CN115831432A - Neutron polarization turning device and turner - Google Patents
Neutron polarization turning device and turner Download PDFInfo
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- CN115831432A CN115831432A CN202211528470.6A CN202211528470A CN115831432A CN 115831432 A CN115831432 A CN 115831432A CN 202211528470 A CN202211528470 A CN 202211528470A CN 115831432 A CN115831432 A CN 115831432A
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Abstract
A neutron polarization flipping device, comprising: the guide magnet is used for generating a guide magnetic field in a preset area; the overturning assembly comprises an overturning support, a first coil and a second coil, the first coil and the second coil are wound on the overturning support to be arranged in a preset area, the driving device is used for receiving a target shooting control signal of the accelerator and then outputting current to the first coil to generate a compensation magnetic field opposite to the guiding magnetic field, the guiding magnetic field and the compensation magnetic field form a demagnetizing field area in an intersecting area, and the driving device is further used for outputting current to the second coil to generate a precession magnetic field orthogonal to the guiding magnetic field and the compensation magnetic field in the demagnetizing field area. The polarization upset of neutron is realized to larmor precession based on neutron for neutron polarization turner simple structure realizes conveniently, and the upset speed is fast, and can receive behind the target practice control signal of accelerator, and carry out the neutron upset along with target practice control signal. The invention also provides a neutron polarization inverter.
Description
Technical Field
The invention relates to the technical field of neutron polarization overturning, in particular to a neutron polarization overturning device and an overturning device.
Background
Neutrons have the characteristics of no electricity, magnetic moment and strong penetrability, can distinguish light elements, isotopes and adjacent elements, and are a powerful means for exploring the microstructure of substances. The polarized neutrons will further exert their advantages and be widely applied in many fields such as condensed physical and chemical, nano material, protein and biological, industrial nondestructive deep flaw detection, etc. In a polarized neutron experiment, the polarization of neutrons needs to be reversed to measure the proportion of different polarization states of the neutrons in the total beam current, which is necessary for calculating the neutron polarizability.
The device for realizing the polarization inversion of the neutrons is called a polarization inverter and is used for changing the relative angle between the spins of the neutrons and the guiding magnetic field of the neutrons. Based on different realization principles, the polarization inverter includes pi polarization inverter, RF polarization inverter, etc., but these polarization inverters are all relatively complicated to realize, and the turnover speed is slow, for example, in a common polarization inverter, it provides the low temperature environment in vacuum for the superconducting diamagnetic body subassembly through the vacuum thermostat for the superconducting diamagnetic body subassembly forms a layer of meissner diamagnetic layer in the vacuum thermostat. Then two guiding magnetic fields with opposite magnetic field directions are formed on two sides of the Meissner diamagnetic layer, and the guiding magnetic fields are used for guiding the polarization of neutrons passing through the guiding magnetic fields and enabling the polarization of the neutrons passing through the Meissner diamagnetic layer to be reversed. Because the polarization inverter needs to provide a vacuum low-temperature environment for the superconducting diamagnetic body component, the realization is complex, the realization cost is high, and the inversion speed is slow.
Disclosure of Invention
The invention mainly solves the technical problems of complex realization, high realization cost and low overturning speed of the polarization overturning device.
According to a first aspect, there is provided in an embodiment a neutron polarization flipping device, comprising:
a guide magnet for generating a guide magnetic field in a preset region;
the overturning assembly comprises an overturning bracket, a first coil and a second coil, the first coil and the second coil are wound on the overturning bracket to be arranged in the preset area,
the driving device is used for outputting current to the first coil to generate a compensation magnetic field opposite to the guiding magnetic field and enable the guiding magnetic field and the compensation magnetic field to form a demagnetizing field area in an intersecting area, and the driving device is also used for outputting current to the second coil to enable a precession magnetic field orthogonal to the guiding magnetic field and the compensation magnetic field to be generated in the demagnetizing field area, and the precession magnetic field is used for carrying out polarization overturning on neutrons entering the precession magnetic field.
