Abstract: Described herein, are methods for providing a protective coating to a storage container for storing nuclear material, the method comprising depositing nickel particles on at least one surface of the substrate to produce the protective coating, wherein the nickel particles are deposited by cold spraying a composition comprising nickel particles and a carrier gas comprising nitrogen. In one aspect, the carrier gas consists essentially or consists only of nitrogen. The methods do not require pretreatment or modification of the nickel particles prior to cold spraying, which makes the methods described herein economically practical. The coatings produced by the methods described herein possess several advantageous properties including, but not limited to, high adhesion strength to the storage system and low porosity. The coatings produced by the methods described herein are effective against chemical attack such as, for example, CISCC.

Abstract: A charged particle emission control technique where slow extraction of a charged particle beam from a synchrotron can be stably performed even in a state where beam adjustment has not been performed or completed. A charged particle emission control device includes a first receiver configured to receive a first detection signal obtained by detecting a current value of charged particles orbiting in a synchrotron; an arithmetic processor configured to time-differentiate the first detection signal and output a beam-intensity equivalent-value; and an emission controller configured to output a control signal for emitting a charged particle beam from the synchrotron to a beam transport system in such a manner that the beam intensity-equivalent value matches a target value.

Abstract: An infrared emitter with a glass lid for emitting infrared radiation comprises a package enclosing a cavity, wherein a first part is transparent for infrared radiation and a second part comprises a glass material and a heating structure configured for emitting the infrared radiation, wherein the heating structure is arranged in the cavity between the first part and the second part of the package.

Abstract: An X-ray collimator (30) that comprises: a collimator body (31) comprising: a collimation conduit (32) provided with an inlet (320), configured to be connected to an X-ray source (20) for the inlet of a beam (B) of X-rays, and an outlet (321), configured to emit a collimated portion (B1) of the X-ray beam (B); and a derivation conduit (33) inclined with respect to the collimation conduit (32), wherein the derivation conduit (33) is provided with an inlet (330), configured to be connected to the X-ray source (20) for the inlet of a peripheral portion (B2) of the same X-ray beam (B) emitted by the source (20), and an outlet (331); a reference detector (40) fixed to the collimator body (31) and provided with an inlet window (41) facing the outlet (331) of the derivation conduit (33).

Abstract: An extreme ultraviolet light generation device configured to generate extreme ultraviolet light by irradiating a target containing tin with a pulse laser beam includes a chamber container, a hydrogen gas supply unit configured to supply hydrogen gas into the chamber container, a heat shield disposed between the chamber container and a predetermined region in which the target is irradiated with the pulse laser beam inside the chamber container, a first cooling medium flow path disposed in the chamber container, a second cooling medium flow path disposed in the heat shield, and a cooling device configured to supply a first cooling medium to the first cooling medium flow path and supply a second cooling medium to the second cooling medium flow path so that a temperature of the heat shield becomes lower than a temperature of the chamber container.

Abstract: A plane source blackbody is provided. The plane source blackbody comprises a panel and a carbon nanotube composite material. The panel comprising a first surface and a second surface, and the first surface is opposite to the second surface. The carbon nanotube composite material is located on the first surface. The carbon nanotube composite material comprises a black lacquer and a plurality of carbon nanotubes, and the plurality of carbon nanotubes is dispersed in the black lacquer.

Abstract: A gauge is provided for measuring one or more characteristics of a construction material such as a road surface. The gauge includes a detector, a base that carries the detector, and a source housing carried by the base and defining a shield material circumferentially extending inwards. A source rod is positioned within the housing and carries a source that is translatable between a shielded position within the housing and a measuring position external of the housing. The source rod has a source shield on the top thereof and a shield material spaced-downwardly from the source such that the source is completely enclosed when contained within the base.

Abstract: A method of inspecting a pipe includes locating a container around a pipe when the container is in an open position and moving the container from the open to a closed position. Then passing radiation through the container and at least a portion of the pipe substantially enclosed by the container. The distance between a source of the radiation and the at least a portion of the pipe being equal to or less than 300 mm. An apparatus comprising a container moveable between an open and a closed position. In the open position the container is locatable around a pipe and in the closed position the container substantially encloses at least a portion of the pipe. In the closed position the distance between a source of radiation enclosed in the container and the at least a portion of the pipe is equal to or less than 300 mm.

