TW201824962A - A target and neutron capture treatment system that is used for neutron line to produce device - Google Patents

Abstract

The utility model provides a target and neutron capture treatment system that is used for neutron line to produce device can promote improvement neutron productivity and be used for the treatment in order to obtain sufficient neutron. The utility model discloses a neutron capture treatment system, including the neutron production device and the beam shaping body, the neutron produces the device and includes accelerator and target, and charged particle line and target effect that the accelerator produced with higher speed produce the neutron line, and the target includes active layer and base layer, and the active layer can produce with the effect of incident particle line neutron line, base layer can restrain the foaming that is aroused by the incident particle line can be supported again active layer, active layer include first active layer and second active layer, and the incident particle line passes first active layer and second active layer along the incident direction in proper order.

Description

   Target for neutron generating device and neutron capture treatment system   

One aspect of the present invention relates to a target used in a radiation irradiation system, and particularly to a target used in a particle radiation generating device; another aspect of the present invention relates to a radiation irradiation system, and more particularly, to a radiation irradiation system. Neutron Capture Therapy System.

With the development of atomic science, radiation therapy such as cobalt sixty, linear accelerator, electron beam has become one of the main means of cancer treatment. However, traditional photon or electron therapy is limited by the physical conditions of the radiation itself. While killing tumor cells, it will also cause damage to a large number of normal tissues in the beam path. In addition, due to the different sensitivity of tumor cells to radiation, traditional radiation therapy Treatment of radiation-resistant malignancies (eg, glioblastoma multiforme, melanoma) is often not effective.

In order to reduce radiation damage to normal tissues surrounding tumors, the concept of target therapy in chemotherapy has been applied to radiation therapy. At the same time, tumor cells with high radiation resistance have also been actively developed with high relative biological effects. biological effectiveness (RBE) radiation sources, such as proton therapy, heavy particle therapy, neutron capture therapy, etc. Among them, neutron capture therapy is a combination of the above two concepts, such as boron neutron capture therapy, which uses boron-containing drugs to specifically accumulate in tumor cells and cooperates with precise neutron beam regulation to provide better than traditional radiation. Cancer treatment options.

In the accelerator boron neutron capture therapy, the accelerator boron neutron capture therapy accelerates the proton beam through the accelerator, which accelerates the proton beam to an energy sufficient to overcome the Coulomb repulsive force of the target atomic nucleus to generate a neutron with the target to generate neutrons. Productivity to obtain sufficient neutrons for treatment is a core issue in system design.

Therefore, it is necessary to propose a new technical solution to solve the above problems.

In order to solve the above problems, one aspect of the present invention is to provide a target for a neutron generating device, which includes an active layer and a base layer, and the active layer can interact with the incident particle line to generate a neutron line. The suppression of the foam caused by the incident particle line can also support the action layer. The action layer includes a first action layer and a second action layer, and the incident particle line passes through the first action layer and the second action layer in order along the incident direction. The use of the first active layer and the second active layer provided along the incident direction of the particle line can increase the neutron yield.

The materials of the first and second active layers are all materials capable of undergoing a nuclear reaction with the incident particle rays, and the materials of the first and second active layers are different.

The material of the first active layer is Be or its alloy, the material of the second active layer is Li or its alloy, the incident particle line is a proton line, and the first and second active layers generate ⁹ Be (p, n) with the proton line, respectively. ⁹ B and ⁷ Li (p, n) ⁷ Be nuclear reactions to generate neutrons, the energy of the protons is 2.5MeV-5MeV, and the neutron yield is 7.31E-05 n / proton-5.61E-04 n / proton. Using Be or its alloy as the first active layer can prevent the first and second active layers from being oxidized, is not easy to be corroded by the second active layer, and can reduce the loss of incident proton beams and the heat generated by the proton beams. A nuclear reaction occurs, further increasing the neutron yield.

The thickness of the first active layer is 5 μm -25 μm , and the thickness of the second active layer is 80 μm -240 μm .

The second active layer is connected to the base layer through a casting, evaporation or sputtering process, and the first active layer closes the base layer to form a cavity and / or surrounds the second active layer through a HIP process.

An adhesion layer is provided between the second active layer and the base layer, and the material of the adhesion layer includes at least one of Cu, Al, Mg, or Zn.

The target material for the neutron generating device of the present invention further includes a heat dissipation layer including a cooling channel, and the cooling channel is formed by additive manufacturing. The heat dissipation layer has cooling channels, which improves the heat dissipation effect and helps to extend the life of the target.