According to a second aspect, there is provided in an embodiment a neutron polarization inverter comprising:
a guide magnet for generating a guide magnetic field in a preset region;
the overturning assembly comprises an overturning bracket, a first coil and a second coil;
the first coil and the second coil are wound on the overturning support to be arranged in the preset area, the first coil is used for generating a compensation magnetic field opposite to the guide magnetic field after being electrified so as to enable the guide magnetic field and the compensation magnetic field to form a demagnetizing field area in an intersecting area, the second coil is used for generating a precession magnetic field orthogonal to the guide magnetic field and the compensation magnetic field in the demagnetizing field area after being electrified, and the precession magnetic field is used for polarizing and overturning neutrons entering the second coil.
In some embodiments, the guidance magnets comprise a first set of magnets and a second set of magnets;
the first group of magnets and the second group of magnets are oppositely arranged on two sides of the preset area, and the first group of magnets and the second group of magnets are arranged in parallel, so that a guide magnetic field generated in the preset area between the first group of magnets and the second group of magnets is a uniform magnetic field.
In some embodiments, the guidance magnet further comprises a first set of magnet holders and a second set of magnet holders;
first group magnet and second group magnet all include a plurality of magnet, first group magnet support and second group magnet support all seted up a plurality ofly with the mounting groove that magnet matches, it is a plurality of the mounting groove of first group magnet support and second group magnet support is located respectively to magnet, in order to form respectively first group magnet with second group magnet.
In some embodiments, the turning bracket comprises two horizontal winding columns parallel to each other and two vertical winding columns perpendicular to the horizontal winding columns respectively;
the first coil is wound on the two horizontal winding columns in a direction perpendicular to the horizontal winding columns, the second coil is wound on the two vertical winding columns in a direction perpendicular to the vertical winding columns, and the two vertical winding columns are respectively arranged in parallel with the first group of magnets and the second group of magnets.
In some embodiments, two horizontal winding columns or two vertical winding columns extend to form a mounting block exposed out of the turnover bracket, and the mounting block is used for mounting and fixing the turnover bracket.
In some embodiments, the current output by the driving device received by the second coil when the polarization of the neutron is reversed once is changed to generate the precession magnetic field with a changed magnetic field intensity, and the rate of change of the magnetic field intensity is smaller than a preset value.
In some embodiments, the magnetic field strength of the precession magnetic field is changed from an initial magnetic field strength to a predetermined magnetic field strength, and then from the predetermined magnetic field strength to the initial magnetic field strength.
In some embodiments, the second coil is configured to receive an electric current output by the driving device when neutrons are emitted to the precessional magnetic field to generate the precessional magnetic field.
In some embodiments, the turning device further comprises two support plates and four mounting brackets, wherein one end of two of the mounting brackets clamps one end of one of the support plates, the other end of two of the mounting brackets clamps one end of the other support plate, one end of the other two of the mounting brackets clamps the other end of one of the support plates, the other end of the other two of the mounting brackets clamps the other end of the other support plate, the guiding magnet is fixed between the two support plates, and the turning bracket is fixed on at least one of the mounting brackets.
According to the neutron polarization inverter and the neutron polarization inverting device in the embodiments, the guiding magnetic field in the preset area is generated by the guiding magnet, then the inverting component is arranged on the body of the guiding magnetic field, and the first coil generates a compensation magnetic field opposite to the guiding magnetic field, so that the compensation magnetic field is counteracted with the compensation magnetic field and a demagnetizing field area is formed. And then the second coil generates a precession magnetic field orthogonal to the guide magnetic field and the compensation magnetic field, the polarization inversion of the neutrons is realized through Larmor precession of the neutrons, and the polarization inversion of the neutrons is realized through the polarization precession of the neutrons in a demagnetizing field area. Because only the guide magnet, the first coil and the second coil are needed to generate a guide magnetic field, a compensation magnetic field and a precession magnetic field respectively, the polarization overturning of neutrons can be realized based on Larmor precession of the neutrons, so that the neutron polarization overturning device is simple in structure and convenient to realize. And after the first coil and the second coil are electrified, a magnetic field for neutron polarization reversal can be generated, so that the reversal speed is improved.
