CN207908664U - The antenna part of explosive and illicit drugs inspection system based on nuclear quadrupole resonance - Google Patents
The antenna part of explosive and illicit drugs inspection system based on nuclear quadrupole resonance Download PDFInfo
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- CN207908664U CN207908664U CN201720925084.9U CN201720925084U CN207908664U CN 207908664 U CN207908664 U CN 207908664U CN 201720925084 U CN201720925084 U CN 201720925084U CN 207908664 U CN207908664 U CN 207908664U
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Abstract
The utility model is related to the antenna parts of explosive and illicit drugs inspection system based on nuclear quadrupole resonance, including the transmitting antenna and reception antenna being looped around on detecting system channel, the transmitting antenna is mainly coaxial parallel and the transmitting coil of shapes is waited to form by two, which form helmholtz coils, magnetic field intensity in helmholtz coil is uniform, and the coaxial distance for forming two transmitting coils of helmholtz coil is determined by the size of transmitting coil；The transmitting antenna further includes at least one conductive coil, it is coaxial parallel respectively with described two transmitting coils and waits shapes, transmitting coil adjacent two-by-two or conductive coil is set to be respectively formed same helmholtz coil, to extend the length of uniform magnetic field in transmitting antenna；The reception antenna includes at least one receiving coil, between transmitting antenna.Its effect is while extending sense channel length, and to keep the magnetic field intensity in sense channel uniform, nuclear electric quadrupole technology is enable normally to detect explosive and drugs.
Description
Technical field
The utility model is related to explosives and illicit drugs inspection field, are based especially on the explosive and poison of nuclear quadrupole resonance
The antenna part of product examine examining system.
Background technology
Metal detection technology, terahertz detection technology, X-ray transmission-type detection technique, neutron detection technology wait traditional poison
Product explosives detection techniques, although to a certain extent it can be found that security risk, they are also deposited during application
In significant limitation.Metal detector can only detect the explosive with metal device, and usually to the gold of non-dangerous article
Belong to such as key, mobile phone, slide fastener generation wrong report；Terahertz detection technology imaging effect is poor, and technical difficulty is very big, and cost is very
It is high；X-ray transmission-type detection technique, can only distinguish organic matter, inorganic matter, metal；Neutron detection technology ionization radiation protection is difficult,
Protect cost very high.And these types of detection technique is all unable to the dangerous material such as qualitative detection drugs explosive, can not clearly know
Which kind of substance road detection is.And nuclear quadruple resonance detection technology is used, abbreviation NQR detection techniques not only can be to drugs
Explosive is detected, and can also avoid the deficiency of above-mentioned traditional drugs explosives detection techniques.
NQR detection techniques are to provide magnetic field to excite four polar cores in sample, after a certain period of time by a transmitting antenna
Exciting field is removed, the characteristic resonances signal of its generation is received using reception antenna.The magnetic field that transmitting antenna provides, it is necessary to be field
It is powerful, the high magnetic field of the uniformity, what such uniform magnetic field was typically built by a helmholtz coil, but He Muhuo
Hereby the same shaft size of coil is limited by coil size, and for luggage machine, helmholtz coil size is restricted,
Coil-span is also limited, then the space of its uniform magnetic field is also limited.And the narrow-band reception that our receiving coil uses,
When the space of uniform magnetic field is smaller, the layout of the narrow-band reception antenna of Multi-example detection will be closely and narrow
Band receiving coil at a distance of it is closer when, especially resonate frequency point it is not far from one another when, just have very serious mutual coupling.
In order to solve this problem, we just need to construct the uniform magnetic field in a bigger region.We are practical thus
A kind of novel structure similar with helmholtz coil carrys out the length of uniform magnetic field in extension coil.
Invention content
Technical problem to be solved by the utility model is to provide based on nuclear quadrupole resonance explosive and drugs inspection
The antenna part of examining system can extend the length of uniform magnetic field in transmitting antenna on its sense channel, avoid narrow-band reception antenna
Mutual coupling happen.
