• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
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  • 法律状态
  • 优先权
    • 专利摘要:
    Device (7) for the detection of radiation, preferably X-radiation, comprising at least one detector element (11) comprising an absorber element (1) for the radiation and a nanowire (2) made of a superconducting material in thermally conductive connection with the absorber element (1) wherein cooling means (34) are provided to cool the absorber element (1) and the nanowire (2) to a temperature in the region of the transition temperature of the nanowire (2) in an operating state of the device (7), and wherein an evaluation and control unit (6) for determining whether or not the nanowire (2) is in a superconducting state. According to the invention, provision is made for at least one heating means (8) which can be activated by means of the evaluation and control unit (6) to be able to supply a thermal energy pulse to the absorber element (1), the evaluation and control unit (6) being designed to in order to continuously supply energy pulses to the absorber element (1) in the operating state of the device (7) as long as the nanowire (2) is in the superconducting state.
    公开号:AT517438A1
    申请号:T50587/2015
    申请日:2015-07-07
    公开日:2017-01-15
    发明作者:
    申请人:Alfred Dipl Ing Fuchs；
    IPC主号:
    专利说明:

    DEVICE AND METHOD FOR DETECTING RADIATION
    FIELD OF THE INVENTION
    The present invention relates to a device for detecting radiation, preferably X-ray radiation, the device comprising at least one detector element which has an absorber element for the radiation and a nanowire made of a superconducting material thermally conductively connected to the absorber element, wherein cooling means are provided in an operating state of the device, to cool the absorber element and the nanowire of the at least one detector element to a temperature in the region of the transition temperature of the nanowire, and wherein an evaluation and control unit for determining whether or not the nanowire of the at least one detector element is in a superconducting state , is provided.
    The present invention further relates to a method for detecting radiation, preferably X-radiation, wherein an absorber element and a nanowire arranged in thermally conductive connection with the absorber element are cooled from a superconducting material to a temperature in the region of the transition temperature of the nanowire, wherein the absorber element Radiation is absorbed and it is continuously determined whether the nanowire is in a superconducting state or not.
    STATE OF THE ART
    X-rays are used for analysis purposes in various fields of medicine and medicine. It is generally desirable to increase the detection sensitivity of X-ray detectors in order to improve an achievable spatial resolution and / or to reduce the dose loading for an examination subject. The latter plays an important role, especially in the medical field, since high dose levels can lead to health impairments of patients. In particular, computed tomography and mammography should be mentioned. In the latter case, a high total dose fails negatively, in the latter case the routine repetition leads to a high total dose over time.
    In the past, X-ray detectors were mostly used, which exploited xenon gas ionization induced by X-ray radiation to measure X-ray radiation. In the meantime scintillation detectors are mainly used whose detection sensitivity is essentially determined by the choice of the scintillator material.
    In principle, the optimization of detectors, of course, not only for X-ray radiation, but for a variety of types of radiation in various fields of technology and in medicine is involved.
    From astronomy are e.g. especially for the measurement of electromagnetic radiation in the optical and infrared range, detectors are known which operate at very low temperatures and are designed as calorimeters or bolometers. The amount of energy or power that deposits the radiation in an absorber is measured. Due to the low temperatures superconducting materials can be used as absorbers, which are initially just below the
    Held transition temperature and be warmed up by the absorbed radiation on the transition temperature, wherein the sharp transition between superconductivity and normal line is used for detection. Achievable temporal resolutions are typically in the ms range or just below, which is too slow, especially for medical computed tomography applications.
    OBJECT OF THE INVENTION
    It is therefore the object of the present invention to provide an apparatus and a method which make possible a rapid and highly sensitive detection of radiation, in particular X-ray radiation, in order to improve an achievable spatial resolution during the examination of a test object using radiation / or to reduce a dose load for the examination subject.
    PRESENTATION OF THE INVENTION
    The core of the invention is the linking of the principle of a delta-sigma analog-to-digital converter (sigma-delta ADC) or delta-sigma converter with elements of known from astronomy bolometers. In this case, superconducting elements are used and the striking transition between superconductivity and normal conduction is exploited for detection. Due to the use of superconducting elements for detection, extremely high quantum efficiency can be achieved. Specifically, in the case of a device for detecting radiation, preferably X-ray radiation, the device comprises at least one detector element which has an absorber element for the radiation and a thermally conductive one with the absorber element
    Having connecting nanowire of a superconducting material, wherein cooling means are provided to cool in an operating state of the device, the absorber element and the nanowire of the at least one detector element to a temperature in the range of the transition temperature of the nanowire, and wherein an evaluation and control unit for determining Whether or not the nanowire of the at least one detector element is in a superconducting state is provided according to the invention that at least one heating means controllable by the evaluation and control unit is provided in order to be able to supply a thermal energy pulse to the absorber element of the at least one detector element. wherein the evaluation and control unit is designed to continuously supply energy pulses to the absorber element of the at least one detector element in the operating state of the device, as long as the nanowire of the at least one detector element is in the superconducting one State is.
    The nanowire can take on two states: superconducting or "high resistance," with the transition between these two states being very fast, with response times in the range of 1 ns or even less than 1 ns, by continuously supplying energy in small increments to the absorber element through the heating medium As a result of the thermally conductive connection to the nanowire, its temperature is thus continuously increased in small increments until the state of the nanowire changes The energy input of a possible measuring current through the nanowire is negligible or can be corrected by calibration
    Nanowire superconducting again when it falls below the critical temperature.
    The power required to bring the absorber element to that temperature level at which the nanowire is on average just at the transition temperature can be calculated directly from the sequence of pulses.
    If, in addition, radiation strikes the absorber element, correspondingly fewer energy pulses must be supplied to the absorber element by the heating element since the absorbed radiation also leads to an increase in the temperature of the absorber element in small increments-typically in the range of mK. That the radiation incident on the absorber element corresponds to the complementary power required for the state transition of the nanowire from superconducting to high-ohmic, thus providing a measure of the intensity of the absorbed radiation.
    The basic principle is known in electronics as a simple delta-sigma ADC. In the present case, a thermal delta-sigma converter is realized in which the working variable is not voltage or current but the temperature. As a result, a digitization is achieved in an intrinsic manner.
    The thermal time constant of a detector element is due to the thermal Trågheit of the system from the absorber element with a certain low Wämmekapazitåt and thermally conductively connected nanowire in the ps range, which determines the possible time resolution of a measured value. Due to the extremely fast reaction time of the nanowire, a very efficient readout can be carried out, which is especially true for a plurality of detector elements which represent pixels of a detector and, e.g. in line or matrix form is of great advantage. It is then not necessary for each detector element or pixel own
    To build a readout circuit that would be structurally complex, expensive and space-consuming and would lead to a poor production yield. Instead, the available space can be used for sensitive areas, and the read-out can be carried out serially in a temporal multiplexing process because of the intrinsically high reaction time of the nanowire. Practically achievable readout rates are typically in the range of 100 MHz to 500 MHz, preferably in the range of about 300 MHz. That the number of detector elements connected in series can easily be of the order of 1000, if time resolutions of a few kHz or 10 kHz, as they are customary in the medical field, are required.
    Accordingly, it is provided in a preferred embodiment of the device according to the invention that a plurality of detector elements are provided.