The base layer is made of a material that suppresses foaming, the heat dissipation layer is made of a thermally conductive material or a material that can both conduct heat and foam, and a material that suppresses foaming or a material that can both conduct heat and foam includes Fe, At least one of Ta or V, the thermally conductive material includes at least one of Cu, Fe, and Al, and the heat dissipation layer and the base layer are connected by a HIP process.

The heat dissipation layer and the base layer are at least partially made of the same material or integrated, and the same material is Ta or Ta-W alloy.

Another aspect of the present invention provides a neutron capture therapy system, which includes a neutron generating device and a beam shaper. The neutron generating device includes an accelerator and a target. The charged particle beam generated by the accelerator accelerates to generate a neutron by interacting with the target. The beam shaping body includes a reflector, a retarder, a thermal neutron absorber, a radiation shield, and a beam exit. The retarder reduces the neutrons generated from the target material to the superheated neutron energy region, and the reflector surrounds the retarder. The neutron is deflected and the deviated neutron is returned to the retarder to increase the intensity of the superheated neutron beam. The thermal neutron absorber is used to absorb thermal neutrons to avoid excessive doses with shallow normal tissue during treatment. The beam exit is arranged at the rear of the reflector for shielding leaked neutrons and photons to reduce the normal tissue dose in the non-irradiated area. The target is as described above.

In the target of the embodiment of the present invention, the active layer includes a first active layer and a second active layer, and an incident particle line passes through the first active layer and the second active layer in order along the incident direction. The use of the first active layer and the second active layer provided along the incident direction of the particle line can increase the neutron yield.

100‧‧‧ Boron Neutron Capture Therapy Device

10‧‧‧ Neutron Generator

11‧‧‧ accelerator

111‧‧‧Accelerator

12‧‧‧ heat dissipation layer

121‧‧‧Tube

122‧‧‧Support

1221‧‧‧First support

1222‧‧‧Second support

1223‧‧‧third support

123‧‧‧ protrusion

124‧‧‧Second Wall

13‧‧‧ base layer

14‧‧‧action layer

15‧‧‧anti-oxidation layer

16‧‧‧ Adhesive layer

17‧‧‧ Connection Department

20‧‧‧ Beam Shaping Body

21‧‧‧Reflector

22‧‧‧ Slow body

23‧‧‧ thermal neutron absorber

24‧‧‧ Radiation Shield

25‧‧‧ Beam exit

30‧‧‧ Collimator

40‧‧‧Treatment Table

50‧‧‧ radiation shielding device

51‧‧‧ medical image scanning device

52‧‧‧Data processing and 3D modeling device

53‧‧‧shield

531‧‧‧ center through hole

200‧‧‧patients

T‧‧‧Target

C‧‧‧ Charged Particle Line

N‧‧‧neutron

M‧‧‧ tumor cells

P‧‧‧ cooling channel

P1‧‧‧first cooling channel

P2‧‧‧Second cooling channel

P3‧‧‧third cooling channel

IN‧‧‧Cooling inlet

OUT‧‧‧cooling outlet

D1‧‧‧The first cooling pipe

D2‧‧‧Second cooling pipe

S‧‧‧ cooling surface

W‧‧‧Inner wall

D‧‧‧Cooling medium circulation direction

P ', P "‧‧‧ subchannel

FIG. 1 is a schematic diagram of a neutron capture therapy system in an embodiment of the present invention.

FIG. 2 is a schematic diagram of a target in an embodiment of the present invention.

FIG. 3 is a partially enlarged schematic view of the target in FIG. 2.

FIG. 4 is a schematic view of the heat dissipation layer of the target in FIG. 2 viewed from the direction A. FIG.

FIG. 5 a is a schematic diagram of a first embodiment of an inner wall of a heat dissipation channel of the target in FIG. 2.

Fig. 5b is a schematic view along the axis B-B of the first embodiment of the inner wall of the heat dissipation channel of the target in Fig. 2.

FIG. 6 a is a schematic diagram of a second embodiment of the inner wall of the heat dissipation channel of the target in FIG. 2.

Fig. 6b is a schematic view along the axis C-C of the second embodiment of the inner wall of the heat dissipation channel of the target in Fig. 2.

FIG. 7 is a schematic diagram of a third embodiment of the inner wall of the heat dissipation channel of the target in FIG. 2.

The embodiments of the present invention are further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement the present invention with reference to the description text.