Technical solution used by the utility model is：Explosive and illicit drugs inspection system based on nuclear quadrupole resonance
Antenna part comprising the transmitting antenna and reception antenna being looped around on detecting system channel, the transmitting antenna mainly by
Two coaxial parallel and the transmitting coil of shapes is waited to form, and which form helmholtz coil, the magnetic field in helmholtz coil is strong
Degree is uniform, and the coaxial distance for forming two coils of helmholtz coil is determined by the size of coil；The transmitting antenna
Further include at least one conductive coil, it is coaxial parallel respectively with described two coils and wait shapes, make coil adjacent two-by-two or
Conductive coil is respectively formed same helmholtz coil, to extend the length of uniform magnetic field in transmitting antenna；
The reception antenna includes at least one receiving coil, between transmitting antenna.
Further, two hair line coils of the transmitting antenna and at least one conductive coil are cyclic structure, or
Person is polygonized structure.
Further, two transmitting coils of the transmitting antenna and at least one conductive coil structure are rectangle.
Further, two transmitting coils of the transmitting antenna and at least one conductive coil can be by a wires
Coiling forms, or is formed by several metal coilings.
Further, the transmitting antenna uses broadband emission；The reception antenna uses narrow-band reception.
Further, the receiving coil is 2 and 2 or more, is located at adjacent transmitting coil or conduction
The middle of coil.
Further, the transmitting coil and conductive pitch of the laps are formed by a hollow blister copper pipeline coiling.
The utility model makes to be formed using helmholtz coil using field homogeneity this advantage in helmholtz coil
Transmitting antenna in field homogeneity, nuclear quadrupole resonance technology detection explosive and drugs can be applied；Meanwhile Helmholtz
Coil is again because the coaxial distance of its own disadvantage-helmholtz coil is by forming the size institutes of two coils of helmholtz coil
It determines, in other words, transmitting antenna is looped around the distance on sense channel because the width of sense channel determines, thus to detection system
For system, detection zone may can only account for a sense channel part, and disadvantage has three：First point, because reception antenna narrowband connects
It receives, in the case that detection zone is narrow, when being detected to various samples, multiple receiving coils are laid out meeting closely,
Between adjacent receiving coil, very serious mutual coupling is will produce, severe jamming testing result, the frequency point that especially resonates is not at a distance of
When remote, mutual coupling situation is more very.Second point, in order to avoid or weaken coupling between multiple receiving coils, receiving coil it
Between to maintain a certain distance, caused by as a result, some receiving coil can be far from transmitting coil, when transmitting coil swashs
After sending out sample, sample and multiple receiving coils are all apart from each other, are generated during causing receiving coil that can not receive sample de excitation
Resonance signal；Two, in order to avoid or weaken coupling between multiple receiving coils, to be kept between receiving coil it is certain away from
From caused in this way as a result, some receiving coil can be far from transmitting coil, after transmitting coil excites sample, sample
Resonance signal all apart from each other with multiple receiving coils, being generated during causing receiving coil that can not receive sample de excitation；The
, sense channel can not be become to more complete detection zone at 3 points, detection range is limited.
As the above analysis, according to the length of sense channel width and sense channel, so as to adjust transmitting antenna
Conductive coil quantity extends the detection zone in detecting system its sense channel, results in the advantage that：First point, ensure whole
Field homogeneity in a detection zone applies the detection technique based on nuclear quadrupole resonance to meet；Second point will each receive line
Circle is located at the middle of adjacent transmission coil or conductive coil two-by-two, so that all coils is spaced out, avoids mutual coupling, examines
It is interference-free to survey result；Thirdly, when Multi-example detects, sample can be in equal near the receiving coil of each frequency point
In even magnetic field, the detection of the frequency point is received；4th point, sense channel is become into more complete detection zone, it is accurate to improve detection
Degree.