    In principle, the detector elements can be arbitrarily arranged, whereby, as already stated, a large number of detector elements can be read out in series. In order to facilitate the serial readout constructively or by the arrangement of the individual detector elements relative to one another, it is provided in a particularly preferred embodiment of the device according to the invention that the detector elements are arranged along at least one line, preferably along several lines, particularly preferably along several parallel lines , It makes sense to read each of the detector elements of a line serieil. The lines do not have to run straight, but can in principle also be curved and, for example, curved. be executed as a circular arc. Furthermore, from the lines in a simple form, it is also possible to realize a matrix-shaped arrangement or, in general, a raster-shaped arrangement of the detector elements.
    Analogous to the above, it is in a method for detecting radiation, preferably X-radiation, wherein an absorber element and a standing with the absorber element in thermally conductive connection nanowire made of a superconducting material to a temperature in the range of the transition temperature of the nanowire are cooled, Mitteis of Absorber element, the radiation is absorbed and it is continuously determined whether the nanowire is in a superconducting state or not, inventively provided that the middle of a heating means the energy absorber element continuously energized be supplied as long as the nanowire is in the superconducting state, and thereby the absorber element supplied power is determined.
    The device according to the invention or the method according to the invention is suitable for radiations of the most varied types. Radiation in the broadest sense means any type of radiation that results in an energy input in the absorber, which energy input in turn leads to a certain warming of the absorber. Examples of possible different types of radiation are: ionizing radiation, in particular X-ray radiation, alpha, beta or gamma radiation; generally electromagnetic radiation, in particular in the optically visible range or in the infrared range or UV range; Sound; Particles adsorbed on the absorber; Particles that trigger a chemical reaction on or in the absorber.
    It is understood that while the absorber must be adapted to the particular type of radiation. That The absorber must clearly be designed so that there is a zero zero interaction cross section for the radiation to be detected.
    In order to ensure a particularly good absorption of X-ray radiation, it is provided in a preferred embodiment of the device according to the invention that the absorber element of the at least one detector element is made of bismuth. The surface of the absorber element can be rendered inert for practical reasons, in particular for protection against chemical environmental influences, e.g. by fluorination.
    The absorber element can be geometrically dimensioned accordingly, on the one hand to ensure a sufficiently high cross-section and on the other hand to allow a high spatial resolution. For example, the absorber element can be designed as a platelet with lateral dimensions with side lengths of between 1 μm and 200 μm, preferably between 10 μm and 100 μm. In the case of X-ray radiation to be detected, the cross-section can be adapted to the energy of the X-ray radiation by suitable choice of the thickness - the harder the radiation, the thicker the platelet. At energies of Rontgen radiation, as e.g. in medical applications, the thickness of the absorber element may be e.g. be between 50 pm and 200 pm, preferably between 75 pm and 150 pm. That in this case, the thickness is typically of the same order of magnitude as the side length of the absorber element.
    Thus, extremely high achievable spatial resolutions result, which render the device according to the invention or the method according to the invention particularly suitable for applications in medicine, such as e.g. prämdestinieren in mammography.
    Generally, nanowire is understood to mean a wire whose dimensions can usually be greater than a few nanometers and typically in the range of about 100 nm.
    As a coolant for generating the low temperature, for example, a Kåltebad be used with a Kiihlflussigkeit, with which Kåltebad the absorber element and the nanowire are thermally conductively connected. For such a thermally conductive connection, in particular, a carrier is made of a material which has a particularly high thermal conductivity at low temperatures, such as e.g. Sapphire, in question, with which the absorber element and the nanowire are thermally conductively connected. Depending on the transition temperature of the nanowire, different cooling fluxes may be used, e.g. liquid helium or liquid nitrogen. That it usually does not need to be cooled to mK, but absorber and nanowire are typically cooled to temperatures in the range of a few K, preferably in the range of 4K to 77K, allowing the use of low cost cryostats. The transition temperature is fundamentally a material property of the nanowire, wherein the material may be a superconductor or possibly a high-temperature superconductor.
    Accordingly, it is provided in a preferred embodiment of the device according to the invention that the nanowire of the at least one detector element is made of niobium nitride or tantalum nitride. The actual transition temperatures may depend on the specific geometric dimensions and are typically in the range between 4 K and 16.5 K. Here, the transition temperature is also dependent on the current density in the nanowire and possibly also on an existing magnetic field, the latter being always below is assumed to be zero.
    It should be noted that the temperature of the nanowire and the temperature of the absorber element need not necessarily be exactly the same. In particular, the absorber element can be slightly warmer than the nanowire, but the reverse case is also conceivable.
    The absorber element has a very low heat capacity to ensure that an energy input by absorbed radiation causes a significant increase in the temperature of the absorber element. On the one hand, the material of the absorber element can be selected accordingly, on the other hand, the low temperature ensures a low heat capacity.
    In order to achieve a particularly good thermal connection between absorber element and nanowire, it is provided in a preferred embodiment of the device according to the invention that the absorber element of the at least one detector element is deposited on the nanowire of the at least one detector element.
    The determination of whether or not the nanowire is in the superconductive state can be made as a resistance measurement. In particular, for this purpose, a voltage drop can be determined on an ohmic resistor connected in series or parallel to the nanowire.
    As heating means with which thermal pulses can be generated, e.g. a source of radiation for electromagnetic pulses in the optical or infrared range. That the absorber element is supplied with these electromagnetic pulses to cause an incremental increase in the temperature of the absorber element. In this case, the radiation source can be arranged at a certain distance from the absorber element, which can be structurally advantageous.
    In a preferred embodiment of the device according to the invention, it is provided that as the at least one heating means an ohmic resistance is provided, which is thermally conductively connected to the absorber of the at least one detector element. This represents a manufacturing technology and structurally particularly simple variant. In order to generate the energy pulses, current pulses are applied to the ohmic resistor.
    For a particularly stable measuring arrangement, it is advantageous to apply or operate the nanowire during the measurement with current near the critical current density. Preferably, this is a precise constant current, but in principle a pulsed current would also be conceivable. Accordingly, in the manner described above, with the aid of the current energy pulses supplied to the absorber element, the power required to bring the absorber element up to the temperature level at which the nanowire is operating on average at the critical current density is determined becomes. Therefore, in a preferred embodiment of the device according to the invention, it is provided that a current source is provided in the operating state of the device, the nanowire of the at least one detector element in the range of 70% to 99%, preferably in the range of 80% to 95% of its critical current density to operate.
    In order to be able to use the device in various environments, in particular in air or in an atmosphere and preferably at room temperature, it is provided in a preferred embodiment of the device according to the invention that the at least one detector element is arranged in a thermally insulated vessel which is a window for the radiation to be detected. For X-ray radiation, e.g. Windows made of beryllium or plastic in question. Depending on the material of the vessel, the window can also be designed as a one-piece with the vessel. This, of course, depends on the type of radiation. In particular, it is conceivable that a special window can be dispensed with if e.g. Neutrons or very high-energy gamma quanta are to be detected.