Drawings
FIG. 1 is a structural schematic of a neutron polarization inverter;
FIG. 2 is a schematic view of another embodiment of a guidance magnet;
FIG. 3 is a schematic structural view of an embodiment of a roll-over stand;
FIG. 4 is a block diagram of a neutron polarization flipping mechanism of an embodiment;
fig. 5 is a schematic diagram illustrating a variation of an output current of the driving apparatus according to an embodiment.
Detailed Description
The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.
Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the description of the methods may be transposed or transposed in order, as will be apparent to a person skilled in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.
The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).
In the embodiment of the invention, the continuous guide magnetic field is generated by the guide magnet, then the compensation magnetic field and the precession magnetic field which are required during neutron polarization inversion are respectively generated by the first coil and the second coil, and then the polarization inversion of neutrons is realized based on Larmor precession of neutrons.
Referring to fig. 1, some embodiments provide a neutron polarization inverter that includes a steering magnet 10 and an inversion assembly, described in detail below.
The guidance magnet 10 serves to generate a guidance magnetic field in a predetermined region. In some embodiments, the guidance magnetic field generated by the guidance magnet 10 in the predetermined region is a uniform magnetic field, and the guidance magnetic field is used for guiding the polarization vector of the neutron in the guidance magnetic field, and the polarization vector of the neutron is always in parallel or anti-parallel relation with the guidance magnetic field.
Referring to fig. 1 and 2, in some embodiments, the guidance magnet 10 includes a first set of magnets 12 and a second set of magnets 12a. The first set of magnets 12 and the second set of magnets 12a are oppositely disposed at two sides of the predetermined region, or the region between the first set of magnets 12 and the second set of magnets 12a is the predetermined region, and the first set of magnets 12 and the second set of magnets 12a are disposed in parallel, so that the guiding magnetic field generated in the predetermined region between the first set of magnets 12 and the second set of magnets 12a is a uniform magnetic field. In some embodiments, the poles of the first set of magnets 12 and the poles of the second set of magnets 12a are oppositely disposed, i.e., the N-pole of the first set of magnets 12 is opposite to the S-pole of the second set of magnets 12a, and the S-pole of the first set of magnets 12 is opposite to the N-pole of the second set of magnets 12a, such that the guiding magnetic field generated between the first set of magnets 12 and the second set of magnets 12a is a uniform magnetic field. In some embodiments, the first set of magnets 12 and the second set of magnets 12a may be permanent magnets or electromagnets, and since the guiding magnetic field needs to be stable for a long time, the first set of magnets 12 and the second set of magnets 12a are usually implemented by using permanent magnets, such as MdFeB magnets.
In some embodiments, the guidance magnet 10 further includes a first set of magnet holders 14 and a second set of magnet holders 14a, and the first set of magnets 12 and the second set of magnets 12a each include a plurality of magnets 122 and are each formed by splicing together a plurality of magnets 122. In this embodiment, the first set of magnet holders 14 and the second set of magnet holders 14a may be identical in structure, and the first set of magnets 12 and the second set of magnets 12a may be identical in structure, and therefore the first set of magnet holders 14 and the first set of magnets 12 are described.
The first set of magnet holders 14 are formed with a plurality of mounting slots 142 that are matched with the magnets 122, and the plurality of magnets 122 are respectively disposed in the mounting slots 142 of the first set of magnet holders 14 to form the first set of magnets 12. In some embodiments, the mounting slots 142 are arranged in a compact manner, so that the magnets 122 can be mounted and placed in the first set of magnet holders 14 through the mounting slots 142, and can form a larger magnet together with the adjacent magnets 122. For example, the mounting groove 142 is a bar shape, the magnet 122 is a corresponding bar magnet, the mounting groove 142 and the mounting groove 142 are arranged in a compact and parallel manner, and a plurality of bar magnets are respectively placed in different mounting grooves 142 to form a larger magnet. In this embodiment, since the first group of magnets 12 and the second group of magnets 12a are formed by splicing a plurality of magnets 122, the strength and the coverage range of the guiding magnetic field generated between the first group of magnets 12 and the second group of magnets 12a are determined by the number of the spliced magnets 122, that is, the larger the number of the spliced magnets 122, the stronger the guiding magnetic field, and the larger the coverage range. Therefore, different numbers of magnets 122 can be arranged to form the first group of magnets 12 and the second group of magnets 12a with different sizes, so that guiding magnetic fields with different strengths and coverage ranges can be formed to adapt to different use occasions.