Description of the drawings
Fig. 1 is the structural schematic diagram of the utility model；
Fig. 2 is the transmitting antenna schematic diagram in Fig. 1；
Fig. 3 is the schematic diagram of the transmitting coil 1 and 2 of Fig. 2；
Fig. 4 is each point magnetic field intensity in the transmitting coil 1 of Fig. 3 and 2 sections with the coordinate diagram of its center o point distance changes；
Fig. 5 is the schematic diagram of the transmitting coil 1,2 and 3 of Fig. 1；
Fig. 6 is in the transmitting coil 1,2 and 3 of Fig. 5, and each point magnetic field intensity is with away from coil 1 and 2 central point O distance changes
Coordinate diagram；
Fig. 7 is the uniformity analogous diagram of internal magnetic field in Fig. 3；
Fig. 8 is the uniformity analogous diagram of internal magnetic field in Fig. 5；
Fig. 9 is the uniformity analogous diagram of internal magnetic field in Fig. 2.
Specific implementation mode
The utility model is described further below in conjunction with the accompanying drawings：
As shown in Figure 1, the antenna part of explosive and illicit drugs inspection system based on nuclear quadrupole resonance, including be looped around
Transmitting antenna and reception antenna on its sense channel of detecting system, transmitting antenna are mainly coaxial parallel and wait by least three
The transmitting coil 1,2,3,4 etc. of shape forms, and is formed by same wires coiling, also can by more wires coilings and
At according to helmholtz coil principle, adjacent transmitting coil 1 and 2,2 and 3,3 and 4 are respectively formed same He Muhuo two-by-two
Hereby coil group, due to the field homogeneity in every group of helmholtz coil, the magnetic field in that same helmholtz coil group is also all
It is uniform so that the magnetic field in transmitting antenna is all uniform（It is provable by being discussed below）.
Due to the same shaft size of every group of helmholtz coil be transmitted from coil dimension decision, so detecting system its
Under conditions of sense channel width is certain, the transmitting coil quantity of transmitting antenna, the ring for keeping transmitting antenna as wide as possible can be increased
It is wound on sense channel, the length of magnetic field of transmitting antenna is made to extend on sense channel as far as possible.
Reception antenna includes at least two receiving coils 22, is 3 receiving coils 22 shown in Fig. 1, only marks wherein one
22,3 receiving coils 22 of a receiving coil are located between transmitting coil 1 and 2,2 and 3,3 and 4, due to above-mentioned transmitting antenna
Topology layout extend the width on sense channel so that distance is pulled open between adjacent transmitting coil and receiving coil,
Avoid mutually leaning on is too close, generates coupling, influences the testing result using nuclear quadrupole resonance technology.
To reach preferable detection result, each receiving coil 22 be preferably located at transmitting antenna every adjacent transmission coil it
Between, and be middle position, when tested article being made to transport to any position with the conveyer belt of detecting system, removing transmitting coil
Magnetic field after, receiving coil can receive the nuclear quadrupole moment signal that tested article spontaneous radiation goes out.
In addition, transmitting antenna uses broadband emission, since nuclear quadrupole moment signal is very weak, if using broadband reception
Words, signal are often submerged in inside noise and cannot be found, so receiving coil can only use narrow-band reception, and nuclear quadrupole moment is total
Detection technique of shaking is four polar cores using magnetic excitation sample, is total to by what receiving coil reception sample spontaneous radiation went out
Shake signal, therefore can be to measured object qualitative detection.Multi-example is detected, different samples, nuclear quadrupolar resonance frequency
It differs, it is therefore necessary to be received using multiple narrowband coils.
Field homogeneity in transmitting antenna to prove the utility model formation, now passing through to calculate proves：
As shown in Fig. 2, 1,2,3,4 geometry of transmitting coil is identical, for rectangle and to be coaxially parallel to xoy flat
Face, and center is all in z-axis, since every adjacent windings of four transmitting coils form one group of helmholtz coil, i.e. emission lines
Circle 1,2 forms first group of helmholtz coil, i.e. transmitting coil 2, and 3 form second group of helmholtz coil, i.e. transmitting coil 3,4
Form third group helmholtz coil.Due to helmholtz coil principle, so the distance between four coils are identical.