    Due to the high detection sensitivity and the advantageous dimensioning possibilities, the device according to the invention and the method according to the invention are particularly suitable for measurements where radiation is to be detected, which is both weakened and scattered by an examination subject. This opens, e.g. in computed tomography methods, especially in the medical field, new possibilities, since so far only the weak radiation is detected and used for image reconstruction. Therefore, an arrangement is provided according to the invention for detecting radiation and weak radiation scattered in an examination object, the arrangement comprising a radiation source for generating a beam of specialists with partial beams having different beam angles for illuminating the examination object under different directions of incidence lying in a mid-plane of the fighter, comprising the arrangement further first device according to the invention and a second device according to the invention, wherein at least a part of the detector elements of the first device is arranged behind the examination subject as seen in the directions of incidence and wherein at least part of the detector elements of the second device are laterally offset parallel to an axis connecting the radiation source and the examination subject is arranged to the detector elements of the first device.
    The expert angles are measured in the mid-fielder plane, which also includes the directions of incidence. That each Fåcherwinkel corresponds to one direction of incidence. Of course, the Fåcher beam also has a certain angular extent in a normal plane normal to the center of the mid-stroke. Accordingly, in the
    Normal level an opening angle 2β of Facherstrahls are measured.
    Preferably, all detector elements of the first device are arranged in the direction of incidence behind the examination subject. Correspondingly, substantially all partial beams which, though weakened but undirected or "directly" pass through the examination object, can be detected by the first device.
    Conventional devices which are used to detect weak radiation and which are used in particular in computed tomography applications have arranged collimator septa between the detector elements. These are dimensioned so as to ensure that only partial beams passing directly through the examination subject are detected and no scattered partial beams. This in turn is usually accompanied by a considerable space requirement of the collimator septa and thus a considerable loss of sensitive detector surface.
    As will be explained in more detail below, collimator seams between the detector elements of the first device can be dispensed with in the present case.
    The detector elements of the first device thus detect both directly subdued by the subject to be examined, partial beams scattered as well as in the examination object scattered partial beams. Due to the absence of collimator seams between the detector elements of the first device, the detector elements of the first device can be arranged close to one another, so that a very large sensitive detector surface can be achieved.
    The detector elements of the second device serve in principle the detection of only one "sort" of radiation-scattered radiation or unscattered radiation.
    In the first exemplary embodiments, radiation scattered with the detector elements of the second device is detected exclusively. Therefore, it would also be conceivable in principle that, seen in the directions of incidence, a part of the detector elements of the second device is arranged in front of the examination object in order to detect jerk-scattered components. In order to ensure that no partial beams which have passed directly through the examination subject but only scattered partial beams are detected by the detector elements of the second apparatus, the, preferably all detector elements of the second apparatus are laterally offset relative to the detector elements of the first apparatus. "Sideways" can mean looking up, down, left or right.
    This opens up the possibility, based on the measured pure stray radiation, of subtracting a corresponding proportion of the measured sum of weakened and scattered radiation for each detector element of the first device and thus - without using collimator septa between the detector elements of the first device - on the exclusively weakened partial beams to close. For this purpose, it can be assumed, in particular, that the scattering of a partial beam through the examination object is at least approximately rotationally symmetrical about this partial beam. Accordingly, the detector elements of the second device are arranged offset to the detector elements of the first device, that in a rotationally symmetrical spatial distribution of the scattered radiation of the respective sub-beam, the same proportion of the respective sub-beam was scattered into the respective offset detector element of the second device as in one to each
    Detector element of the first device adjacent to the detector element of the first device, in which adjacent detector element would be measured for each partial beam adjacent weakened beam part. Basically any neighbors can be considered. In particular, not only the nearest neighbors can be considered as neighboring detector elements, but also superordinate neighbors, over-neighbor neighbors, etc. - in general neighbors of arbitrary order - can be taken into account.
    Accordingly, a method is provided according to the invention for detecting radiation and weak radiation scattered in an examination object, the examination object being illuminated with a fan beam with different partial beams having different angles, whereby a sum of partial beams and scattered radiation weakened in the examination subject is measured by means of a method according to the invention. wherein the measurement takes place in at least one dimension in a spatially resolved manner such that the individual partial beams are spatially resolved.
    Furthermore, in a particularly preferred embodiment of the method according to the invention for determining radiation and weak radiation scattered in an examination subject, it is provided that exclusively scattered radiation is measured by means of a further method according to the invention, wherein the measurement takes place in at least one dimension in at least one of these locations, in which, in the case of an assumed rotationally symmetric spatial distribution of the scattered radiation of each partial beam, the same proportion of the respective partial beam would be scattered as in a location at which a weakened partial beam adjacent to the respective partial beam is measured. That There is a spatially resolved measurement of individual partial beams.
    Likewise, in a preferred embodiment of the method according to the invention for determining radiation and weak radiation scattered in an examination subject, it is provided that the exclusively weakened radiation is computationally determined for the locations where the weakened partial beams are measured, in each case by the measured sum parts of the measured exclusively scattered radiation are subtracted from weak radiation and scattered radiation. Here, the concrete geometry of the detector elements of the first device and the second device is to be taken into account, in particular differences in the geometry of the detector elements. Arithmetic and weighting factors result in the simplest case alone from the geometry of the detector elements used. Furthermore, arithmetic and weighting factors may be deduced and adapted from a spatial modeling of the ray paths.
    In a preferred embodiment of the device according to the invention, it is provided that the detector elements of the first device are arranged along a line, which is preferably in the specialist center plane, that the detector elements of the second device are arranged along several lines and that viewed from the radiation source the lines of the detector elements of the second device alternately to each other and preferably to the line of the detector elements of the first device have a distance angle measured in a normal plane which is normal to the specialist center plane. This represents a structurally and production-technically particularly simple embodiment, wherein preferably all lines of the second device are arranged on the same side relative to the line of the first device. Overall lines can have the same distance angle to each other, but there are also different distance angles conceivable.
    In a preferred embodiment of the device according to the invention, it is provided that the course of the plurality of lines of the detector elements of the second device essentially follows the course of the line of the detector elements of the first device. The line of the first device may be curved and need not lie in a single plane. The course of the lines of the second device is then likewise correspondingly curved and does not have to lie in a single plane. In the simplest case, all lines are parallel straight lines, which are preferably in the same plane.
    In order to provide more sensitive detector areas and thus to increase the detection sensitivity, it is provided in a preferred embodiment of the device according to the invention that the detector elements of the first device are additionally arranged along a further line, that the detector elements of the second device additionally along further Lines are arranged and that seen from the radiation source from the other lines of the detector elements of the second device alternately to each other and preferably to the other line of the detector elements of the first device have a further distance angle, which is measured in the normal plane. All further lines can have the same additional distance angle to each other, but also different further distance angles are conceivable.
    In order to realize a structurally particularly simple arrangement, it is provided in a preferred embodiment of the arrangement according to the invention that the detector elements of the first device are arranged between the detector elements of the second device.
    In this way, an arrangement which is essentially symmetrical about the center of the axis of the forehead can preferably be realized, which has a high detection sensitivity.
    In a preferred embodiment of the arrangement according to the invention, it is provided that the course of the further line of the detector elements of the first device substantially follows the course of the line of the detector elements of the first device and that the course of the further lines of the detector elements of the second device follow the course of the further Line of the detector elements of the first device essentially follows. As already mentioned, the line of the first device may be curved and need not lie in a single plane. The course of all other lines is then likewise curved and does not have to lie in a single plane. In the simplest case, all lines are parallel straight lines, which preferably lie in the same plane.
    In a preferred embodiment of the arrangement according to the invention, it is provided that, as seen from the radiation source, the detector elements of the line and the further line of the first device have an offset angle to one another, which is measured in the mid-focus plane.
