Abstract: A radiation tube includes a cathode unit including an electron source, and an anode unit including a target and a shield member arranged around the target. The target is to be irradiated with electrons emitted from the electron source to emit radiation. The cathode unit and the anode unit are joined to each other via a plurality of spacers.

Abstract: An x-ray tube comprising an anode and a cathode disposed at opposing ends of an electrically insulative cylinder. The x-ray tube includes an operating range of 15 kilovolts to 40 kilovolts between the cathode and the anode. The x-ray tube has an overall diameter, defined as a largest diameter of the x-ray tube anode, cathode, and insulative cylinder, of less than 0.6 inches. A direct line of sight exists between all points on an electron emitter at the cathode to a target at the anode.

Abstract: Provided is a field emission X-ray tube. The field emission X-ray tube includes a cathode electrode provided to one end of a vacuum vessel and including a field emission emitter, an anode electrode provided to the other end of the vacuum vessel in an extending direction of the vacuum vessel, and a gate electrode provided on an outer surface of the vacuum vessel adjacent to the cathode electrode.

Abstract: An X-ray tube assembly is provided including an emitter configured to emit an electron beam, an emitter focusing electrode, an extraction electrode, and a downstream focusing electrode. The emitter focusing electrode is disposed proximate to the emitter and outward of the emitter in an axial direction. The extraction electrode is disposed downstream of the emitter and the emitter focusing electrode. The extraction electrode has a negative bias voltage setting at which the extraction electrode has a negative bias voltage with respect to the emitter. The downstream focusing electrode is disposed downstream of the extraction electrode, and has a positive bias voltage with respect to the emitter. When the extraction electrode is at the negative bias voltage setting, the electron beam is emitted from an emission area that is smaller than a maximum emission area from which electrons may be emitted.

Abstract: The present invention relates to the generation of multiple X-ray energies in an X-ray tube. In order to provide an X-ray tube capable of generating multiple-energy X-ray radiation with a minimized design setup and an improved switching capacity, a multiple-energy X-ray tube (10) comprises a cathode (12), an anode (14) and an electron-braking device (16). The anode comprises a target surface (18) provided for generating X-rays as a result of impinging electrons. The cathode is provided for emitting electrons (20, 144, 148, 150) towards the anode to impinge on the target surface of the anode. The electron-braking device is intermittently arrangeable in a pathway (22, 144, 148, 150) of the electrons from the cathode to the anode and configured to slow at least a part of the electrons of the electron beam such that the energy of re-emitted electrons is lower than the energy of arriving electrons.

Abstract: A radiation generator includes: a radiation tube configured to generate radiation by emitting electrons from a cathode through a grid to a target; a grid-voltage generating unit configured to apply an extraction voltage to the grid in response to an external request for radiation output; a cut-off voltage generating unit configured to generate a cut-off voltage applied to the grid so as to lower the potential of the grid relative to the potential of the cathode when there is no external request for the radiation output; and a detection unit configured to detect a decrease in the cut-off voltage, wherein the target is not irradiated by the electrons when the decrease in the cut-off voltage is detected.

Abstract: The X-ray generating apparatus 100 applies an electron beam e1 onto a target 150 to generate X-rays x1, and includes a permanent magnet lens 120 configured to focus the electron beam e1, a correction coil 130 provided on a side of the electron beam e1 with respect to the permanent magnet lens 120 and configured to correct a focus position formed by the permanent magnet lens 120 in a traveling direction of the electron beam e1, and a target 150 onto which the focused electron beam is applied. Accordingly, the apparatus configuration can be extremely compact and lightweight in comparison with general apparatuses. Furthermore, by the correction coil 130, the intensity of the magnetic field can be finely adjusted and the focus position in the traveling direction of the electron beam e1 can be finely adjusted.

Abstract: An X-ray generating device (10) is provided with an electron gun (12) that generates an electron beam, a linear accelerator (14) that accelerates, by means of microwaves, the electron beam generated by the electron gun (12), an X-ray target (16) that generates X-rays by being irradiated with the electron beam accelerated by the linear accelerator (14), a microwave generating device that generates microwaves to be introduced into the linear accelerator (14), and a pulse modulator that controls the microwave generating device so as to change the power of the microwaves. Because the linear accelerator (14) includes a plurality of buncher cavities (40), even if there are electrons that are shifted out of the acceleration phase when the power of the microwaves is decreased, these electrons can be accelerated in the acceleration phase of the next time period; therefore, a decrease in the intensity of an electron beam to be emitted is suppressed even if the power of the microwaves is decreased.