In some embodiments, the guidance magnet 10 further includes a first protective shell 16 and a second protective shell 16a. After the plurality of magnets 122 are placed on the first and second sets of magnet holders 14 and 14a, the first and second sets of magnet holders 14 and 14a may be covered by the first and second protective cases 16 and 16a, respectively, so as to cover the mounting grooves 142 of the first and second sets of magnet holders 14 and 14a and press the magnets 122 on the first and second sets of magnet holders 14 and 14a. In this embodiment, the first protective shell 16 and the second protective shell 16a are added, so that not only the magnet 122 on the bracket can be protected, but also the magnet 122 on the bracket can be fixed, and the movement of the position of the magnet 122 can be avoided. In this embodiment, the first protective case 16, the second protective case 16a, the first group magnet holder 14, and the second group magnet holder 14a are made of aluminum, and the first protective case 16 and the second protective case 16a may be fixed to the first group magnet holder 14 and the second group magnet holder 14a by screws, respectively.
Referring to fig. 3, the flipping unit includes a flipping frame 20, and a first coil and a second coil (not shown) wound on the flipping frame 20.
In some embodiments, the flip frame 20 includes two parallel horizontal winding posts 22 and two vertical winding posts 26 perpendicular to the horizontal winding posts 22, and the two vertical winding posts 26 are disposed parallel to the first and second sets of magnets 12 and 12a, respectively. In this embodiment, the first coil is wound on the two horizontal winding posts 22 in a direction perpendicular to the horizontal winding posts 22, so that when the wound first coil is energized, the compensation magnetic field generated inside the wound first coil is not only a uniform magnetic field, but also a direction parallel to the horizontal winding posts 22, and the guidance magnetic field generated between the first set of magnets 12 and the second set of magnets 12a is also a uniform magnetic field, but a direction orthogonal to the first set of magnets 12 and the second set of magnets 12a, so that the compensation magnetic field and the guidance magnetic field are in the same horizontal direction, and can cancel each other to form a demagnetizing field area. Similarly, the second coil is wound around the two vertical winding posts 26 in a direction orthogonal to the vertical winding posts 26, so that when the wound second coil is energized, the precessional magnetic field generated inside it is not only a uniform magnetic field, but also in a direction parallel to the horizontal winding posts 22, so that the precessional magnetic field is orthogonal to the guidance magnetic field and the compensation magnetic field, respectively. In some embodiments, the two vertical winding posts 26 are not only disposed in parallel with the first and second sets of magnets 12 and 12a, respectively, but the two vertical winding posts 26, the first and second sets of magnets 12 and 12a are also located in the same line, and the two vertical winding posts 26 are located between the first and second sets of magnets 12 and 12a, so that the two vertical winding posts 26 are located within a predetermined area, such that the horizontal winding post 22, the first coil, and the second coil are also located within the predetermined area.
The first coil is wound around the flip bracket 20 in a spiral shape, and is used for generating a compensation magnetic field opposite to the guiding magnetic field after being electrified, and the guiding magnetic field and the compensation magnetic field form a demagnetizing field area in an intersecting area. Because the magnetic field intensity of the compensation magnetic field is the same as that of the guide magnetic field and the magnetic field direction is opposite, the guide magnetic field and the compensation magnetic field can be mutually cancelled in the crossed area, and a demagnetizing field area without the existence of the magnetic field is generated. The second coil is also spirally wound around the reversing bracket 20, and is used for generating precession magnetic fields orthogonal to the guiding magnetic field and the compensating magnetic field in a demagnetizing field area after being electrified, and the precession magnetic fields are used for performing polarization reversing on neutrons entering the precession magnetic fields. When the first coil is electrified to generate a compensation magnetic field opposite to the guide magnetic field, the second coil is electrified to generate precession magnetic fields orthogonal to the guide magnetic field and the compensation magnetic field in a demagnetizing field area, and therefore polarization inversion of neutrons is achieved through Larmor precession of the neutrons.