As shown in FIG. 1, the neutron capture treatment system in this embodiment is preferably a boron neutron capture treatment system 100, which includes a neutron generation device 10, a beam shaper 20, a collimator 30, and a treatment table 40. The neutron generating device 10 includes an accelerator 11 and a target T. The accelerator 11 accelerates charged particles (such as protons, deuterons, etc.) to generate charged particle lines C such as proton lines. The charged particle lines C are irradiated to the target T and interact with the target T. The target T generates a neutron (neutron beam) N, and the target T is preferably a metal target. Select the appropriate nuclear reaction based on the required neutron yield and energy, the energy and current available for the accelerated charged particles, and the physical and chemical properties of the metal target. The nuclear reactions that are often discussed are ⁷ Li (p, n) ⁷ Be and ⁹ Be (p, n) ⁹ B, these two reactions are endothermic reactions. The energy thresholds of the two nuclear reactions are 1.881 MeV and 2.055 MeV, respectively. Since the ideal neutron source for boron neutron capture therapy is super thermal neutrons of keV energy level, theoretically, if a proton with an energy slightly higher than the threshold is used to bombard a lithium metal target Materials, which can generate relatively low-energy neutrons, can be used in the clinic without too much slow-speed treatment. However, the lithium metal (Li) and beryllium metal (Be) targets and threshold energy proton interaction cross sections are not high. To generate a sufficiently large neutron flux, higher energy protons are usually used to initiate the nuclear reaction. The ideal target should have high neutron yield, neutron energy distribution close to the superthermal neutron energy region (described in detail below), no too much strong penetrating radiation, safe and cheap, easy to operate, and high temperature resistance. It is not actually possible to find a nuclear reaction that meets all requirements. As is well known to those skilled in the art, the target T may also be made of a metal material other than Li and Be, for example, Ta or W and an alloy thereof. The accelerator 11 may be a linear accelerator, a cyclotron, a synchrotron, or a synchrocyclotron.

The neutron beam N generated by the neutron generator 10 is irradiated to the patient 200 on the treatment table 40 through the beam shaper 20 and the collimator 30 in this order. The beam shaper 20 can adjust the beam quality of the neutron beam N generated by the neutron generating device 10, and the collimator 30 is used to converge the neutron beam N, so that the neutron beam N has a higher quality during the treatment process. Targeting. The beam shaping body 20 further includes a reflector 21, a retarder 22, a thermal neutron absorber 23, a radiation shield 24, and a beam exit 25. The neutrons generated by the neutron generator 10 have a wide energy spectrum, except for superheated In addition to neutrons meeting treatment needs, other types of neutrons and photons need to be reduced as much as possible to avoid harm to the operator or the patient. Therefore, the neutrons from the neutron generating device 10 need to pass the retarder 22 to quickly neutralize them. The neutron energy is adjusted to the superthermal neutron energy region. The retarder 22 is made of a material having a large cross-section with fast neutrons and a small cross-section with superthermal neutrons. In this embodiment, the retarder 22 is made of D ₂ O, AlF ₃ , Fluental, CaF ₂ , Li ₂ CO ₃ , MgF ₂ and Al ₂ O ₃ ; the reflector 21 surrounds the retarder 22 and reflects back the neutrons diffused through the retarder 22 to the surroundings The neutron beam N is used to improve the utilization rate of neutrons. It is made of a material with strong neutron reflection ability. In this embodiment, the reflector 21 is made of at least one of Pb or Ni; A thermal neutron absorber 23 made of a material with a large cross section acting on the thermal neutron In this embodiment, the thermal neutron absorber 23 is made of Li-6. The thermal neutron absorber 23 is used to absorb the thermal neutrons passing through the retarder 22 to reduce the content of thermal neutrons in the neutron beam N and avoid treatment. Excessive dose is caused by shallow and normal tissues; the radiation shield 24 is arranged around the beam exit 25 at the rear of the reflector to shield neutrons and photons leaking from the part outside the beam exit 25. The material of the radiation shield 24 includes At least one of a photon shielding material and a neutron shielding material. In this embodiment, the material of the radiation shielding body 24 includes a photon shielding material lead (Pb) and a neutron shielding material polyethylene (PE). It can be understood that the beam shaper 20 may have other structures as long as the superheated neutron beam required for treatment can be obtained. The collimator 30 is arranged at the rear of the beam exit 25. The superheated neutron beam coming out of the collimator 30 is irradiated to the patient 200. After passing through the shallow normal tissue, it is slowed down to reach the tumor cell M by thermal neutrons. It can be understood that the collimator The device 30 can also be eliminated or replaced by other structures, and the neutron beam exits the beam exit 25 and directly irradiates the patient 200. In this embodiment, a radiation shielding device 50 is further provided between the patient 200 and the beam exit 25 to shield the radiation from the beam exiting the beam exit 25 to the normal tissue of the patient. It is understood that the radiation shielding device 50 may not be provided. .