Abstract: The present disclosure relates to a radiographic shield incorporating a radiographic shutter mechanism, and a protective jacket for a radiographic device. The radiographic shutter mechanism includes machined tungsten components which in some embodiments, includes a jigsaw puzzle type interconnection, the radiographic shield includes an S-shaped passageway in combination with the radiographic shutter mechanism. The protective jacket allows for various mounting configurations, such as integrated SCAR mounting configurations, including a ratchet snap configuration.

Abstract: A particle beam irradiation apparatus radiates a particle beam plural times per one irradiation position. A storage unit stores a dose to be radiated each of the times (divisional target dose). A dose monitor measures the dose of the particle beam radiated to the irradiation position. At the first time of radiation, a controller outputs an interruption signal when the dose measured by the dose monitor reaches the divisional target dose. The dose monitor measures a dose (excessive dose) radiated after the interruption signal is outputted until the particle beam is actually interrupted. Then, it is defined: Corrected Dose value=Divisional Target Dose?Excessive Dose Value. Instead, it may be defined: Corrected Dose value=Divisional Target Dose?Excessive Dose Estimation Value. At the second time of radiation, the controller outputs an interruption signal when the dose measured by the dose monitor reaches the corrected dose value.

Abstract: An RF shield for enclosing a robotic tester unit while testing mobile devices. In some embodiments, the RF shield includes at least two conductive RF shield layers separated by an insulator material. In some embodiments, an inner surface of the RF shield is further lined with a RF absorbing material to absorb EM radiation generated within the RF Shield enclosure. In some embodiments, the internal components required for testing, e.g. the robot, are powered via a power conditioner that removes from the power source frequencies above a threshold, e.g. 100 Hz, to eliminate RF signals absorbed into the power lines via radio towers and/or intentionally induced into the power lines to control power equipment.

Abstract: When generating a magnetic resonance (MR) attenuation map (39), an MR image is segmented to identify a patient's body outline, soft tissue structures, and ambiguous structures comprising bone and/or air. To distinguish between bone and air in the ambiguous structures, a nuclear emission image (e.g., PET) of the same patient or region of interest is segmented. The segmented functional image data is correlated to the segmented MR image data to distinguish between bone and air in the ambiguous structures. Appropriate radiation attenuation values are assigned respectively to identify air voxels and bone voxels in the segmented MR image, and an MR attenuation map is generated from the enhanced segmented MR image, in which ambiguity between air and bone has been resolved. The MR attenuation map is used to generate an attenuation-corrected nuclear image, which is displayed to a user.

Abstract: An electromagnetic radiation delivery apparatus for tissue treatment, including a source of electromagnetic radiation, an emission window which is optically coupled to the source of electromagnetic radiation and is able to emit electromagnetic radiation, at least one recess provided in a skin contact area, and a pressure gauge for measuring a pressure inside the recess or a pressure correlated therewith. The electromagnetic radiation delivery apparatus for tissue treatment includes a pump for creating an overpressure inside the recess.

Abstract: The systems for determining and imaging wax deposition and simultaneous corrosion and wax deposit determination in pipelines relate to systems for determining wax deposition and corrosion by one or both of two techniques. In both techniques, a source of neutron radiation is directed at the pipeline. In one technique, a neutron detector surrounded by an absorption shield defining a collimation window counts neutrons reflected back to the detector by back diffusion or backscatter radiation. In the other technique, a gamma ray detector measures gamma rays emitted when the emitted neutrons are absorbed in the pipeline. A neutron moderator-reflector is placed around three sides of the pipeline to increase the likelihood of neutron capture.

Abstract: Devices and methods for the characterization of areas of radiation in contaminated rooms are provided. One such device is a collimator with a collimator shield for reducing noise when measuring radiation. A position determination system is provided that may be used for obtaining position and orientation information of the detector in the contaminated room. A radiation analysis method is included that is capable of determining the amount of radiation intensity present at known locations within the contaminated room. Also, a visual illustration system is provided that may project images onto the physical objects, which may be walls, of the contaminated room in order to identify the location of radioactive materials for decontamination.

Abstract: A radiation shield for use in treating spinal metastatic disease is formed of a body that is configured to surround the spinal cord and includes a section that can be axially extended for increasing the surface area of the shield.