In the embodiment, the inversion assembly realizes the polarization inversion of neutrons through larmor precession of the neutrons, and the basic principle is that on the background of a guide magnetic field generated by the guide magnet 10, a compensation magnetic field opposite to the guide magnetic field is generated through the first coil, so that the compensation magnetic field is counteracted with the compensation magnetic field to form a demagnetizing field region. And then a precession magnetic field orthogonal to the guide magnetic field and the compensation magnetic field is generated by the second coil, so that the polarization inversion of neutrons is realized through the polarization precession of the neutrons in a demagnetizing field region. The turning angle is determined by the magnitude of the precession magnetic field, which is determined by the magnitude of the current flowing into the second coil. In this embodiment, because the flip assembly has a simple structure, the thickness of the flip assembly is usually only a few centimeters, which is very suitable for spectrometer wires with short length. In the embodiment, after the first coil and the second coil are electrified, a magnetic field for neutron polarization overturning can be generated, so that the overturning speed is improved, the overturning time can be only 40ms, and the overturning time is faster than that of other existing polarization overturns.
In some embodiments, since the turning bracket 20 is located in the predetermined region, the first coil and the second coil are both located in the predetermined region after being wound on the turning bracket 20, so as to generate a compensation magnetic field opposite to the guiding magnetic field and a precession magnetic field orthogonal to the guiding magnetic field and the compensation magnetic field, respectively. In other embodiments, portions of the flip frame 20 are located within the predefined area and the first and second coils are wound around the flip frame 20 located within the predefined area such that both the first and second coils are located within the predefined area.
In some embodiments, two horizontal winding posts 22 and two vertical winding posts 26 are integrally formed and form a square inverted support 20. For example, a square hollow groove is opened in the middle of one plate, so that four sides of the plate form two horizontal winding columns 22 and two vertical winding columns 26 respectively. In some embodiments, the two horizontal winding posts 22 and the two vertical winding posts 26 may be spliced together to form the turning bracket 20, and the two horizontal winding posts 22 and the two vertical winding posts 26 are fastened together by screws. In this embodiment, the turning bracket 20 is made of bakelite, which has high mechanical strength, good insulation, heat resistance, and corrosion resistance. In some embodiments, two horizontal winding posts 22 or two vertical winding posts 26 are extended to form a mounting block 26 exposed from the inverted bracket 20, and then the inverted bracket 20 is fixed by the mounting block 26.
Referring to fig. 1 again, in some embodiments, the neutron polarization inverter further includes two support plates 30 and four mounting brackets 40, wherein one end of one support plate 30 is held by one end of two mounting brackets 40, one end of the other support plate 30 is held by the other end of two mounting brackets 40, one end of the other mounting bracket 40 is held by the other end of one support plate 30, and the other end of the other mounting bracket 40 is held by the other end of the other support plate 30. In this embodiment, the two ends of the mounting bracket 40 are respectively provided with a clamping groove 42 matched with the thickness of the support plate 30, so that the support plate 30 can be better clamped through the matching of the two mounting brackets 40, and the two mounting brackets 40 after clamping can be connected by a connecting block and fixed through screws. In this embodiment, the mounting bracket 40 is made of bakelite, which has high mechanical strength, good insulation, heat resistance, and corrosion resistance. In this embodiment, the both sides of backup pad 30 are seted up respectively with the spacing groove 32 that mounting bracket 40 thickness matches, and when two mounting bracket 40 gripped backup pad 30, two mounting bracket 40 blocked in spacing groove 32 respectively to make the difficult removal in position of two mounting bracket 40. In some embodiments, the support plate 30 is made of carbon steel.