After taking or injecting a boron-containing (B-10) drug to patient 200, the boron-containing drug selectively accumulates in tumor cells M, and then the boron-containing (B-10) drug has a characteristic of high capture cross-section for thermal neutrons. ^{The 10} B (n, α) ⁷ Li neutron capture and nuclear fission reactions produce two heavily charged particles, ⁴ He and ⁷ Li. The average energy of two charged particles is about 2.33MeV, having a high linear transfer (Linear Energy Transfer, LET), short-range features, linear energy α shorter particle transfer and range were 150keV / μm, 8μm, and ⁷ Li heavy charged particles is 175keV / μm, 5μm, the total range of the two particles is about the size of a cell, so the radiation damage to the organism can be limited to the cell level, and it can achieve local killing without causing too much damage to normal tissues. Purpose of dead tumor cells.

The structure of the target T will be described in detail below with reference to FIGS. 2, 3 and 4.

The target T is disposed between the accelerator 11 and the beam shaping body 20. The accelerator 11 has an acceleration tube 111 that accelerates the charged particle line C. In this embodiment, the acceleration tube 111 extends the incident beam shaping along the direction of the charged particle line C. The body 20 passes through the reflector 21 and the retarder 22 in this order. The target T is disposed in the retarder 22 and located at the end of the acceleration tube 111 to obtain better neutron beam quality.

The target T includes a heat dissipation layer 12, a base layer 13, and an active layer 14. The active layer 14 interacts with the charged particle line C to generate neutrons, and the base layer 13 supports the active layer 14. In this embodiment, the material of the active layer 14 is Li or an alloy thereof, the charged particle line C is a proton line, and the target T further includes an anti-oxidation layer 15 on the side of the active layer 14 for preventing the active layer from oxidizing, and a base layer. 13 can simultaneously suppress foaming caused by incident proton lines, and the charged particle line C sequentially passes through the anti-oxidation layer 15, the active layer 14, and the base layer 13 along the incident direction. The material of the anti-oxidation layer 15 also considers that it is not easy to be corroded by the active layer and can reduce the loss of the incident proton beam and the heat generated by the proton beam, such as at least one of Al, Ti and its alloy, or stainless steel. In this embodiment, the anti-oxidation layer 15 is a material capable of undergoing a nuclear reaction with protons at the same time, which can further increase the neutron yield while performing the above functions. At this time, the anti-oxidation layer is also a part of the active layer. Or its alloy, the energy of the incident proton beam is higher than the energy threshold of the nuclear reaction with Li and Be, which respectively produce two different nuclear reactions, ⁷ Li (p, n) ⁷ Be and ⁹ Be (p, n) ⁹ B; Be has a high melting point and good thermal conductivity. Its melting point is 1287 ° C and its thermal conductivity is 201W / (m K). Compared to Li (melting point is 181 ° C, its thermal conductivity is 71W / (m K)), The heat dissipation performance has great advantages, which further increases the life of the target, and the reaction threshold of the (p, n) nuclear reaction with protons is about 2.055 MeV. Most accelerator neutron sources using proton beams have higher energy than this. Reaction threshold, and the beryllium target is the best choice other than the lithium target. Compared with the anti-oxidation layer using other materials, such as Al, the neutron yield is improved due to the presence of Be. In this embodiment, the proton energy is 2.5MeV-5MeV, which can generate a higher active cross section with the lithium target, while not generating too many fast neutrons, and obtaining better beam quality; the thickness of the active layer 14 is 80 μ m-240 μ m, can fully react with protons, and will not be too thick to cause energy deposition and affect the heat dissipation performance of the target; while achieving the above-mentioned effects, while ensuring lower manufacturing costs, the thickness of the anti-oxidation layer 15 is 5 μm -25 μm . In the comparative test, Monte Carlo software was used to simulate 2.5MeV, 3MeV, 3.5MeV, 4MeV, 4.5MeV, and 5MeV proton beams, which were sequentially injected into the anti-oxidation layer 15 from the direction perpendicular to the active surface of the target T. Layer 14 (Li) and base layer 13 (Ta, which will be described in detail later), the material of the anti-oxidation layer 15 is compared with Al and Be, and the thickness of the anti-oxidation layer 15 is 5 μm , 10 μm , 15 μm , 20 μm , 25 μm , the thickness of the active layer 14 is 80 μm , 120 μm , 160 μm , 200 μm , 240 μm , and the thickness of the base layer 12 has almost no effect on the neutron yield It can be adjusted according to actual conditions, and the results of the neutron yield (ie, the number of neutrons produced by each proton) are shown in Tables 1 and 2. The calculation results of the neutron yield improvement ratio of the anti-oxidation layer relative to Al using Be as the lithium target are shown in Table 3. From the results, it is known that when Be is used as the anti-oxidation layer material, the neutron yield is significantly improved relative to Al. The neutron yield that can be obtained is 7.31E-05 n / proton-5.61E-04 n / proton.