    As a result, the resolution of Facher angle is increased, preferably doubled. The detector elements of the first device need not be arranged in one plane or the line and the further line of the first device need not be arranged in one plane.
    Analogously, it is provided in a particularly preferred embodiment of the arrangement according to the invention that, viewed from the radiation source, the detector elements of the lines and the further lines of the second device have the offset angles to one another. The detector elements of the second device need not be arranged in one plane or the lines and the further lines of the first device need not be arranged in one plane.
    As I said, can on collimator septa between
    Detector elements of the first device are dispensed with, since the scattered radiation detected by these detector elements can be computationally eliminated based on the measurements with the second device. In order to ensure in the described embodiments with linearly arranged detector elements that the respective detector element of the second device detects only that scattered portion of a partial beam, which - assuming rotationally symmetric scattering - is also scattered into a respective detector element of the first device adjacent detector element of the first device in which the direct weakened portion of the sub-beam is detected by the respective detector element of the first device, collimator seams are provided between the detector elements of the second device. Therefore, in a preferred embodiment of the device according to the invention, it is provided that collimator septa are provided only between detector elements of the second device, wherein the collimator septa are preferably arranged between detector elements of the second device, which are arranged consecutively along one of the lines and / or the further lines ,
    Another possibility for achieving a high detection sensitivity is the flat or two-dimensional arrangement of the detector elements of the first and second device. By a rasterformige arrangement of the detector elements of the first device can be created gaps between these detector elements, in which the detector elements of the second device can be arranged. This results in a large total sensitive area for both the first device and the second device.
    To ensure that only one "sort" of radiation is detected with the second device, the detector elements of the second device are not only offset laterally but also behind the detector elements of the first device, ie, the detector elements of the second device have a greater distance to the radiation source The detector elements of the second device are arranged so far behind the detector elements of the first device that the former can practically only be reached by unscattered partial beams the sensitive surfaces of the absorber elements of the detector elements of the second device and the distance between these detector elements and those of the first device are adjusted accordingly.
    In a sense, the detector elements of the first device, which are reached by both scattered and unscattered sub-beams, thus act as collimator septa for the detector elements of the second device. To allow a structurally simple and cost-effective implementation, both the detector elements of the first device and the detector elements of the second device are arranged in parallel planes. Accordingly, it is provided in a preferred embodiment of the arrangement according to the invention that the detector elements of the first device are arranged in a first plane on a two-dimensional grid, that the detector elements of the second device are arranged in a second plane parallel to the first plane, that of the radiation source is arranged behind the first plane, and that seen in a normal direction on the two normal normal directions, the detector elements of the second device are arranged in gaps between the detector elements of the first device.
    In order to be able to determine for the detector elements of the first device how large the fraction of the unscattered radiation is in the total detected radiation, it is provided in a preferred embodiment of the device according to the invention that a third device according to the invention is provided whose detector elements are in a third plane are arranged, which is arranged parallel to the first plane and second plane and between the first plane and second plane, wherein the detector elements of the third device in the normal direction are hidden from the detector elements of the first device. Preferably, for each detector element of the first device, there is a corresponding detector element of the third device, which is arranged directly behind the respective detector element of the first device and is covered or shielded by it. The shielding of the detector elements of the third device by the detector elements of the first device causes the detector elements of the third device can not be achieved by unscattered partial beams, but only by scattered partial beams. The proportion of the direct or unscattered, weakened partial beams in the detector elements of the first device thus results by subtracting the scattered partial beams measured by the corresponding detector elements of the third device. Possibly. Calibration factors can be used here.
    In the case of precisely defined surface ratios between the detector elements or absorber elements of the first and second device, the third device can also be dispensed with. The size of the unscattered radiation Dldj in a detector element j of the first device can then be calculated as follows:
    with Dljd) the magnitude of the radiation measured in the detector element j or i of the first device (which is a sum of scattered and unscattered), D2j (i) the magnitude of the radiation measured in the detector element j or i of the second device (only direct or indirect) the unshielded radiation), the area ratio between the absorber elements of the first device and the second device minus 1, N is the number of considered detector elements resulting from the number of considered neighbors plus 1 (the detector element Dlj is taken into account in the sum).
    At a low radiation dose or at low intensity of the measured radiation, the detector elements of the first and second device have a quantum noise component, which is reduced by the summation. It is a valid assumption that the scattered radiation component has a lower spatial frequency than the unscattered component, since it consists of components of many propagation directions or of many scattered component beams and may therefore be averaged over a larger area. In particular, the quantization noise of the scattered radiation detection by the spatial averaging does not increase the noise of the measurement or calculation result. As a result, it is sufficient to arrange detector elements only in two levels, which is particularly friendly in terms of production technology.
    Finally, it should be noted that the detector elements can be produced very inexpensively, since in the simplest case they consist essentially only of a cheap chemical element and no too complex structures are required for the readout. The latter can e.g. by simple
    Vaporizing or microlithic structuring are generated.
    The specific arrangement of the detector elements of several devices, which makes it possible to dispense with collimator septa, is of course also possible with other detector elements, e.g. work with scintillators, possible. However, the use of devices according to the invention results in particularly favorable conditions, since the dimensions of the absorber elements in all three dimensions can be of the same order of magnitude of typically 10 μm to 100 μm.
    It should also be noted that the described arrangements for detecting radiation and weak radiation scattered in an object under investigation may also work with conventional radiation detection devices, although not as efficiently. For this purpose, in the arrangement described above, the devices according to the invention can in principle be replaced by all devices which have detector elements which are suitable for the detection of radiation and which allow arrangements of the detector elements along lines or raster-shaped structures.
    BRIEF DESCRIPTION OF THE FIGURES
    The invention will now be explained in more detail with reference to exemplary embodiments. The drawings are exemplary and are intended to illustrate the inventive idea, but in no way restrict it or even conclusively reproduce it.
    Showing:
    1 shows a schematic structure of a device according to the invention in side view
    Fig. 2 is a circuit diagram of the essential elements for the function of the device according to the invention
    Fig. 3 is a diagrammatic representation of the operation of the device according to the invention
    4 shows a device according to the invention for determining radiation scattered in an examination object and weak radiation in a schematic first side view
    5 shows the arrangement of FIG. 4 in a schematic second side view
    6 shows a schematic detail view of the devices according to the invention of the arrangement of FIGS. 4 and 5
    7 shows a further embodiment of the arrangement according to the invention in a view analogous to FIG. 4
    8 shows a schematic detail view of the devices according to the invention of the arrangement of FIG. 7
    9 shows a schematic detail view of devices according to the invention of a further embodiment of the arrangement according to the invention, wherein detector elements of the devices are arranged two-dimensionally in planes
    WAYS TO PERFORM THE ERF INDUNG
    1 shows the schematic structure of a device 7 according to the invention for the detection of radiation, the detection of X-ray radiation being assumed in the exemplary embodiments shown. The device 7 comprises a detector element 11 with an absorber element 1, which is typically made of bismuth, and with a superconducting nanowire 2, which is typically made of niobium nitride and is thermally conductively connected to the absorber element 1. Typically, the absorber element 1 is plättettformig executed, with a side length of the absorber element 1 for all three spatial dimensions in the range of 100 pm. Furthermore, an ohmic resistor 8 is provided, which is also thermally conductively connected to the absorber element 1.