In some embodiments, the first and second sets of magnet holders 14 and 14a, respectively, of the guidance magnet 10 are fixed between two support plates 30. The opposite surfaces of the two support plates 30 are provided with a placing groove 34, and the two ends of the first group of magnet supports 14 and the second group of magnet supports 14a are respectively connected in the placing groove 34 between the two support plates 30, and are fixed by clamping the two support plates 30. In this embodiment, the roll-over stand 20 is fixed to at least one mounting bracket 40. The turning bracket 20 is mounted on the mounting bracket 40 through a mounting block and fastened by screws. The turning bracket 20 is fixed on at least one mounting bracket 40 through the mounting block, so that the stable mounting can be realized. In this embodiment, the installation structure for fixing the guidance magnet 10 and the turning assembly can be quickly constructed by clamping and installing the two support plates 30 and the four installation supports 40, and the installation is simple and the operation is convenient.
Referring to fig. 1 and 4, in some embodiments, a neutron polarization flipping device is provided, which includes a driving device 50 in addition to the neutron polarization flipping device in the above embodiments.
The driving device 50 is used for outputting current to the first coil, so that the first coil generates a compensation magnetic field opposite to the guiding magnetic field, and the compensation magnetic field and the guiding magnetic field are uniform magnetic fields with the same intensity. In some embodiments, the driving device 50 is further configured to output a current to the second coil such that the second coil generates a precessional magnetic field orthogonal to the guiding magnetic field and the compensating magnetic field, respectively, and the strengths of the compensating magnetic field and the precessional magnetic field are related to the magnitude of the current output by the driving device 50.
In some embodiments, the driving device 50 includes a signal generator 52 and a current amplifier 54. The signal generator 52 is configured to output a voltage signal, and the power amplifier is configured to generate a corresponding current signal to power the first coil and the second coil according to the voltage signal output by the signal generator 52. For example, the amplitude of the output of the signal generator 52 ranges from-10V to +10V, and the power amplifier correspondingly generates a current signal of 0A to 20A, so that the power amplifier acts as a voltage-controlled current source to change the output current as the output voltage of the signal generator 52 changes. The voltage signal for control is generated by the driving device 50 to control the current amplifier 54 to generate a current signal with a magnitude large enough to allow the first coil and the second coil to generate magnetic fields with corresponding strength.
In some embodiments, the driving device 50 is configured to output a constant current to the first coil, so that the compensation magnetic field generated by the first coil is a constant uniform magnetic field. In some embodiments, the driving device 50 is configured to output a constant current to the second coil, so that the precession magnetic field generated by the second coil has a constant intensity, and since the neutron flip angle entering the precession magnetic field is determined by the intensity of the precession magnetic field, the flip angle of the neutron is fixed when the intensity of the precession magnetic field is constant.
Referring to fig. 5, in some embodiments, the driving device 50 is configured to output a varying current to the second coil, so that the second coil generates a precession magnetic field with a varying intensity, and the intensity variation rate is smaller than a predetermined value, generally smaller than the precession velocity of the neutron. In this embodiment, since the spin direction and the magnetic field direction of the spin of the polarized neutron are changed during the transmission process, the neutron is transmitted adiabatically, that is, the neutron is transmitted from the guiding magnetic field to the precession magnetic field; however, since the angle is changed by larmor precession, and the included angle of the neutron spins and the direction of the magnetic field are not changed in the changing process, the angle is changed by adiabatic rotation, that is, the neutrons are overturned by the precession magnetic field. In this embodiment, when the precession magnetic field performs primary polarization inversion on the neutrons, the precession magnetic field changes from the initial magnetic field strength to the preset magnetic field strength, and then changes from the preset magnetic field strength to the initial magnetic field strength. For example, when the preset magnetic field strength is smaller than the initial magnetic field strength, that is, the precession magnetic field is decreased from the initial magnetic field strength to the preset magnetic field strength, and then is increased from the preset magnetic field strength to the initial magnetic field strength, so as to complete the one-time polarization inversion of the neutrons. Because the neutron upset angle that gets into precession magnetic field is decided by the intensity of precession magnetic field, consequently when the intensity of precession magnetic field changes, the upset angle of neutron also changes, for example when presetting magnetic field intensity and being less than initial magnetic field intensity, the neutron will overturn an angle relevant with initial magnetic field intensity earlier, when the precession magnetic field reduces to presetting magnetic field intensity by initial magnetic field intensity, the upset angle of neutron will turn round to an angle relevant with presetting magnetic field intensity, at last the precession magnetic field rises to initial magnetic field intensity again by presetting magnetic field intensity, then the upset angle of neutron will turn round again and turn round the angle relevant with initial magnetic field intensity, thereby realize that the neutron that turnover efficiency is greater than 99% overturns. In some embodiments, when the precession magnetic field changes from the initial magnetic field strength to the predetermined magnetic field strength and then from the predetermined magnetic field strength to the initial magnetic field strength, the magnetic field strength may be a uniform linear change or a non-uniform curvilinear change as long as the change rate is smaller than the precession speed of the neutron.