The heat dissipation layer 12 is made of a thermally conductive material (such as Cu, Fe, Al and other materials with good thermal conductivity) or a material that can conduct heat and suppress foaming; the base layer 13 is made of a foam suppressing material; foam suppressing The material or material that can both conduct heat and suppress foaming includes at least one of Fe, Ta or V. The heat dissipation layer can have various structures, such as a flat plate. In this embodiment, the heat dissipation layer 12 includes a tubular member 121 and a support member 122. The material of the tubular member 121 and the support member 122 is Cu, which has good heat dissipation performance and cost. Lower, the tubular member 121 is composed of multiple tubes side by side and is positioned and installed by the support member 122. The support member 122 is fixed to the retarder 22 or the end of the acceleration tube 111 by connecting members such as bolts or screws. It can be understood that Use other detachable connections for easy target replacement. The structure of the tube increases the heat dissipation area, improves the heat dissipation effect, and helps extend the life of the target. The heat radiating layer 12 also has a cooling channel P through which a cooling medium flows. In this embodiment, the cooling medium is water, and the cooling channel P is formed at least partially inside the tube constituting the tubular member 121. The cooling medium flows through the inside of the tube to take away its heat. The inside acts as a cooling channel, which further enhances the heat dissipation effect and extends the target life. The shape, number and size of the tubes are determined according to the size of the actual target. In the figure, only four circular tubes are schematically drawn. It can be understood that they can also be square tubes, polygonal tubes, oval tubes, etc. and their combinations; Adjacent tubes can be close to each other so that their outer surfaces are in contact with each other, or they can be spaced apart. The cross-sectional shape of the inner hole of the tube can also be various, such as circular, polygonal, oval, etc. Different cross sections are also Can have different shapes. Because the diameter of each tube in the actual manufacturing of the tubular member is small, and there are cooling channels inside, the conventional production process is difficult. In this embodiment, additive manufacturing is used to obtain the tubular member, which facilitates the molding of microstructures and complex structures. . First, three-dimensional modeling of the tubular part, registration of the three-dimensional model data of the tubular part into the computer system, and layering into two-dimensional slice data, and the raw materials (such as copper powder) are manufactured layer by layer through a computer-controlled additive manufacturing system. , And finally obtain a three-dimensional product after superimposing.

When the base layer 13 is made of Ta, it has a certain heat dissipation effect and can reduce foaming, inhibit the inelastic scattering of protons and Li to release γ, and prevent excess protons from passing through the target; in this embodiment, the base layer The material of 13 is a Ta-W alloy, which can obviously improve the disadvantages of low strength and poor thermal conductivity of pure tantalum while maintaining the excellent properties of Ta, so that the heat generated by the nuclear reaction of the active layer 14 can be conducted away from the base layer in time. At this time, the heat dissipation layer may also be made of the same material or integrated structure as the base layer at least in part. The weight percentage of W in the Ta-W alloy is 2.5% -20% to ensure that the base layer suppresses foaming characteristics, and at the same time, the base layer has higher strength and thermal conductivity, which further extends the target service life. Ta-W alloys (such as Ta-2.5wt% W, Ta-5.0wt% W, Ta-7.5wt% W, Ta-10wt% W, Ta-12wt% w, Ta- 20wt% W, etc.) to make a plate-like base layer 13 with a proton energy of 1.881 MeV-10 MeV and a thickness of the base layer of at least 50 μm to fully absorb excess protons.

In this embodiment, the manufacturing process of the target T is as follows: S1: The liquid lithium metal is poured onto the base layer 13 to form an active layer 14, which can also be treated by evaporation or sputtering, and it can also be between lithium and tantalum. An extremely thin adhesion layer 16 is provided. The material of the adhesion layer 16 includes at least one of Cu, Al, Mg, or Zn, and can also be treated by evaporation or sputtering to improve the adhesion between the base layer and the active layer; S2: The HIP (Hot Isostatic Pressing) process is performed on the tubular member 121 of the base layer 13 and the heat dissipation layer 12; S3: The anti-oxidation layer 15 is simultaneously HIP processed or the base layer 13 is closed by other processes to form a container. The cavity and / or the active layer 14 is surrounded; S4: the support member 122 and the tubular member 121 are connected by welding, press fitting, or the like.