Abstract: The invention comprises an X-ray method and apparatus used in conjunction with charged particle or proton beam radiation therapy of cancerous tumors. The system uses an X-ray beam that lies in substantially the same path as a proton beam path of a particle beam cancer therapy system. The system creates an electron beam that strikes an X-ray generation source where the X-ray generation source is located proximate to the proton beam path. By generating the X-rays near the proton beam path, an X-ray path that is essentially the proton beam path is created. Using the generated X-rays, the system collects X-ray images of a localized body tissue region about a cancerous tumor. The generated image is usable for: fine tuning body alignment relative to the proton beam path, to control the proton beam path to accurately and precisely target the tumor, and/or in system verification and validation.

Abstract: An X-ray tube is provided. The X-ray tube includes a cathode electrode which is disposed in one end of a vacuum container and includes an emitter emitting an electron; a gate electrode which is disposed in the vacuum container to be adjacent to the cathode electrode; an anode electrode which is disposed in the vacuum container of the other end of a direction in which the vacuum container extends and inclines with respect to the cathode electrode; and a focusing electrode which is disposed in the vacuum container along an inner circumference surface of the vacuum container between the gate electrode and the anode electrode. The focusing electrode has an opening of which a plan cross section has a maximum width and a minimum width different from each other.

Abstract: An x-ray tube is presented. One embodiment of the x-ray tube includes a cathode unit configured to emit electrons. The x-ray tube further includes an anode unit positioned to receive the emitted electrons, wherein the anode unit includes a base having a target surface configured to generate x-rays when the emitted electrons impinge on the target surface. Also, the anode unit includes a first shielding unit enclosing the base to attenuate at least a first portion of the generated x-rays within the anode unit.

Abstract: An apparatus for modifying an aspect ratio of an electron beam to form a focal spot having a desired size and aspect ratio on a target anode is disclosed. The apparatus includes an emitter element configured to generate an electron beam having a first aspect ratio shape and an extraction electrode positioned adjacent to the emitter element to extract the electron beam out therefrom, the extraction electrode including an opening therethrough. The apparatus also includes at least one shaping electrode positioned to receive the electron beam after passing through the extraction electrode, the shaping electrode defining a non-circular aperture therein and being configured to provide at least one of shaping and focusing of the electron beam to have a second aspect ratio shape different from the first aspect ratio shape so as to form a focal spot having a desired size and aspect ratio on a target anode.

Abstract: The present embodiments relate to off-focal X-ray radiation attenuation within X-ray tubes, for example X-ray tubes used in CT imaging. In one embodiment, an X-ray tube for off-focal X-ray radiation attenuation is provided. The X-ray tube includes a cathode, a target, and a magnetic focal spot control unit having at least one electromagnet encased in a resin loaded with X-ray attenuating material.

Abstract: An adjusting method of an X-ray apparatus has a reflection structure, wherein assuming that one end plane of the reflection structure is an inlet port of the X-ray and the other end plane is an outlet port of the X-ray, a pitch of the reflection substrates at the outlet port is wider than that at the inlet port. When the X-ray source exists at a position where a glancing angle at the time when the X-ray enters the inlet port exceeds a critical angle, an intensity of the X-ray emitted from each passage is detected. On the basis of the detected X-ray intensity, a relative position of the X-ray source and the reflection structure is adjusted.

Abstract: An apparatus is provided for a micro focus X-ray tube for a high-resolution X-ray comprising a housing, an electron beam source for generating an electron beam and a focusing lens for focusing the electron beam on a target. The X-ray tube comprises a substantially rotationally symmetrical, ring-shaped cooling chamber configured to circulate a liquid cooling medium.

Abstract: X-ray tube aperture body with shielded vacuum wall. In one example embodiment, an aperture body for use in an x-ray tube having an anode and a cathode includes an electron shield and a vacuum wall. The electron shield is configured to intercept backscattered electrons from the anode. The vacuum wall is separated by a gap from the electron shield and is shielded from the backscattered electrons by the electron shield. The aperture body also includes an electron shield aperture defined in the electron shield and a vacuum wall aperture defined in the vacuum wall through which electrons may pass between the cathode and the anode.