As shown in figure 3, calculating in first group of helmholtz coil the magnetic field of any on Z axis
According to biot savart's law, the magnetic field of any on Z axis can be calculated
Therefore the field strength that each point in first group of Helmholtz section can be drawn becomes with transmitting coil 1 and 2 center O point distances
The coordinate diagram of change, such as Fig. 4.
Again as shown in figure 5, calculating influence of the coil 3 to first group of helmholtz coil internal magnetic field
According to the relational expression of Bz it is found that relationship between d and a, b,, and the magnetic induction that coil 3 generates is strong
Degree is with remoter apart from coil 3, and magnetic field intensity is smaller, and therefore, coil 3 distance, first group of helmholtz coil is remoter, to first
Field strength influence inside group helmholtz coil is just smaller, as shown in fig. 6, transmitting coil 3 is in first group of helmholtz coil
The coordinate diagram of portion magnetic field distance change.
It willAbove formula is substituted into, and in helmholtz coil,
Therefore it can derive
So
Therefore third coil influences the magnetic field intensity in first group of helmholtz coil very small, according to one third
Principle,It is i.e. negligible, thus the field strength in first group of helmholtz coil be still it is uniform, similarly, the influence of coil 1 and coil 4 to magnetic field in second group of helmholtz coil can also ignore, because
This coil 1 to the magnetic field between coil 4 be uniform.So the distance for lengthening uniform magnetic field in this way is feasible.
For our company such explosive and illicit drugs inspection product based on nuclear quadrupole resonance, the size of sense channel
It is 600（It is long）*500（It is wide）Mm, can calculate optimum distance 2a between the transmitting coil on this product sense channel=
300mm can calculate influence of the coil 3 to first group of helmholtz coil inside center point magnetic field, be。, say
Open-wire line circle 3 does not influence first group of helmholtz coil internal magnetic field.
Now the uniformity of transmitting antenna internal magnetic field is emulated, according to above-mentioned 2a=500mm, 2b=600mm, 2d=
300mm, r=5mm
For each group of helmholtz coil of transmitting antenna, the gradient in Z axis magnetic field is calculated as seen from Figure 7, Hz magnetic
Field intensity maximum value
Hmax=2.17*10^(-5)
Hmin =2.07*10^(-5)
Magnetic field homogeneity。
For first group of transmitting antenna and second group of helmholtz coil, calculating the gradient in Z axis magnetic field can be seen by Fig. 8
Go out, Hz maximum field strengths
Hmax=8.36*10^(-6),Hmin=5.77*10^(-6)
Magnetic field homogeneity。
First group, second group for transmitting antenna and third group helmholtz coil calculate the gradient in Z axis magnetic field by scheming
9 as can be seen that Hz maximum field strengths
Hmax =8.41*10^(-6)
Hmin=5.96*10^(-6)
Magnetic field homogeneity。
By above-mentioned emulation it is found that its internal magnetic field of transmitting antenna is uniform.
It is best for the antenna part of the explosive and illicit drugs inspection system based on nuclear quadrupole resonance of the utility model
Technical solution be that transmitting antenna is that hollow blister copper pipe is wound on the sense channel of detecting system, channel size 600
（It is long）*500（It is wide）mm.We use hollow blister copper pipe diameter 5mm, thickness 1mm, are because of the skin that becomes of conducting wire at high frequencies
Effect, when electric current flows through conductor, current density concentrates on conductive surface, and equivalent resistance increases.Hollow blister copper pipe increases conductor table
Area reduces equivalent resistance of the coil due to Kelvin effect at high frequencies, because being based on nuclear quadruple resonance detection system
Uniting, the excitation field strength needed is very big, and hollow copper tubing has relative area very big, and heat dissipation effect is good, overcomes due to accumulation of heat pair
The influence of ballistic device.And copper pipe is flexible, and ductility is good, is easily coiled into threadiness along sense channel, is easy sizing, and copper pipe
Intensity is high.The centre that hollow blister copper pipe is coiled into two neighboring circle is a receiving coil.Pass through calculation formula, because of 2a
=500mm, 2b=600, obtain the distance between two circles that hollow blister copper pipe is coiled into for 2d=Mm chooses hollow thick
Distance is 300mm between two circles that copper pipe is coiled into, big apart from heat dissipation area.