The above steps S1, S2, S3, and S4 are in no particular order. For example, the anti-oxidation layer 15 and the base layer 13 may be subjected to HIP treatment or the base layer 13 may be closed to form a cavity by other processes, and then the liquid lithium metal An active layer 14 is formed by pouring into the cavity. It can be understood that the supporting member 122 may also be omitted, and a plurality of tubes may be connected and fixed in sequence by welding or other methods. The base layer 13, the active layer 14, and the anti-oxidation layer 15 on each tube are respectively formed, and the tubular member and the support member 122 are positioned and connected. After the connection, the base layer 13, the active layer 14, and the anti-oxidation formed on each tube are formed. The entirety of layer 15 may be discontinuous, so it is necessary to form a connecting portion 17 between adjacent tubes. The connecting portion 17 is also composed of a base layer 13, an active layer 14, and an antioxidant layer 15. The entire target is divided into Multiple separate active parts further reduce the blistering phenomenon of the metal anti-oxidation layer. At this time, the connection between the support member 122 and the tubular member 121 in S4 can also be detachable, so the target T can be partially replaced. Prolong the service life of the target and reduce the cost of patient treatment; it can be understood that the base layer 13, the active layer 14, and the anti-oxidation layer 15 on each tube can also be integrally formed and then connected to the tubular member, so that the active layer of the target T after connection The whole is continuous, which is beneficial for the action of the charged particle beam C and the target T. At this time, the support member 122 and the tubular member 121 can also be obtained by additive manufacturing, reducing the difficulty of processing and assembly. The shape of the entirety of the base layer 13, the active layer 14, and the anti-oxidation layer 15 in a cross section perpendicular to the center line of the tube may also be various, such as connecting the base layer 13, the active layer 14, and the anti-oxidation layer 15 to a tubular member. The contours of the outer surface on one side are the same. In this embodiment, the outer arc shape increases the area where the target T interacts with the charged particle line C and the area where the heat dissipation layer 12 contacts the base layer 13 and conducts heat; each tube The upper active layer 14 covers at least 1/4 of the outer circumference of the tube, that is, the angle α between the active layer and the center line of the tube is at least 45 degrees.

In this embodiment, the support member 122 includes a first support portion 1221 and a second support portion 1222, which are symmetrically disposed at both ends of the tubular member 121 and have a cooling inlet IN and a cooling outlet OUT, respectively. The cooling channel P communicates with the cooling inlet IN and the cooling. Exit OUT. The cooling channel P includes a first cooling channel P1 on the first support portion, a second cooling channel P2 on the second support portion, and a third cooling channel P3 formed inside a tube constituting the tubular member 121. The cooling medium enters from the cooling inlet IN on the first support portion 1221, and simultaneously enters each of the tubes constituting the tubular member 121 through the first cooling channel P1, and then exits from the cooling outlet OUT through the second cooling channel P2 on the second support portion. . The target T is heated by the high-temperature accelerated proton beam irradiation temperature, and the base layer and the heat dissipation layer radiate heat, and the heat is taken out by the cooling medium circulating in the tubular member and the support member, so that the target material is heated. T is cooled.

It can be understood that the first cooling channel P1 and the second cooling channel P2 can also adopt other settings, such as the cooling medium entering from the cooling inlet IN on the first support portion 1221 passes through the interior of each tube constituting the tubular member 121 in sequence, and finally It comes out from the cooling outlet OUT on the second supporting part; the cooling medium can also directly enter and exit the tubular member without passing through the supporting member. At this time, the cooling inlet IN and the cooling outlet OUT can be arranged on the tubular member 121, and the tubes are connected in sequence. Forming a cooling channel P, the cooling medium flows through the interior of each tube in turn.

The support member 122 may further include a third support portion 1223 connecting the first and second support portions 1221 and 1222. The third support portion 1223 is in contact with the other side of the tubular member 121 on the side opposite to the connection layer 14, and the third support The portion 1223 may also have a fourth cooling channel constituting the cooling channel P. At this time, the cooling medium may pass only through the support member 122 without passing through the interior of each tube of the tubular member 121. The cooling channels in the support member 122 can be arranged in various ways, such as spiral to pass as much as possible through the area in contact with the tube; the cooling medium can also pass through the tube and the third support portion of the support member or both The first, second, and third support portions that pass through the interior of the tube and then through the support.

In this embodiment, first and second cooling pipes D1 and D2 are disposed between the acceleration tube 111 and the reflector 21 and the retarder 22, and one end of the first and second cooling pipes D1 and D2 is respectively connected to the cooling inlet of the target T. IN and cooling outlet OUT are connected, and the other end is connected to an external cooling source. It can be understood that the first and second cooling pipes can also be arranged in the beam shaping body in other ways. When the target is placed outside the beam shaping body, it can also be cancelled.