    The absorber element 1 and the nanowire 2 are connected via a carrier 33, typically made of sapphire, to a cold bath 34, which kuhit the absorber element 1 and the nanowire 2 in an operating state of the device 7 to a temperature in the range of the critical temperature Tc of the nanowire 2. At these temperatures, the Tråger 33 has an excellent heat conduction. The cold bath 34 operates, for example, with liquid helium or liquid nitrogen.
    For thermal isolation to onien the detector element 11 and the cold bath 34 are arranged in a thermally insulating vessel 4 or a cryostat. So that X-ray radiation can strike the absorber element 1 unhindered under an incident direction 19, the vessel 4 has a window 5 which is substantially transparent to the X-ray radiation and which is made of beryllium in the exemplary embodiment shown.
    Furthermore, the device 7 has an evaluation and control unit 6, mitteis which is continuously determined in the operating state of the device 7, whether the nanowire 2 is superconducting or not.
    Dariiberhinaus can be applied to the evaluation and control unit 6 of the resistor 8 with current pulses. Since the pulse-fed energy is converted into heat in ohmic resistance, the current pulses represent a pulsed heating current iH. Due to the thermally conductive connection between the ohmic resistor 8 and the absorber element 1, energy can be supplied to the absorber element 1 in a pulsed manner and its temperature can be correspondingly increased Increments are increased - even if no radiation to be detected is present. The evaluation and control unit 6 is designed so that in the operating state of the device 7 to the absorber element 1 continuously supplied energy pulses, as long as the nanowire 2 is in the superconducting state. As soon as the nanowire 2 has a high resistance, no further energy pulses are supplied, whereupon the absorber element 1 cools again due to the cold bath 34.
    The power necessary to bring the absorber element 1 to that temperature level at which the nanowire is on average just at the transition temperature Tc can be calculated directly from the sequence of pulses.
    If, in addition, X-ray radiation strikes the absorber element 1, correspondingly fewer energy pulses must be supplied to the absorber element 1, since the absorbed X-ray radiation also causes the temperature of the absorber element 1 to increase in small increments, typically in the range of .mu.m mK - leads. That the radiation impinging on the absorber element 1 corresponds to the complementary power required for the change of state of the nanowire 2 from superconducting to high-impedance, which gives a measure of the intensity of the absorbed X-ray radiation.
    The basic principle is known in electronics as a simple delta-sigma ADC. In the present case, a thermal delta-sigma converter is realized in which the working variable is not voltage or current but the temperature T. As a result, a digitization is achieved in an intrinsic manner.
    The described mode of operation is illustrated in FIG. 3, which diagrammatically shows the time course of an intensity Ix of the X-ray radiation impinging on the absorber element 1, a temperature T of the nanowire 2, an electrical resistance Rn of the nanowire 2 and the heating current iH. In particular, in this case, the intrinsic digitization by the change of RN and by iH already apparent, with increasing intensity Ix of the nanowire 2 is always more often or long high impedance and the pulses of the heating current iH accordingly increasingly rare.
    In Fig. 2 is a circuit diagram of the essential for the operation of the device 7 elements shown. With a voltage source 3, a voltage is applied to the nanowire 2 and an ohmic resistor 25 connected in series to operate the nanowire 2 near its critical current density, preferably in the range of 80% to 95% of the critical current density. Accordingly, in the manner described above, with the aid of the current energy pulses supplied to the absorber element 1, the power required to bring the absorber element 1 up to the temperature level at which the nanowire 2 is in the middle straight is determined critical current density is operated.
    By means of a comparator 9 it is determined whether the nanowire 2 is superconducting or high impedance. Accordingly, with a subsequent to the comparator 9 flip-flop 10 of the ohmic resistance 8 is applied to a current pulse or not. The comparator 9, the flip-flop 10 and the voltage source 3 are in the illustrated embodiment of the evaluation and control unit 6 includes.
    The thermal time constant of a detector element 11 is due to the thermal Trågheit of the system from the absorber element 1 with a certain, low Wämmapapit and the thermally conductively connected nanowire 2 in ys-
    Range, which determines the possible time resolution of a measured value. Due to the very fast reaction times of the nanowire 2 in the sub-nanosecond range, many detector elements 11 can be operated in series and read out in a temporal multiplex method for many applications. Achievable readout rates are for example in the range of about 300 MHz. That the number of detector elements 11 connected in series can easily be of the order of 1000, if time resolutions of a few kHz or 10 kHz, as they are customary in the medical field, are required. The serially operated detector elements 11 may in particular be arranged linearly.
    FIGS. 4, 5 and 6 show an application example with detector elements 11 arranged in this way, the device 7, together with a further device 7 'according to the invention, being part of an arrangement for determining X-ray radiation 16 scattered in an examination subject 12 unscattered weak Rontgen radiation 17 is. The device 7 is therefore also referred to below as the first device 7 and the further device 7 'as the second device 7'. Such arrangements may e.g. used for computed tomography procedures. The arrangement comprises in the illustrated embodiment, a Rontgen radiation source 13, which generates a Rontgen-Facherstrahl 14.
    As can be seen in FIG. 5, the X-ray beam 14 is composed of X-ray partial beams 15 which have different beam angles 18 in the X-ray beam 14. The Facherwinkel 18 are measured in a specialist center level 20, which lies in the representation of FIG. 5 in the drawing plane.
    In a normal plane 24, which is perpendicular to the specialized center plane 20, the X-ray beam 14 or the X-ray partial beams 15 have an opening angle of 2β. Respectively. The X-ray partial beams 15 extend on both sides of the specialist center plane 20, each with a half aperture angle β. This is illustrated in FIG. 4, wherein in the illustration of FIG. 4 the normal plane 24 lies in the plane of the drawing.
    The X-ray beam 14 serves to illuminate the examination object 12 along an axis 30, whereby e.g. A computed tomography method can be carried out to produce at least one sectional image of the examination object 12. In accordance with the different angles of the angles 18, the partial ray rays 15 have different directions of incidence 19. The sectional image should reflect the structure of the examination object 12 in the sectional plane of the X-ray Fåcher beam 14 with the examination object 12, the sectional plane essentially corresponding to the specialist center plane 20.
    In conventional computed tomography methods, only the weakening experienced by the examination object 12 going to the X-ray partial beams 15 is determined. That it is specifically detected only the unscattered or weak Rontgen radiation 17. In this case absorption profiles are recorded (for many different rotational positions of the examination object 12) from which the sectional image is calculated by means of mathematical methods known per se which are based on the filtered back projection.
    The device 7 according to the invention or the method according to the invention is, of course, also suitable for detecting exclusively weak X-ray radiation 17. However, by means of the device according to the invention the scattered X-ray radiation 16 is also detected
    Detection sensitivity can be further increased, whereby a higher resolution can be achieved and / or the dose burden for the examination object 12 can be reduced.
    As illustrated in FIG. 6, the detector elements 11 of the device 7 are arranged along a line 21 so that the individual detector elements 11 detect X-ray partial beams 15 with different fan angles 18. Between the individual detector elements 11 no diaphragms or Kollimatorsepten are arranged. Correspondingly, the detector elements 11 detect not only the unscattered X-ray partial beams 15 or not only the weak X-ray radiation 17 but also scattered X-ray radiation 16 resulting from scattering of portions of individual X-ray partial beams 15 in the examination subject 12. In this respect, the detector elements 11 can also be regarded as "primary" detector elements, for which reason the three detector elements 11 shown in FIG. 6 are numbered 1 to 3 along the line 21 with Dpj, j.