Abstract: The present invention relates to a 68Ga generator, wherein the 68Ge parent nuclide thereof is attached specifically to a support through a triethoxyphenyl group and continuously disintegrates to 68Ga, the triethoxyphenyl group being covalently bound to a support material through a linker.

Abstract: A Gallium-68 (Ga-68) radioisotope generator includes a generating column and a citrate eluent. The generating column is at least partially filled with an ion-exchange resin with glucamine groups to absorb germanium-68 (Ge-68) and Ga-68 radioisotopes. The citrate eluent is added into the generating column to desorb the Ga-68 radioisotope and form an eluent containing the Ga-68 radioisotope in the form of Ga-68 citrate. A method for generating Ga-68 radioisotope is also disclosed.

Abstract: A target supply unit may include: a target storage unit for storing a target material thereinside; a target output unit having a through-hole formed therein, through which the target material stored inside the target storage unit is outputted; an electrode having a through-hole formed therein arranged to face the target output unit, the electrode being coated with an electrically conductive material at least on a part of a surface facing the target output unit; and a voltage generator for applying a voltage between the target material and the electrode.

Abstract: A movable device for measuring physical quantities of nuclear materials contained in a shielded cell, which device can be brought up against the shielded cell and can be retracted therefrom, the device configured to carry out the measurement in the position in which it is against the shielded cell. The device includes a carriage, a support member placed on the carriage, and a shielded container placed on the support member. The shielded container includes a transfer container configured to store the nuclear material to be measured, and an opening configured to be aligned with an opening in one wall of the shielded cell. The support member is made of graphite and includes a housing accommodating a neutron emission module, a casing covering the shielded container, the casing being made of graphite, and a neutron measurement mechanism fastened to the casing.

Abstract: A plurality of first plate members 10 is stacked with long side ends 10LT1 and 10LT2 thereof abutting to each other. Plate member joint bodies 100 are formed by attaching connecting members 30 to side surfaces 10S of the stacked first plate members 10, and connecting the first plate members 10. Further, the plate member joint bodies 100 are so disposed to face each other, and the connecting members 30 projecting from the side surfaces 10S of the first plate members 10 are inserted into recesses formed at both long side ends of second plate members 20. A recycled fuel assembly storage basket 1 is thus formed. Recycled fuel assemblies are stored in spaces surrounded by the first plate members 10 and the second plate members 20.

Abstract: A chip-scale infrared emitter package comprises an emitter chip and an enclosure. The emitter chip includes: a base having a central cavity; a membrane having a peripheral end, the peripheral end being isolated from a periphery of the central cavity by a loop-shaped gap; an electric resistor formed on the membrane; at least one slim supporting beam extending from the peripheral end of the membrane through the loop-shaped gap to the base; and a reflective material coated on the membrane. The enclosure has a can housing and a transparent window plate. The window plate cooperates with the can housing to define an enclosed vacuum chamber. The emitter chip is mounted in the enclosed vacuum chamber. The enclosed vacuum chamber has a pressure less than 0.01 torr.

Abstract: The present invention relates to a radiation measurement instrument calibration facility with the abilities of lowering scattered radiation and shielding background radiation and it is capable of providing a suitable environment for performing performance test, calibration and experiment upon a radiation measurement instrument. In an embodiment, the calibration facility comprises: a shielding device, a collimator, a multi-source irradiator, a radiation baffle, a carrier, an electric door unit and a control unit. With the design of the calibration facility of the present invention, the interference coming from the background radiation and scattered radiation in the laboratory during the radiation measurement instrument calibration can be effectively reduced to enhance the accuracy of measurement or calibration for the instrument, and also the instrument calibration and testing can be performed in radiation fields of low-, medium- and high-dose rate levels to meet the requirements of ISO 4037-1 (1996) Standard.

Abstract: An extreme ultraviolet light source apparatus in which only particles having a high transmittance for EUV light adhere to an EUV collector mirror even if fast ions emitted from plasma collide with a structural member in a vacuum chamber, and thereby, the reflectance thereof is not easily degraded. The apparatus includes: a vacuum chamber; a target supply unit for supplying a target to a predetermined position in the vacuum chamber; a driver laser for applying a laser beam to the target to generate the plasma; a collector mirror for collecting and outputting extreme ultraviolet light emitted from the plasma; a collector mirror holder for supporting the collector mirror; and a shielding member formed of a material having a high transmittance for the extreme ultraviolet light, for shielding the structural member such as the collector mirror holder from the ions generated from the plasma.