With continued reference to FIGS. 5-7, one or more protrusions 123 having a cooling surface S may be provided in the cooling channel P to increase the heat dissipation surface and / or form eddy currents to enhance the heat dissipation effect. The cooling surface S is a cooling medium in The surface that can contact the protruding portion 123 during the circulation in the cooling channel P. The protruding portion 123 protrudes from the inner wall W of the cooling channel P in a direction perpendicular or inclined to the cooling medium flow direction D. It can be understood that the protruding portion 123 can also be in other forms. It protrudes from the inner wall W of the cooling passage P. In the direction perpendicular to the cooling medium flow direction D, the maximum distance L1 of the protruding portion 123 extending from the inner wall W of the cooling channel P is less than half of the distance L2 extending in the extending direction to the opposite inner wall W. The protruding portion 123 cannot affect The free circulation of the cooling medium in the cooling channel P, that is to say, the protrusion cannot function to divide a cooling channel into several basically independent cooling channels (the cooling medium does not affect each other).

In the first embodiment of the cooling channel shown in FIGS. 5a and 5b, the protruding portion 123 protrudes from the inner wall W of the cooling channel P in a direction perpendicular to the cooling medium flow direction D, and the inner wall W of the cooling channel P is a cylindrical surface. The protruding portion 123 is a bar extending linearly along the cooling medium flow direction D. It can be understood that the inner wall W of the cooling channel P may have other shapes, and the protruding portion 123 may also have a spiral shape or other shape from the cooling channel P. The inner wall W extends along the cooling medium flow direction. In the figure, there are 10 protrusions and they are evenly distributed along the inner wall W. It can be understood that the protrusions can also be other numbers or only provided on the inner wall W of the cooling channel that is in contact with the active layer or the base layer. Adjacent protrusions may also have different shapes and / or protrusion lengths. The cross-sectional shape of the protrusion 123 in a direction perpendicular to the cooling medium flow direction D may be rectangular, trapezoidal, triangular, and the like; different cross-sectional shapes or sizes may also be different, such as pulsating, zigzag, or wavy in the cooling medium flow direction. Sub-protrusions 1231 are provided on the cooling surface S of the protrusions 123. In this embodiment, the cross-sectional shape of the sub-protrusions 1231 perpendicular to the cooling medium flow direction D is zigzag and extends along the cooling medium flow direction D. It can be understood The sub-protrusions can also have various structures as long as they can increase the heat dissipation surface. In this embodiment, the sub-protrusions 1231 are only schematically provided on one of the cooling surfaces of the protrusions 123. It can be understood that the sub-protrusions The portion 1231 may also be provided on any other cooling surface of the protruding portion 123.

Figures 6a and 6b show a second embodiment of the cooling channel. Only the differences from the first embodiment are described below. The protrusions 123 are rings distributed at intervals in the cooling medium flow direction. It can be understood that the rings can also be ring-shaped. At least a part. The number of rings and the length of the cooling channel in the figure are only for illustration, and can be adjusted according to the actual situation. In this embodiment, the end surface of the ring is a plane perpendicular to the cooling medium flow direction D, and it can be understood that it may also be a plane inclined to the cooling medium flow direction D or a tapered surface or curved surface.

Referring to FIG. 7, in a third embodiment of the cooling channel, at least one second wall 124 is provided in the cooling channel P to divide the cooling channel P into at least two independent sub-channels P ′ and P ″, and at least two adjacent sub-channels. The cooling medium flows in different directions in the channel, which increases heat dissipation efficiency. In this embodiment, the second wall 124 is cylindrical and passes through each of the protrusions 123 on the basis of the first embodiment, inside the cylindrical second wall 124 A sub-channel P 'is formed, and at the same time, a sub-channel P "is formed between every 2 adjacent protrusions 123 and the second wall 124, thereby forming 10 sub-channels P" around the sub-channel P', and at least The flow direction of the cooling medium in one sub-channel P "is different, and the flow direction of the cooling medium in at least two adjacent sub-channels P" may also be different. It can be understood that the second wall may have other Setting method: The protrusions in the cooling channel and the sub-protrusions on it further increase the manufacturing difficulty, therefore, the protrusions and / or the second wall can be formed separately and then inserted into the tube for positioning, or integrated with the tube through the additive Manufacturing obtained.

