and generation of corresponding compensator filters for incorporation with blockers. The system facilitates simulation, generation, and verification of blocker patterns or blockers per se in one substantially continuous procedure that minimizes intervening manual steps, while a patient is aligned within the system during an uninterrupted session.

Abstract: A .gamma.-ray detector that comprises a dislocation-free single crystal. Typical crystals include silicon and germanium, for example. The crystal is surrounded by an active shield that functions as an anticoincidence counter and a .gamma.-ray detector is disposed adjacent the crystal in order to detect received -65 -rays. The .gamma.-ray detector comprises an imaging proportional counter, scintillation counter, or a .gamma.-ray detecting charge coupled device, for example. The .gamma.-ray detector of the present invention is based on the Bormann effect, which is the anomalous transmission of .gamma.-rays through dislocation free single crystals at the Bragg angle. For extended sources, data processing is provided to separate the directional and wavelength dependence of the intensity variation. The .gamma.-ray detector has angular resolution of at least one arc second and may have an effective aperture of several square meters.