Abstract: A method for controlling emission of a beam of electrons in an X-ray imaging tube. The X-ray imaging tube has an anode and a cathode. The method comprises a step in which at least one emission device included in the cathode emits an accelerated incident beam of electrons onto an impact focal spot on the anode to generate X-rays. An emission device is associated firstly with an assembly of polarizing plates and secondly with a focusing cup. An electric generator simultaneously applies a beam focusing voltage to the assembly and/or to the cup to control a characteristic dimension of the focal spot, and a cut-off voltage to the cup to control the emission of the beam by the device. The invention also concerns a corresponding cathode, tube and imaging system.

Abstract: The present invention refers to an X-ray tube of the rotary-anode type which comprises at least one temporarily negatively biased auxiliary grid electrode (119) with an aperture through which an electron beam (115) emitted by a tube cathode's thermoionic electron emitter (111) can pass. As an alternative thereto, the auxiliary grid electrode (119) may also be positively biased so as to enhance electron emission from a thermoionic electron emitter (111). The auxiliary grid electrode may thereby be connected to a supply voltage UAUX of a controllable voltage supply unit by means of a feedthrough cable (120) serving as a feeding line for providing the main control grid (112) with a grid supply voltage UG.

Abstract: In an X-ray generator which includes an electron beam generating unit which has a plurality of electron emitters and generates an electron beam corresponding to driven electron emitters, and a target electrode which generates X-rays with the irradiation position of an electron beam generated by the electron beam generating unit being an X-ray focus, the X-ray focus shape formed by a set of X-ray focuses on the target electrode is controlled by individually controlling driving of the plurality of electron emitters.

Abstract: An x-ray tube comprising an anode and a cathode disposed at opposing ends of an electrically insulative cylinder. The x-ray tube includes an operating range of 15 kilovolts to 40 kilovolts between the cathode and the anode. The x-ray tube has an overall diameter, defined as a largest diameter of the x-ray tube anode, cathode, and insulative cylinder, of less than 0.6 inches. A direct line of sight exists between all points on an electron emitter at the cathode to a target at the anode.

Abstract: An indirectly heated cathode assembly is presented. The indirectly heated cathode assembly includes at least one electron source for generating a first electron beam, an emitter for producing a second electron beam when heated by the first electron beam and a focusing electrode for controlling, and directing the first electron beam towards the emitter.

Abstract: A cathode assembly for an x-ray tube. In one example embodiment, a cathode assembly includes a cathode head, a filament, and first and second focusing tabs. The cathode head defines a recess having first and second open ends, a slot within the recess, and first and second tab stops within the recess. The filament is positioned within the slot. The first focusing tab is positioned in the first open end of the recess abutting the first tab stop. The second focusing tab is positioned in the second open end of the recess abutting the second tab stop.

Abstract: An X-ray generator and an X-ray photographing apparatus including the X-ray generator generate characteristic X-rays. The X-ray generator includes an electron beam emission unit that emits electron beams; an electron beam guide unit, in which the electron beam emission unit is disposed, for condensing the electron beams and causing the electron beams to travel in a predetermined direction; and a target unit disposed to face the electron beam guide unit, and discharging X-rays when the electron beams collide with the target unit.

Abstract: An injector for an X-ray tube is presented. The injector includes an emitter to emit an electron beam, at least one focusing electrode disposed around the emitter, wherein the at least one focusing electrode focuses the electron beam and at least one extraction electrode maintained at a positive bias voltage with respect to the emitter, wherein the at least one extraction electrode controls an intensity of the electron beam.

Abstract: An x-ray tube assembly includes a vacuum enclosure that has a cathode portion, a target portion, and a throat portion. The throat portion includes a metal bellows. An upstream end of the throat portion is coupled to the cathode portion and a downstream end of the throat portion is coupled to the target portion. The x-ray tube assembly also includes a target positioned within the target portion of the vacuum enclosure, and a cathode positioned within the cathode portion of the vacuum enclosure. The cathode is configured to emit a stream of electrons through the throat portion toward the target.