Abstract: A magnetically shielded, efficient plasma generation configuration for a pulsed discharge extreme ultraviolet (EUV) light source comprises two opposed convex electrodes mounted with axes parallel to a static magnetic field. A limiter aperture disposed between the electrodes, in conjunction with the field lines, defines a hollow plasma cylinder connecting the electrodes. A high pulsed voltage and current compresses the plasma cylinder and its interior magnetic field onto the electrode surfaces to create a magnetic insulating layer at the same time as propelling the working gas from each side toward the space between the electrode tips. The plasma then collapses radially in a three-dimensional compression to form a dense plasma on the axis of the device with radiation of extreme ultraviolet light.

Abstract: Disclosed herein are embodiments of a radiation shielding lid of a radiation shielding container (e.g., auxiliary radiation shield) designed to house a radioisotope generator assembly.

Abstract: A layered barrier for a compact particle facility is provided; the layered barrier includes a first layer formed from first shielding elements and a second layer formed from second shielding elements. The first and second shielding elements are modular and have different shielding characteristics from one another.

Abstract: A first image including a projection of a portion is generated based on data representing attenuation of higher-energy radiation having a peak energy of at least 1 MeV that passes through a portion of an inspection volume. A second image including a projection of the portion is generated based on data representing attenuation of lower-energy radiation passing through the portion of the inspection volume. A dual-pixel image is created from the first image and the second image. A region of interest is selected from the dual-pixel image. A first basis function that is derived from an attenuation characteristic associated with the region of interest is selected. The region of interest is represented in terms of an amplitude associated with the first basis function and an amplitude associated with the second basis function.

Abstract: The sterilizing toybox apparatus addresses illness risk, especially with children, by providing UV light sterilization within. UV lighting is offered both above and beyond toys within the apparatus. A time-release latch ensures exposure for a time determined to be optimal for UV exposure of contents. The apparatus provides UV lighting both in the bottom of the chest and in the lid. The clear shelf above the lower UV bulbs is in communication with the vibrator that jostles any toys so that full UV exposure is ensured. Reflective material distributed fully within the chest further guarantees full exposure of contents to sterilization. Additionally, the optional mesh basket is selectively suspended within the chest.

Abstract: Micro-channel-cooled UV curing systems and components thereof are provided. According to one embodiment, a lamp head module includes an optical macro-reflector, an array of LEDs and a micro-channel cooler assembly. The array is positioned within the reflector and has a high fill factor and a high aspect ratio. The array provides a high irradiance output beam pattern having a peak irradiance of greater than 25 W/cm2 at a work piece surface at least 1 mm away from an outer surface of a window of the reflector. The micro-channel cooler assembly maintains a substantially isothermal state among p-n junctions of the LEDs at less than or equal to 80° Celsius. The micro-channel cooler assembly also provides a common anode substrate for the array. A thermally efficient electrical connection is formed between the array and the common anode substrate by mounting the array to the micro-channel cooler assembly.

Abstract: In one embodiment, a system includes a first cold noise source, a first radiometer receiver, and a first detector. The first cold noise source generates a first thermal radiation signal having a first carrier frequency band. The first thermal radiation signal carries a first information signal. The first cold noise source also transmits the first thermal radiation signal through a first antenna. The first radiometer receiver receives the first thermal radiation signal through a second antenna, and the first detector extracts the first information signal from the first thermal radiation signal.

Abstract: The present invention is related to an irradiation cell for producing a radioisotope of interest through the irradiation of a target material by a particle beam, comprising a metallic insert forming a cavity designed to house the target material and to be closed by an irradiation window, wherein said metallic insert comprises at least two separate metallic parts of different materials, being composed of at least a first part comprising said cavity.

Abstract: A calibrated radioactive source comprises a container and a material labelled by at least one radionuclide. The labelled material is contained in the container and the container is made of a material that is transparent to the radiation emitted by the at least one radionuclide. The source is characterized in that the labelled material is a self-hardening polymer that is chemically inert relative to the material used for the container and in that the container is a flexible sheath. The calibrated source is placed into a hole of a brick of a tissue-equivalent phantom. An assembly is formed by such a calibrated source and a brick of tissue-equivalent phantom.