Correspondingly, hollow blister copper pipe can be coiled into two circles, three circles or all more multi-turn, receiving coil according to the length of sense channel
Positioned at the middle of two neighbours, two circle, for detecting tested product；No matter hollow blister copper pipe is around several circles, if receiving coil with it is hollow thick
Copper pipe does not couple.
Embodiment described above is only that preferred embodiments of the present invention are described, not to practical new
The range of type is defined, and under the premise of not departing from the spirit of the design of the utility model, those of ordinary skill in the art are to this reality
The various modifications made with novel technical solution and improvement should all fall into the protection model of the utility model claims book determination
In enclosing.
Claims (7)
1. the antenna part of explosive and illicit drugs inspection system based on nuclear quadrupole resonance comprising it is logical to be looped around detecting system
Transmitting antenna on road and reception antenna, the transmitting antenna is mainly by two transmitting winding groups that are coaxial parallel and waiting shapes
At which form helmholtz coil, the magnetic field intensity in helmholtz coil is uniform, and forms two of helmholtz coil
The coaxial distance of transmitting coil is determined by the size of transmitting coil；It is characterized in that：The transmitting antenna further includes at least one
A conductive coil, it is coaxial parallel respectively with described two transmitting coils and wait shapes, make transmitting coil adjacent two-by-two or conduction
Coil is respectively formed same helmholtz coil, to extend the length of uniform magnetic field in transmitting antenna；
The reception antenna includes at least one receiving coil, between transmitting antenna；
The center position of each two adjacent transmitting coil is arranged in parallel with 1 receiving coil.
2. the antenna part of explosive and illicit drugs inspection system according to claim 1 based on nuclear quadrupole resonance,
It is characterized in that：Two transmitting coils of the transmitting antenna and at least one conductive coil are cyclic structure, or are polygon
Shape structure.
3. the antenna part of explosive and illicit drugs inspection system according to claim 2 based on nuclear quadrupole resonance,
It is characterized in that：Two transmitting coils of the transmitting antenna and at least one conductive coil structure are rectangle.
4. the antenna part of explosive and illicit drugs inspection system according to claim 1 or 3 based on nuclear quadrupole resonance,
It is characterized in that：Two transmitting coils of the transmitting antenna and at least one conductive coil can by a wires coiling and
At, or formed by several metal coilings.
5. the antenna part of explosive and illicit drugs inspection system according to claim 4 based on nuclear quadrupole resonance,
It is characterized in that：The transmitting antenna uses broadband emission；The reception antenna uses narrow-band reception.
6. the antenna part of explosive and illicit drugs inspection system according to claim 5 based on nuclear quadrupole resonance,
It is characterized in that：The receiving coil is 2 and 2 or more, is being located at adjacent transmitting coil or conductive coil just
It is intermediate.
7. the antenna part of explosive and illicit drugs inspection system according to claim 6 based on nuclear quadrupole resonance,
It is characterized in that：The transmitting coil and conductive pitch of the laps are formed by a hollow blister copper pipeline coiling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720925084.9U CN207908664U (en) | 2017-07-27 | 2017-07-27 | The antenna part of explosive and illicit drugs inspection system based on nuclear quadrupole resonance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720925084.9U CN207908664U (en) | 2017-07-27 | 2017-07-27 | The antenna part of explosive and illicit drugs inspection system based on nuclear quadrupole resonance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207908664U true CN207908664U (en) | 2018-09-25 |
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ID=63570331
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| CN201720925084.9U Active CN207908664U (en) | 2017-07-27 | 2017-07-27 | The antenna part of explosive and illicit drugs inspection system based on nuclear quadrupole resonance |
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| CN (1) | CN207908664U (en) |
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- 2017-07-27 CN CN201720925084.9U patent/CN207908664U/en active Active
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