Abstract: An electromagnetic wave having a phase velocity and an amplitude is provided by an electromagnetic wave source to a traveling wave linear accelerator. The traveling wave linear accelerator generates a first output of electrons having a first energy by accelerating an electron beam using the electromagnetic wave. The first output of electrons can be contacted with a target to provide a first beam of x-rays. The electromagnetic wave can be modified by adjusting its amplitude and the phase velocity. The traveling wave linear accelerator then generates a second output of electrons having a second energy by accelerating an electron beam using the modified electromagnetic wave. The second output of electrons can be contacted with a target to provide a second beam of x-rays. A frequency controller can monitor the phase shift of the electromagnetic wave from the input to the output ends of the accelerator and can correct the phase shift of the electromagnetic wave based on the measured phase shift.

Abstract: An x-ray tube has an anode and a thermionic emitter with multiple emitter regions spaced from one another that generate, between the emitter and the anode, an electron beam composed of multiple partial beams generated by the respective emitter regions. Between the emitter and the anode is at least one control electrode arrangement that generates a variable electrical field and that has a number of passages to control the respective partial beams. Thus control electrode arrangement has a number of control electrode layers. The individual emitter regions and the control electrodes are arranged and controlled relative to one another to cause substantially the entirety of each partial beam generated by the respective emitter regions to proceed through a passage respectively associated with that partial beam.

Abstract: A device to control an electron beam for the generation of x-ray radiation, has an electron emitter to generate an electron beam, to which emitter an emitter voltage can be applied, a diaphragm, at least two control elements associated with the diaphragm to affect the electron beam, and switching arrangement with which at least two different electrical voltages can be applied to the at least two control elements. The same electrical voltage is applied to each of the at least two control elements. Upon switching the voltage, an electrical circuit that delays the setting of the respective voltage at the one control element is associated with the connection line of the one control element with the switching arrangement to switch over the voltage. The invention moreover concerns an operating method for the device and an x-ray tube provided with the device.

Abstract: In one embodiment, an X-ray tube is provided. The X-ray tube comprises at least one thermionic cathode configured to generate an electron beam, a target assembly configured to generate X-rays when impinged with the electron beam emitted from the thermionic cathode, a high voltage supply unit for establishing an output voltage across the thermionic cathode and the target assembly for establishing an accelerating electric field between the thermionic cathode and the target assembly and a mesh grid disposed between the thermionic cathode and the target assembly, the mesh grid configured to operate at a voltage so as to lower the electric field applied at the surface of the thermionic cathode. Further, the voltage at the mesh grid is negatively biased with respect to the voltage at the thermionic cathode.

Abstract: An x-ray tube has an evacuated, rotatable housing in which are arranged a cathode designed to emit an electron beam and an anode interacting with this cathode, and two quadrupole magnet systems arranged outside of the housing and spaced apart from one another that are provided to influence the electron beam.

Abstract: A microminiature X-ray tube with a triode structure using a nano emitter is provided, which can increase a field emission region as much as possible by means of nano emitters fine-patterned in a cathode to not only increase an emission current per unit area as much as possible but secure high electrical characteristics, reliability, and structural stability by means of a cover and a bonding material. In addition, gate holes having a macro structure can be formed in the gate to promote electron beam focusing by means of the gate without using a separate focusing electrode and to prevent a leakage current from occurring on the gate. Further, an auxiliary electrode can be formed on a top or an inner surface of a cover applied for structural stability to further promote the electron beam focusing and to control the output amounts per individual X-ray tubes output.

Abstract: An x-ray source is described. During operation of the x-ray source, an electron source emits a beam of electrons. This beam of electrons is focused to a spot on a target by a magnetic focusing lens. In response to receiving the beam of focused electrons, the target provides a transmission source of x-rays. Moreover, a repositioning mechanism selectively repositions the beam of focused electrons to different locations on a surface of the target based on a feedback parameter associated with operation of the x-ray source. This feedback parameter may be based on: an intensity of the x-rays output by the x-ray source; a position of the x-rays output by the x-ray source; an elapsed time during operation of the x-ray source; a cross-sectional shape of the x-rays output by the x-ray source; and/or a spot size of the x-rays output by the x-ray source.

Abstract: During operation of an x-ray source, an electron source emits a beam of electrons. Moreover, a repositioning mechanism selectively repositions the beam of electrons on a surface of a target based on a feedback parameter, where a location of the beam of electrons on the surface of the target defines a spot size of x-rays output by the x-ray source. In response to receiving the beam of electrons, the target provides a transmission source of the x-rays. Furthermore, a beam-parameter detector provides the feedback parameter based on a physical characteristic associated with the beam of electrons and/or the x-rays output by the x-ray source. This physical characteristic may include: at least a portion of an optical spectrum emitted by the target, secondary electrons emitted by the target based on a cross-sectional shape of the beam of electrons; an intensity of the x-rays output by the target; and/or a current from the target.