Referring to fig. 4 again, in some embodiments, the driving device 50 is configured to receive the target-shooting control signal of the accelerator and output a current to the first coil and the second coil. In this embodiment, the accelerator generates a targeting control signal and outputs the targeting control signal to the driving device 50 when emitting neutrons to the precession magnetic field, and then the driving device 50 outputs corresponding current to the first coil and the second coil according to the targeting control signal, so that the first coil and the second coil respectively generate a compensation magnetic field and a precession magnetic field only when neutrons are going to enter the precession magnetic field, and polarize and invert the neutrons entering the precession magnetic field. In some embodiments, the accelerator generates a target control signal for output to the signal generator 52, and controls the signal generator 52 to output a corresponding voltage to control the current amplifier 54 to output a corresponding current.
In the above embodiment, the mounting structure for fixing the guidance magnet 10 and the flip assembly is first constructed by the two support plates 30 and the four mounting brackets 40, then the guidance magnet 10 is mounted between the two support plates 30, and the flip assembly is mounted on the mounting brackets 40, at this time, the guidance magnet 10 generates the guidance magnetic field in the predetermined area. When the accelerator is emitting neutrons to the inversion assembly, a targeting control signal is generated and output to the drive device 50. The driving device 50 outputs corresponding currents to the first coil and the second coil, so that the first coil generates a compensation magnetic field opposite to the guiding magnetic field, and counteracts the compensation magnetic field to form a demagnetizing field area. And the second coil generates a precession magnetic field orthogonal to the guiding magnetic field and the compensation magnetic field in the demagnetizing field area, and then polarization reversal of neutrons is realized through Larmor precession of the neutrons. On the first hand, only the guiding magnet 10, the first coil and the second coil are needed to generate a guiding magnetic field, a compensation magnetic field and a precession magnetic field respectively, and then the polarization overturning of neutrons can be realized based on Larmor precession of the neutrons, so that the neutron polarization overturning device is simple in structure and convenient to realize. In the second aspect, the installation of the guidance magnet 10 and the flip assembly is achieved by two support plates 30 and four mounting brackets 40, which is simple to install and convenient to operate. In a third aspect, the driving device 50 outputs a corresponding current to enable the flipping module to generate a required magnetic field after receiving the accelerator targeting control signal, so as to implement the synchronous flipping of the neutrons along with the targeting control signal.
The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.
Claims (10)
1. A neutron polarization flipping device, comprising:
a guide magnet for generating a guide magnetic field in a preset region;
the overturning assembly comprises an overturning bracket, a first coil and a second coil, the first coil and the second coil are wound on the overturning bracket to be arranged in the preset area,
the driving device is used for outputting current to the first coil after receiving a target shooting control signal of the accelerator so as to generate a compensation magnetic field opposite to the guide magnetic field and enable the guide magnetic field and the compensation magnetic field to form a demagnetizing field area in an intersecting area, and is also used for outputting current to the second coil so as to enable the demagnetizing field area to generate a precession magnetic field orthogonal to the guide magnetic field and the compensation magnetic field, and the precession magnetic field is used for carrying out polarization overturning on neutrons entering the precession magnetic field.