    Due to the absence of collimator septa, the areas of the primary detector elements 11 can be increased in comparison to known solutions, which contributes significantly to the possibility of reducing the dose load. By determining the scattered radiation 16, an image quality can be achieved that is at least as high as in conventional solutions.
    The detector elements 11 'of the second device 7' are arranged along lines 22. In the illustrated exemplary embodiment, the lines 21, 22 all run straight and parallel to one another and lie in the same plane, wherein the examination object 12 is arranged between this plane and the X-ray source 13. The lines 22 are seen along the axis 30 and seen in the directions of incidence 19 as compared to the line 21 accordingly offset laterally, i. the detector elements 11 'are offset laterally relative to the detector elements 11. In the illustration of FIG. 6, the lines 22 run to the left of line 21. Correspondingly, in the normal plane 24 there are spacing angles 23 between the line 21 and the nearest line 22 and between the two lines 22, the distance angles 23 assuming different values, see. Fig. 4.
    The sensitive areas of the detector elements 11, 11 'are formed by the respective absorber elements 1, which in the illustrated exemplary embodiment have a substantially quadratic surface.
    In the exemplary embodiment of FIGS. 4-6, the detector elements 11 'serve to detect scattered X-ray radiation 16, but not unscrewed, weak X-ray radiation 17. In this respect, the detector elements 11' can also be regarded as "secondary" detector elements 6 are numbered with Dsmn, where m is from 1 to 2 and refers to the respective line 22 and where n goes from 1 to 3 and the detector elements 11 'along one of the lines 22 numbered.
    In Fig. 6, the scattered X-ray radiation 16 resulting from that X-ray partial beam 15 incident on the detector element Dpi is illustrated by a dashed circle around the detector element Dpi. This is based on the assumption that the scattered X-ray radiation 16 is rotationally symmetrical about the Rontgen partial beam 15 causing it. Accordingly, a portion SI of said X-ray scattered radiation 16 which is scattered into the detector element Dp2 is the same size as a portion S2 which is scattered in the detector element Dsll.
    Similarly, the scattered X-ray radiation 16 resulting from that X-ray partial beam 15 is incident on the detector element
    Dp3 hits, illustrated by a dashed circle around the detector element Dp3. Due to the assumed rotational symmetry, a proportion S3 of said X-ray scattered radiation 16 which is scattered into the detector element Dp2 is equal to a proportion S4 which is scattered into the detector element Dsll.
    The detector elements Dpi and Dp3 are the nearest neighbors of the detector element Dp2. It goes without saying that the above considerations can be carried out in a completely analogous way also for the nearest neighbors or for neighbors with higher orders. By detecting the corresponding scattering components with the detector elements 11 ', the radiation measured in the detector elements 11 can be corrected arithmetically, so that finally only the unscattered, weak X-ray radiation 17 that has fallen onto the detector elements 11 can be determined approximately.
    The concrete arithmetic as well as weighting factors result fundamentally from the geometry of the detector elements 11, 11 'used. Furthermore, arithmetic and weighting factors may be derived and adapted from a spatial modeling of the ray paths.
    If only the nearest neighbors are taken into account in the illustrated exemplary embodiment with geometrically identically designed detector elements 11, 11 ', this represents a first approximation. In the exemplary embodiment of FIG. 6 thus shown, an intensity Id (Dp2) of the unscattered, weak X-ray radiation has been obtained 17 in the detector element Dp2 as
    Id (Dp2) = I (Dp2) - S2 - S4, where I (Dp2) is the intensity measured overall in the detector element Dp2, i. the sum of scattered Rontgen radiation 16 and unscattered, weak Rontgen radiation 17 is.
    In order to ensure that each detector element Dsmn measures only the "correct" scatter proportion and no superposition of scattered X-radiation 16 of a plurality of X-ray partial beams 15, Kollimatorsepten 31 are provided between those detector elements 11 'of the second device 7', the different Rontgen partial beams 15th or different Fåcherwinkeln 18 can be assigned.
    FIGS. 7 and 8 relate to a further exemplary embodiment of an arrangement for determining X-ray radiation 16 scattered in the examination subject 12 and unscattered weak Rontgen radiation 17, which is basically completely analogous to the arrangement of FIGS. 4-6. In addition, however, the first device 7 has detector elements 11 along a further line 21 '. Analogously, the second device 7 'further lines 22'.
    As illustrated in FIG. 8, all the lines 21, 21 ', 22, 22' run straight and parallel to one another and lie in the same plane. The further line 21 'is arranged in the illustration of FIG. 8 to the right of the line 21 and the other lines 22' to the right of the further line 21 '. Accordingly, in the normal plane 24 further distance angles 23 'result between the further line 21' and the next further line 22 'and between the further lines 22', wherein the further distance angles 23 'are of different sizes, cf. Fig. 7.
    The nomenclature for the detector elements 11, 11 'is basically the same in Fig. 8 as in Fig. 6, but for all detector elements 11, 11' located on the left side there is additionally provided a " 1 " all detector elements 11, 11 ', which are located on the right side, in addition, an "r".
    In addition, the detector elements 11, 11 'of the lines 21', 22 'have an offset angle relative to the detector elements 11, 11' of the lines 21, 22 in the mid-plane of the mid-plane 20.
    Correspondingly, in the illustration of FIG. 8, the detector elements 11, 11 'of the lines 21', 22 'are offset upwards relative to the detector elements 11, 11' of the lines 21, 22. As a result, a better spatial resolution is achieved or doubled.
    The equations for the subtraction of the scattered radiation components now have to take into account both lines 21, 21 ', which, given the same geometrical design of the detector elements 11, 11', e.g. (the designation of the intensities follows the nomenclature used in the discussion of FIG. 6 above):
    Id (Dpl I) = I (Dpl I) - 2 * [I (Dsl21) - [I (Dsr22) + I (Dsr32)] / 2] - [I (Dsl32) - [I (Dsr33) + I (Dsr43)] / 2] - [I (Dsr31) + I (Dsr41)] / 2 - [I (Dsl43) - [I (Dsr44) + I (Dsr54)] / 2] - [I (Dsr42) + I (Dsr52)] / 2 - I (Dsl54) - I (Dsr53) / 2 - [sqrt (1, 25) - 1] * [[I (Dsrll) + I (Dsr21)] / 2 - I (Dsll2)] - [2 - sqrt (1,25)] * [[I (Dsrl2) + I (Dsr22)] * 12 - I (Dsll3)] - [sqrt (3,25) -1] * [I (Dsr31) - [I (Dsl22 ) + I (Dsl32)] / 2] - [2 - sqrt (3,25)] * [I (Dsr32) - [I (Dsl23) + I (Dsl33)] / 2]] - [sqrt (7,25 ) -2] * [I (Dsr42) - [I (Dsl33) + I (Dsl43)] / 2] - [3-sqrt (7.25)] * [I (Dsr43) - [I (Dsl34) + I (Dsl44)] / 2] - [sqrt (7.25) -2] * [I (Dsr42) - [I (Dsl33) + I (Dsl43)] / 2] - [3 - sqrt (7.25)] * [I (Dsr43) - [I (Dsl34) + I (Dsl44)] / 2].