Abstract: An x-ray source is described. This x-ray source includes an electron source with a refractory binary compound having a melting temperature greater than that of tungsten. For example, the refractory binary compound may include: hafnium carbide, zirconium carbide, tantalum carbide, lanthanum hexaboride and/or compounds that include two or more of these elements.

Abstract: The present invention relates to X-ray generating technology in general. Providing X-radiation having multiple photon energies may help differentiating tissue structures when generating X-ray images. Consequently, an X-ray generating device that allows the switching of a potential of an electron collecting element versus an electron emitting element for providing different energy modes is presented. According to the present invention, an X-ray generating device is provided, comprising an electron emitting element (16) and electron collecting element (20). The electron emitting element (16) and the electron collecting element (20) are operatively coupled for the generation of X-radiation (14). A potential is arranged between the electron emitting element (16) and the electron collecting element (20) for acceleration of electrons from the electron emitting element 16 to the electron collecting element (20), the electrons constituting an electron beam (7).

Abstract: An x-ray source is described. During operation of the x-ray source, an electron source emits a beam of electrons. This beam of electrons is focused to a spot on a target by a magnetic focusing lens. In particular, the magnetic focusing lens includes an immersion lens in which a peak in a magnitude of an associated magnetic field occurs proximate to a plane of the target. Moreover, in response to receiving the beam of focused electrons, the target provides a transmission source of x-rays.

Abstract: An apparatus and method for an electron beam manipulation coil for an x-ray generation system includes the use of a control circuit. The control circuit includes a first low voltage source, a second low voltage source, and a first switching device coupled in series with the first low voltage source and configured to create a first current path with the first low voltage source when in a closed position. The control circuit also includes a second switching device coupled in series with the second low voltage source and configured to create a second current path with the second low voltage source when in a closed position and a capacitor coupled in parallel with an electron beam manipulation coil and positioned along the first and second current paths.

Abstract: A super miniature X-ray tube using the nano material field emitter includes a tip-tip-type cathode electrode having the nano material field emitter formed on one end with a planar section thereof to generate an electron beam, a gate electrode formed in a hollow cylindrical shape and surrounding an outer circumference of the cathode electrode, the gate electrode having a tapered portion formed on one end and inclined from inside to outside, the gate electrode receiving a voltage for generating the electron beam, a high voltage insulating portion formed in a hollow cylindrical shape and surrounding an outer circumference of the gate electrode, a anode electrode formed at a predetermined distance from one end of the high voltage insulating portion and receiving an acceleration voltage to accelerate an electron beam generated at the cathode electrode, and an electric field adjusting electrode formed between the high voltage insulating portion and the anode electrode to vary a pattern of an acceleration electric f

Abstract: An electron beam generator includes a cathode electrode; and a first insulating layer, a gate, a second insulating layer and a focusing gate sequentially on the cathode electrode. The cathode electrode, the first insulating layer, the gate, the second insulating layer and the focusing gate are individually separable from each other and combinable with each other.

Abstract: A radiation source for a radiation-based image acquisition device has an electron emitter to generate a focal spot for x-ray generation at a rotating anode. An arrangement is provided to generate an asymmetrical power input profile of the focal spot parallel to the movement direction of the rotating anode.

Abstract: An electromagnetic wave having a phase velocity and an amplitude is provided by an electromagnetic wave source to a traveling wave linear accelerator. The traveling wave linear accelerator generates a first output of electrons having a first energy by accelerating an electron beam using the electromagnetic wave. The first output of electrons can be contacted with a target to provide a first beam of x-rays. The electromagnetic wave can be modified by adjusting its amplitude and the phase velocity. The traveling wave linear accelerator then generates a second output of electrons having a second energy by accelerating an electron beam using the modified electromagnetic wave. The second output of electrons can be contacted with a target to provide a second beam of x-rays. A frequency controller can monitor the phase shift of the electromagnetic wave from the input to the output ends of the accelerator and can correct the phase shift of the electromagnetic wave based on the measured phase shift.