Abstract: A radiation source container comprising: a radiation source capsule (1); a radiation source holder (4) having an aperture (B) that emits unidirectionally radiation emitted from a radiation port A of the radiation source capsule, that provides screening such that no leakage of radiation takes place except from this aperture, and that fixes this radiation source capsule (1) in a manner that is difficult to attach or detach; a container (7) that accommodates the radiation source holder (4) and that has an irradiation window (C) that transmits radiation emitted from the aperture; an attenuation plate (3) provided between the radiation port of the radiation source capsule and the irradiation window, that attenuates beforehand the amount of radiation emitted; a shutter (6) provided between the attenuation plate (3) and the irradiation window (C) and that screens the radiation emitted from the irradiation window; and a capsule cover whereby, when the recommended use period in respect of the sealing performance of th

Abstract: Attenuating masks for selective attenuation of radiation, particularly from an x-ray source in brachytherapy, employ materials having atomic number in a specific range, so as to attenuate radiation dose intensity generally proportionally through a range of distance from the source. Some preferred attenuation materials are silver and molybdenum. A set of small masks can be provided for a particular design of catheter that holds a radiation source, each mask having a size and shape to define a different solid angle of masking, so that in a brachytherapy procedure, sensitive tissue such as bone or skin can be protected by proper selection of and positioning of the attenuating mask, to reduce the dose intensity to that tissue.

Abstract: There is provided a material activating device capable of being formed in any one of various shapes and having an improved material activating effect. A material activating device formed by superposing a plurality of polymer film 31 each having one surface coated with a metal film 32, and radioactive layer 33 of a radioactive means has a very small thickness and is very flexible. The metal films 32 are insulated from each other by the electrically insulating polymer films 31 and are spaced from each other by a distance corresponding to the thickness of the polymer films 31. Consequently, the material activating effect of the radioactive rays emitted by the radioactive layer 33 of the radioactive means is enhanced.

Abstract: A scanned beam imaging system including a radiation source configured to provide a beam of radiation, a movable element configured to direct the beam of radiation onto a scanned area, and a collector configured to receive radiation returned from the scanned area. The imaging system further includes a housing that houses the movable element therein and a reference mark coupled to or received in the housing. The reference mark is positioned such that at least part of the radiation from the radiation source is directable at the reference mark.

Abstract: The present invention relates to an adjusting positioner for a radiation device, comprising: a clamping device detachably connected to the radiation device to clamp said radiation device; a supporter to which said clamping device is connected and a slide path is defined therebetween, wherein the clamping device clamping said radiation device is movable along said slide path in a predetermined direction; and an adjusting device coupled with said clamping device so as to drive said clamping device to move along said slide path. Since the present invention employs above technical solution, it is easy to adjust the position of the radiation device for example, X-ray device, so that the precisely positioning for the radiation device is achieved and a satisfying positioning accuracy is able to obtain.

Abstract: An ultraviolet radiation curing system is disclosed for treating a substrate, such as fiber optic cable or silicone tubing. The system comprises a processing chamber allowing transport of a continuous piece of substrate to be treated. As the substrate moves through the processing chamber, ultraviolet radiation from a plasma lamp activated by a microwave generator treats the surface of the substrate. The system comprises two elliptical reflectors of different sizes so that larger diameter substrates may be efficiently treated with ultraviolet radiation. The system may also comprise an ultraviolet-transmissive conduit enclosing the substrate and split into a first portion and a second portion, where the second portion is movable from the first portion to open the conduit and allow insertion or alignment of the substrate within the conduit and processing chamber.

Abstract: The present invention provides a charged particle beam system which can perform evacuation on an electron gun chamber or an ion-gun chamber having a non-evaporable getter pump in a short time and can maintain the ultra-high vacuum for a long time, and a technology of evacuation therefor.

Abstract: A shielding assembly for use in a semiconductor manufacturing apparatus, such as an ion implantation apparatus, includes one or more removable shielding members configured to cover inner surfaces of a mass analyzing chamber. The shielding assembly reduces process by-products from accumulating on the inner surfaces. In one embodiment, a shielding assembly includes first and second shielding members, each having a unitary construction and configured to cover a magnetic area in the mass analyzing chamber. The shielding members desirably are made entirely of graphite or impregnated graphite to minimize contamination of the semiconductor device being processed caused by metal particles eroded from the inner surfaces of the mass analyzing chamber.