    9 finally shows a schematic detail view of devices 7, 7 'according to the invention of a further embodiment of the arrangement according to the invention. The detector elements 11 of the first device 7 are arranged in two dimensions along an x-direction and a y-direction in a first plane 26. The detector elements 11 'of the second device 7' are also arranged two-dimensionally along the x-direction and the y-direction in a second plane 27.
    The planes 26, 27 have, seen in a normal direction on the planes 26, 27 normal direction 28 at a distance 32 to each other. In the process, some of the X-ray partial beams 15 can also strike the detector elements 11, 11 'in the normal direction 28, ie. An incident direction 19 may be parallel to the normal direction 28. The detector elements 11 are located in the upper plane 26 ("up"), which is arranged closer to the examination object 12. The detector elements 11 'are located in the lower plane 27 ("low"), which is located farther away from the examination subject or from the Rontgen source 13 as seen from the plane 26. Accordingly, the detector elements 11 are numbered in Fig. 9 with Duxy and the detector elements 11 'with Dixy.
    The detector elements 11 are arranged in such a rasterformige in the first plane 26 that result Liicken 29. When viewed in the normal direction 28, the detector elements 11 'are arranged in these gaps 29. The detector elements 11 thus act as diaphragms for the detector elements 11 '. The distance 32 is chosen in relation to the size of the individual detector elements 11 'such that the detector elements 11' can only be achieved by unscattered, weak X-ray partial beams 15. In contrast, both the scattered X-ray radiation 16 and the unscattered, weak X-ray radiation 17 impinge into the detector elements 11.
    In this case as well, mathematically, the intensity Id (Duxy) can be determined at least approximately, which corresponds only to the intensity of the unscattered, weak Rontgen radiation 17 in the detector element Duxy. For example, the detector elements 11, 11 'directly adjacent to the detector element Duxy considered can be considered for this purpose. In the arrangement shown in FIG. 9, two cases then arise: a) The detector element Duxy has two adjacent Dl neighbors and six adjacent Du neighbors. b) The Duxy detector element has four adjacent Dl neighbors and four adjacent Du neighbors. The areas of the detector elements 11, 11 'are assumed to be the same size. Then, for a)
    Id (Duxy) = I (Duxy) - 1/7 * (I (Duxy) + I (Dux (y + 1)) + I (Dux (yl)) + I (Du (xl) (y-1)) + I (Du (xl) (y + 1)) + I (Du (x + 1) (y-1)) + I (Du (x + 1) (y + 1)) - 7 * (I (Dl (xl) y) + I (Dl (x + 1) y)) / 2 or
    Id (Duxy) = I (Duxy) - 1/7 * (I (Duxy) + I (Du (x + 1) y) + I (Du (x + 1) (y + 1)) + I (Du ( xl) y) + I (Du (xl) (y + 1)) + I (Du (xl) (y-1)) + I (Du (x + 1) (y-1)) - 7 * (I. (Dlx (y + 1)) + I (Dlx (y-1))) / 2 and for b)
    Id (Duxy) = I (Duxy) - 1/5 * (I (Duxy) + I (Du (x + 1) y) + I (Du (x + 1) (y + 1)) + I (Du ( xl) y) + I (Du (x-1) (y + 1)) + I (Du (xl) (y-1)) + I (Du (x + l) (y-1)) - 5 * (I (Dlx (y + 1)) + I (Dlx (yl)) + I (Dl (x + 1) y) + I (Dl (xl) y)) / 4)
    In this case, I (Duxy) denotes the total intensity measured in the detector element Duxy (i.e., the intensity sum of scattered X-ray radiation 16 and untreated X-ray radiation 17) and I (Dlxy) the measured intensity in the detector element Dlxy (only unscattered X-ray radiation 17). That it is enough to arrange the detector elements 11, 11 'only in two planes, which is particularly friendly to production engineering.
    It should be noted that it is clearly mathematically obvious more possibilities to determine a Schätzwert from a set of malfunctioned measured values, such as mean minus median differences, etc. The above arithmetic is therefore to be understood as purely exemplary to the inventive approach to make comprehensible: the weak useful signal has a higher spatial frequency than the
    Stray radiation component, therefore, the scattered radiation component does not actually have to be measured for each point.
    REFERENCE LIST 1 absorber element 2 nanowire 3 voltage source
    4 Thermally insulated vessel 5 Be window 6 Evaluation and control unit 7, 7 'Device 8 Ohmic resistance 9 Comparator 10 Flip-flop 11, 11' Detector element 12 Object to be examined 13 X-ray source 14 X-ray beam 15 X-ray beam 16 Scattered radiation 17 Unscattered resp Radiation 18 Angle 19, 19 'Direction of incidence 20 center of expertise 21, 21' Line of the detector elements of the first device 22, 22 'Line of the detector elements of the second device 23, 23' Distance angle 24 Normal plane 25 Series resistor 26 First level 27 Second level 28 Normal direction 29 Gap 30 axis 31 collimator seam 32 distance between first and second plane 33 support 34 cold bath T temperature of the nanowire
    Tc transition temperature
    Rn Electrical resistance of the nanowire t Time iH heating current
    Ix intensity of the incident on the absorber element
    X-ray radiation 2β aperture angle
    权利要求:
    Claims (24)
    [1]
    ansprOche
    1. Device (7) for detecting radiation, preferably X-ray radiation, the device comprising at least one detector element (11) which has an absorber element (1) for the radiation and a nanowire (2) which is thermally conductively connected to the absorber element (1) of a superconducting material, wherein cooling means (34) are provided, in an operating state of the device (7) the absorber element (1) and the nanowire (2) of the at least one detector element (11) to a temperature in the region of the transition temperature of the nanowire (2) to cool, and wherein an evaluation and control unit (6) for determining whether the nanowire (2) of the at least one detector element (11) is in a superconducting state or not, is provided, characterized in that at least one Mitteis the evaluation and control unit (6) controllable heating means (8) is provided to the absorber element (1) of the at least one detector element (11) a thermisc The evaluation and control unit (6) is designed to continuously supply energy pulses to the absorber element (1) of the at least one detector element (11) in the operating state of the device (7), as long as the nanowire (2) the at least one detector element (11) is in the superconducting state.
    [2]
    2. Device (7) according to claim 1, characterized in that as the at least one heating means, an ohmic resistance (8) is provided, which is thermally conductively connected to the absorber (1) of the at least one detector element (11).
    [3]
    3. Device (7) according to one of claims 1 to 2, characterized in that a current source is provided in the operating state of the device (7) the nanowire (2) of the at least one detector element (11) in the range of 70% to 99 %, preferably in the range of 80% to 95% of its critical current density.
    [4]
    4. Device (7) according to any one of Anspriiche 1 to 3, characterized in that the at least one detector element (11) in a thermally insulated GefäB (4) is arranged, which has a window (5) for the radiation to be detected.
    [5]
    5. Device (7) according to one of claims 1 to 4, characterized in that the nanowire (2) of the at least one detector element (11) is made of niobium nitride or tantalum nitride.
    [6]
    6. Device (7) according to one of Anspriiche 1 to 5, characterized in that the absorber element (1) of the at least one detector element (11) is made of bismuth.