Abstract: Systems and methods are provided for field emission device. An array of carbon nanotubes is arranged in a variable height distribution over a cathode substrate. An anode is provided to accelerate the emitted electrons toward an x-ray plate. Voltage is supplied across the array of carbon nanotubes to cause emission of electrons. The pointed height distribution may be linear or parabolic, and a peak height of the variable height distribution may occur in a center of the array. A side gate may also be provided adjacent the array of carbon nanotubes to provide improved electron emission and focusing control.

Abstract: The system uses an X-ray imaging system having an elongated lifetime. Further, the system uses an X-ray beam that lies in substantially the same path as a charged particle beam path of a particle beam cancer therapy system. The system creates an electron beam that strikes an X-ray generation source located proximate to the charged particle beam path. By generating the X-rays near the charged particle beam path, an X-ray path running collinear, in parallel with, and/or substantially in contact with the charged particle beam path is created. The system then collects X-ray images of localized body tissue region about a cancerous tumor. Since, the X-ray path is essentially the charged particle beam path, the generated image is usable for precisely target the tumor with a charged particle beam.

Abstract: Conventionally, the magnetic field generator was arranged perpendicularly to the axis of the electron beam. The magnetic field generator of this invention is arranged so as to be inclined relative to the plane perpendicular to the axis of the electron beam. Specifically, the magnetic field generator is arranged so as to be inclined relative to the plane perpendicular to the axis of the electron beam within the range in the cathode side from the focused and deflected electron beam. Inclination up to the anode side opposite to the cathode side will lead to a possibility of increasing the reduced X-ray source diameter. Thus, arranging the magnetic field generator so as to be inclined within the range in the cathode side from the electron beam may reduce the X-ray source diameter.

Abstract: According to the X-ray generating apparatus of this invention, a potential corresponding to that of a housing is applied to a first electrode, closest to a cathode, of at least two intermediate electrodes arranged between the cathode and a target. Therefore, even if the first electrode with an increased thermal capacity contacts the housing, the function of the X-ray generating apparatus will never be impaired. As a result, the first electrode is not easily restricted by structure, so that the first electrode may be enlarged as a measure for heat radiation, or that the first electrode may be placed in contact with the housing. The first electrode contacting the housing determines a positional relationship of the electron gun and housing to facilitate assembly of the X-ray generating apparatus. Further, all the potentials of the cathode, intermediate electrodes (e.g.

Abstract: Provided is a field emission X-ray tube. The field emission X-ray tube includes a cathode electrode provided to one end of a vacuum vessel and including a field emission emitter, an anode electrode provided to the other end of the vacuum vessel in an extending direction of the vacuum vessel, and a gate electrode provided on an outer surface of the vacuum vessel adjacent to the cathode electrode.

Abstract: An x-ray tube includes a casing having a cathode and an anode enclosed therein, and a separator attached to an inner wall of the casing and having a conductance limiter therein, the separator positioned to separate the anode from the cathode.

Abstract: An x-ray tube assembly includes a vacuum enclosure that includes a cathode portion, a target portion, and a throat portion having a plurality of recesses formed therein to break up eddy currents generated in the throat portion. The throat portion has an upstream end coupled to the cathode portion and a downstream end coupled to the target portion. The x-ray tube assembly also includes a target positioned within the target portion of the vacuum enclosure, and a cathode positioned within the cathode portion of the vacuum enclosure. The cathode is configured to emit a stream of electrons through the throat portion toward the target.

Abstract: An x-ray tube assembly includes a vacuum enclosure that has a cathode portion, a target portion, and a throat portion. The throat portion includes a metal bellows. An upstream end of the throat portion is coupled to the cathode portion and a downstream end of the throat portion is coupled to the target portion. The x-ray tube assembly also includes a target positioned within the target portion of the vacuum enclosure, and a cathode positioned within the cathode portion of the vacuum enclosure. The cathode is configured to emit a stream of electrons through the throat portion toward the target.

Abstract: A method for generating an X-ray includes the steps of: disposing at least a target in a chamber; irradiating an electron beam onto the target from an electron beam source disposed in or outside the chamber so as to satisfy a relation of ??60 degrees if an incident angle of the electron beam is defined as “?”; and generating and taking an X-ray out of the target so as to satisfy a relation of ?30 degrees?????60 degrees if an output angle of the X-ray relative to a surface of the target is defined as “?”.