Abstract: The invention refers to a device (1) and method for sterilizing partly formed packages (6) in a packaging machine. The device (1) comprises an inner chamber (2) and an outer chamber (3), the inner chamber (2) being provided with a sterilization unit (5). Further, it comprises a carrier unit (10), comprising a separating member (11) and a package carrying member (12), which is being adapted to rotate between a first position in which the package carrying member (12) is located in the outer chamber (3), and in which the separating member (11) separates the inner chamber (2) from the outer chamber (3), and a second position in which the carrier unit (10) has rotated a package (6) into the inner chamber (2) and in which the separating member (11) separates the inner chamber (2) from the outer chamber (3).

Abstract: A nozzle protection device capable of protecting a target nozzle from heat of plasma without disturbing formation of a stable flow of a target material in an LPP type EUV light source apparatus. This nozzle protection device includes a cooling unit which is formed with an opening for passing the target material therethrough, and which is formed with a flow path for circulating a cooling medium inside, and an actuator which changes a position or a shape of the cooling unit between a first state of evacuating the cooling unit from a trajectory of the target material and a second state of blocking heat radiation from the plasma to the nozzle by the cooling unit while securing a path of the target material in the cooling unit.

Abstract: The present invention provides a charged particle beam apparatus that keeps the degree of vacuum in the vicinity of the electron source to ultra-high vacuum such as 10?8 to 10?9 Pa even in the state where electron beams are emitted using a non-evaporable getter pump and is not affected by dropout foreign particles. The present invention includes a vacuum vessel in which a charged particle source (electron source, ion source, etc.) is disposed and a non-evaporable getter pump disposed at a position that does not directly face electron beams and includes a structure that makes the non-evaporable getter pump upward with respect to a horizontal direction to drop out foreign particles into a bottom in a groove, so that the foreign particles dropped out from the non-evaporable getter pump do not face an electron optical system.

Abstract: A variable-ratio neutron-gamma ray source comprises a neutron generator, a shield, a collimator, and an external gamma target. The neutron generator generates neutrons and the shield reduces external radiation exposure. The collimator collimates the neutrons into a neutron beam that traverses the shield. The external gamma target generates a dual neutron-gamma ray beam from the neutron beam, wherein the dual neutron-gamma ray beam has a variable neutron-gamma ratio as a function of a thickness of the external gamma target.

Abstract: A dual neutron-gamma ray source comprises a compact neutron generator, a shield, a collimator, and an internal gamma target. The shield surrounds the compact neutron generator. The collimator traverses the shield from the compact neutron generator to a collimator port. The internal gamma target is positioned within the collimator to generate gamma rays from the neutrons.

Abstract: There is provided a material activating device capable of being formed in any one of various shapes and having an improved material activating effect. A material activating device formed by superposing a plurality of polymer film 31 each having one surface coated with a metal film 32, and radioactive layer 33 of a radioactive means has a very small thickness and is very flexible. The metal films 32 are insulated from each other by the electrically insulating polymer films 31 and are spaced from each other by a distance corresponding to the thickness of the polymer films 31. Consequently, the material activating effect of the radioactive rays emitted by the radioactive layer 33 of the radioactive means is enhanced.

Abstract: The invention relates to an apparatus for preparing a small amount of a radioactive substance combination, including a one-part body, a mixing device integrated in the body and adapted to receive a small amount of chemical substances, and at least one receptacle integrated in the body and connected to the mixing device and adapted to hold a small amount of a chemical substance.

Abstract: A variable-ratio neutron-gamma ray source comprises a neutron generator, a shield, a collimator, and an external gamma target. The neutron generator generates neutrons and the shield reduces external radiation exposure. The collimator collimates the neutrons into a neutron beam that traverses the shield. The external gamma target generates a dual neutron-gamma ray beam from the neutron beam, wherein the dual neutron-gamma ray beam has a variable neutron-gamma ratio as a function of a thickness of the external gamma target.

Abstract: A dual neutron-gamma ray source comprises a compact neutron generator, a shield, a collimator, and an internal gamma target. The shield surrounds the compact neutron generator. The collimator traverses the shield from the compact neutron generator to a collimator port. The internal gamma target is positioned within the collimator to generate gamma rays from the neutrons.