    [7]
    7. Device (7) according to one of claims 1 to 6, characterized in that the absorber element (1) of the at least one detector element (11) is deposited on the nanowire (2) of the at least one detector element.
    [8]
    8. Device (7) according to one of Anspriiche 1 to 7, characterized in that a plurality of detector elements (11) are provided.
    [9]
    9. Apparatus according to claim 8, characterized in that the detector elements (11) along at least one line (21), preferably along several lines (21, 21 '), particularly preferably along a plurality of parallel lines (21, 21') are arranged.
    [10]
    10. Arrangement for determining radiation (16) and weak radiation (17) scattered in an examination object (12), the arrangement comprising a radiation source (13) for generating a fan beam (14) with partial beams (15) having different fan angles (18) for illumination of the examination object (12) under different directions of incidence (19) lying in a specialist center plane (20), the arrangement further comprising a first device (7) according to any one of claims 8 to 9 and a second device (7 ') according to any one of Claims 8 to 9, wherein at least a part of the detector elements (11) of the first device (7) in the directions of incidence (19) seen behind the examination subject (12) is arranged and wherein at least a part of the detector elements (11 ') of the second device ( 7 ') parallel to a radiation source (13) and the object to be examined (12) connecting axis (30) seen laterally offset from the detector elements (11) de r first device (7) is arranged.
    [11]
    11. Arrangement according to claim 10, characterized in that the detector elements (11) of the first device (7) along a line (21), which is preferably in the specialist center plane (20) are arranged, that the detector elements (11 ') of second device (7 ') along several lines (22) are arranged and that of the radiation source (13) seen from the lines (22) of the detector elements (11') of the second device (7 ') alternately to each other and preferably to the line ( 21) of the detector elements (11) of the first device (7) have a distance angle (23) which is measured in a normal plane (24) that is normal to the median center plane (20).
    [12]
    12. Arrangement according to claim 11, characterized in that the course of the several lines (22) of the detector elements (11 ') of the second device (7') the course of the line (21) of the detector elements (11) of the first device (7) essentially follows.
    [13]
    13. Arrangement according to one of claims 11 to 12, characterized in that the detector elements (11) of the first device (7) are additionally arranged along a further line (21 ') such that the detector elements (11') of the second device (7 ') are additionally arranged along further lines (22') and that from the radiation source (13) seen from the other lines (22 ') of the detector elements (11') of the second device (7 ') alternately to each other and preferably to the further line (21 ') of the detector elements (11) of the first device (7) have a further distance angle (23') which is measured in the normal plane (24).
    [14]
    14. Arrangement according to claim 13, characterized in that the detector elements (11) of the first device (7) between the detector elements (11 ') of the second device (7') are arranged.
    [15]
    15. An arrangement according to any one of claims 13 to 14, characterized in that the course of the further line (21 ') of the detector elements (11) of the first device (7) the course of the line (21) of the detector elements (11) of the first device (7) essentially follows and that the course of the further lines (22 ') of the detector elements (11') of the second device (7 ') corresponds to the course of the further line (21') of the detector elements (11) of the first device (7). essentially follows.
    [16]
    16. Arrangement according to one of claims 13 to 15, characterized in that, viewed from the radiation source (13), the detector elements (11) of the line (21) and the further line (21 ') of the first device (7) have an offset angle to one another which is measured in the mid-stroke plane (20).
    [17]
    17. Arrangement according to claim 16, characterized in that from the radiation source (13) seen from the detector elements (11 ') of the lines (22) and the further lines (22') of the second device (7 ') have the offset angle to each other.
    [18]
    18. Arrangement according to one of claims 11 to 17, characterized in that only between detector elements (11 ') of the second device (7') Kollimatorsepten (31) are provided, wherein the Kollimatorsepten (31) preferably between detector elements (11 ') of the second device (7 ') are arranged, which along one of the lines (22) and / or the further lines (22') are arranged consecutively.
    [19]
    19. Arrangement according to claim 10, characterized in that the detector elements (11) of the first device (7) in a first plane (26) are arranged on a two-dimensional grid, that the detector elements (11 ') of the second device (7') in a second plane (27) parallel to the first plane (26), which is arranged behind the first plane (26) as viewed from the radiation source (13), and that in one of the two planes (26, 27) is normal standing normal direction (28), the detector elements (11 ') of the second device (7') in gaps (29) between the detector elements (11) of the first device (7) are arranged.
    [20]
    20. The arrangement according to claim 19, characterized in that a third device according to one of claims 8 to 9 is provided, the detector elements are arranged in a third plane which is parallel to the first plane (26) and second plane (27) and between the first Plane (26) and second plane (27) is arranged, wherein the detector elements of the third device in the normal direction (28) seen from the detector elements (11) of the first device (7) are covered.
    [21]
    21. A method for detecting radiation, preferably X-ray radiation, wherein an absorber element (1) and a nanowire (2) thermally conductively connected to the absorber element (1) are made from a superconducting material to a temperature in the region of the transition temperature of the nanowire (2). in which the radiation is absorbed by the absorber element (1) and it is constantly determined whether the nanowire (2) is in a superconducting state or not, characterized in that a heating means (8) runs along the absorber element (1) Energy pulses are supplied, as long as the nanowire (2) is in the superconducting state, and thereby the power supplied to the absorber element (1) is determined.
    [22]
    22. Method for determining radiation (16) and weak radiation (17) scattered in an examination object (12), the examination object (12) being illuminated with a fan beam (14) with partial beams (15) having different fan angles (18), in which a sum of partial beams (15) weakened in the examination subject (12) and scattered radiation (16) is measured by means of a method according to claim 21, wherein the measurement takes place in at least one dimension in a spatially resolved manner such that the individual partial beams (15) are spatially resolved.
    [23]
    23. The method according to claim 22, characterized in that mitteis another method according to claim 21 exclusively scattered radiation (16) is measured, wherein the measurement in at least one dimension spatially resolved takes place at least at such locations, in which at an assumed rotationally symmetrical spatial distribution The scattered radiation (16) of each partial beam (15) would be scattered the same proportion of the respective partial beam (15) as in a location at which a weakened partial beam (15) adjacent to the respective partial beam (15) is measured.
    [24]
    24. The method according to claim 23, characterized in that for the locations where the weakened partial beams (15) are measured, the exclusively weakened radiation (17) is computationally determined, in each case by the measured sum of weakened radiation (17) and scattered radiation (16) corresponding parts of the measured exclusively scattered radiation (16) are deducted.
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    同族专利:
    公开号 | 公开日
    WO2017005602A1|2017-01-12|
    US10310096B2|2019-06-04|
    US20190072675A1|2019-03-07|
    AT517438B1|2018-10-15|
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    法律状态:
    2021-03-15| MM01| Lapse because of not paying annual fees|Effective date: 20200707 |
    优先权:
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    ATA50587/2015A|AT517438B1|2015-07-07|2015-07-07|DEVICE AND METHOD FOR DETECTING RADIATION|ATA50587/2015A| AT517438B1|2015-07-07|2015-07-07|DEVICE AND METHOD FOR DETECTING RADIATION|
    US15/742,207| US10310096B2|2015-07-07|2016-06-30|Device and method for detecting radiation|
    PCT/EP2016/065328| WO2017005602A1|2015-07-07|2016-06-30|Device and method for detecting radiation|
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