It can be understood that the heat dissipation layer 12 can also be used as the base layer 13 at this time. At this time, the heat dissipation layer 12 is at least partially made of a material that can conduct heat and suppress foaming, such as a tube made of Ta or Ta-W alloy. The support 121 is made of the piece 121 and Cu, and the active layer 14 is connected to the Ta or Ta-W alloy tube through a process such as evaporation or sputtering. The Ta or Ta-W alloy tube serves as the base layer 12 and the heat dissipation layer 13 at the same time. In this embodiment, the target T has a rectangular plate shape as a whole; it can be understood that the target T may also have a circular plate shape, and the first support portion and the second support portion constitute the entire circumference or a part of the circumference. At this time, the length of the tube may be Different; the target T can also be other solid shapes; the target T can also be movable relative to the accelerator or the beam shaper, in order to facilitate the change of the target or make the particle line and the target uniform. The active layer 14 may be a liquid (liquid metal).

It can be understood that the target of the present invention can also be applied to other neutron generating devices in the medical and non-medical fields. As long as the generation of neutrons is based on the nuclear reaction between the particle line and the target, the target material is also based on different nuclear reactions. Difference; it can also be applied to other particle beam generating devices.

The "tubular member" in the present invention refers to a whole formed by arranging a plurality of individual tubes and connecting them through a connecting member or a connecting process, and forming a hollow portion with one or more plate-shaped members or combining them to form a hollow portion. An object cannot be understood as a tubular piece of the invention.

Although the illustrative specific embodiments of the present invention have been described above so that those skilled in the art can understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments, and for those of ordinary skill in the art, As long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious and all fall within the scope of protection of the present invention.

Claims (10)

    A target for a neutron line generating device includes an action layer and a base layer, and the action layer can interact with incident particle lines to generate the neutron line. The base layer can both suppress the development of the particles caused by the incident particle lines. The bubble can support the active layer. The active layer includes a first active layer and a second active layer, and the incident particle line passes through the first active layer and the second active layer in order along the incident direction.         The target material for a neutron generating device as described in the first patent application range, wherein the materials of the first and second active layers are all materials capable of nuclear reaction with the incident particle line. The material of the second active layer is different.     The target for a neutron generating device according to item 2 of the scope of the patent application, wherein the material of the first active layer is Be or an alloy thereof, and the material of the second active layer is Li or an alloy thereof. The incident particle line is a proton line, and the first and second active layers respectively undergo ⁹ Be (p, n) ⁹ B and ⁷ Li (p, n) ⁷ Be nuclear reactions with the proton line to generate neutrons. The energy is 2.5MeV-5MeV, and the neutron yield is 7.31E-05 n / proton-5.61E-04 n / proton. The target for a neutron generating device according to item 1 of the patent application scope, wherein the thickness of the first active layer is 5 μm -25 μm , and the thickness of the second active layer is 80 μm -240 μm .     The target for a neutron generating device according to item 1 of the patent application scope, wherein the second active layer is connected to the base layer through a casting, evaporation or sputtering process, and the first active layer is connected through HIP. The process closes the base layer to form a cavity and / or surrounds the second active layer.         The target for a neutron generating device according to item 1 of the scope of patent application, wherein an adhesion layer is provided between the second active layer and the base layer, and the material of the adhesion layer includes Cu, Al, Mg or At least one of Zn.         The target material for a neutron generating device according to item 1 of the scope of the patent application, further comprising a heat radiation layer including a cooling channel formed by additive manufacturing.         The target material for a neutron generating device according to item 7 of the scope of the patent application, wherein the base layer is made of a material that suppresses foaming, and the heat dissipation layer is made of a thermally conductive material The material is made of foam material. The material that suppresses foaming or the material that can both conduct heat and foam includes at least one of Fe, Ta, or V. The thermally conductive material includes at least one of Cu, Fe, and Al. The heat dissipation layer and The base layer is connected by a HIP process.         The target material for a neutron generating device according to item 7 of the scope of the patent application, wherein the heat dissipation layer and the base layer are at least partially the same material or integrated, and the same material is Ta or Ta- W alloy.         A neutron capture treatment system includes a neutron generating device and a beam shaper. The neutron generating device includes an accelerator and a target. The charged particle beam generated by the accelerator accelerates to generate a neutron beam by interacting with the target. The shaping body includes a reflector, a retarder, a thermal neutron absorber, a radiation shield, and a beam exit. The retarder reduces the neutrons generated from the target to the superthermal neutron energy region, and the reflector surrounds the retarder. Speeding the body and directing the deviating neutrons back to the retarding body to increase the intensity of the superheated neutron beam. The thermal neutron absorber is used to absorb thermal neutrons to avoid excessive doses with shallow normal tissue during treatment. The radiation shield The body is arranged around the beam exit at the rear of the reflector for shielding leaked neutrons and photons to reduce the normal tissue dose in the non-irradiated area, wherein the target is as described in one of items 1-9 of the scope of patent application .