2. A neutron polarization inverter, comprising:
a guide magnet for generating a guide magnetic field in a preset region;
the overturning assembly comprises an overturning bracket, a first coil and a second coil;
the first coil and the second coil are wound on the overturning support to be arranged in the preset area, the first coil is used for generating a compensation magnetic field opposite to the guide magnetic field after being electrified so that the guide magnetic field and the compensation magnetic field form a demagnetizing field area in an intersecting area, the second coil is used for generating a precession magnetic field orthogonal to the guide magnetic field and the compensation magnetic field in the demagnetizing field area after being electrified, and the precession magnetic field is used for polarizing and overturning neutrons entering the precession magnetic field.
3. The neutron polarization inverter of claim 1 or 2, wherein the steering magnets comprise a first set of magnets and a second set of magnets;
the first group of magnets and the second group of magnets are oppositely arranged on two sides of the preset area, and the first group of magnets and the second group of magnets are arranged in parallel, so that a guide magnetic field generated in the preset area between the first group of magnets and the second group of magnets is a uniform magnetic field.
4. The neutron polarization flipper of claim 3, wherein the guidance magnet further comprises a first set of magnet supports and a second set of magnet supports;
first group's magnet and second group magnet all include a plurality of magnet, first group magnet support and second group magnet support all seted up a plurality ofly with the mounting groove that magnet matches is a plurality of first group magnet support and second group magnet support's mounting groove is located respectively to magnet, in order to form respectively first group magnet with second group magnet.
5. The neutron polarization flipper of claim 3, wherein the flipper carriage includes two horizontal winding columns parallel to each other and two vertical winding columns perpendicular to the horizontal winding columns, respectively;
the first coil is wound on the two horizontal winding columns in a direction perpendicular to the horizontal winding columns, the second coil is wound on the two vertical winding columns in a direction perpendicular to the vertical winding columns, and the two vertical winding columns are respectively arranged in parallel with the first group of magnets and the second group of magnets.
6. The neutron polarization inverter of claim 5, wherein two horizontal winding columns or two vertical winding columns are extended to form a mounting block exposed out of the inversion bracket, and the mounting block is used for mounting and fixing the inversion bracket.
7. The neutron polarization inverter of claim 2, wherein the current output by the driving device received by the second coil during one polarization inversion of neutrons is varied to generate the precession magnetic field with a varying magnetic field strength, the rate of change of the magnetic field strength being less than a predetermined value.
8. The neutron polarization inverter of claim 7, wherein the magnetic field strength of the precession magnetic field varies from an initial magnetic field strength to a predetermined magnetic field strength, and from the predetermined magnetic field strength to the initial magnetic field strength.
9. The neutron polarization inverter of claim 2, wherein the second coil is configured to receive an electrical current output by a drive device when neutrons are emitted into the precessional magnetic field to generate the precessional magnetic field.
10. The neutron polarization flipper of claim 2, further comprising two support plates and four mounting brackets, wherein two of the mounting brackets have one end of one of the support plates sandwiched therebetween, wherein two of the mounting brackets have another end of the other support plate sandwiched therebetween, wherein two of the mounting brackets have one end of the other support plate sandwiched therebetween, wherein the guidance magnet is secured between the two support plates, and wherein the flipper bracket is secured to at least one of the mounting brackets.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211528470.6A CN115831432A (en) | 2022-11-30 | 2022-11-30 | Neutron polarization turning device and turner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211528470.6A CN115831432A (en) | 2022-11-30 | 2022-11-30 | Neutron polarization turning device and turner |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115831432A true CN115831432A (en) | 2023-03-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211528470.6A Pending CN115831432A (en) | 2022-11-30 | 2022-11-30 | Neutron polarization turning device and turner |
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| Country | Link |
|---|---|
| CN (1) | CN115831432A (en) |
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2022
- 2022-11-30 CN CN202211528470.6A patent/CN115831432A/en active Pending
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