WO2019114307A1 - 中子捕获治疗系统 - Google Patents

中子捕获治疗系统 Download PDF

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Publication number
WO2019114307A1
WO2019114307A1 PCT/CN2018/100787 CN2018100787W WO2019114307A1 WO 2019114307 A1 WO2019114307 A1 WO 2019114307A1 CN 2018100787 W CN2018100787 W CN 2018100787W WO 2019114307 A1 WO2019114307 A1 WO 2019114307A1
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WIPO (PCT)
Prior art keywords
retarding
neutron
cooling
target
end surface
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PCT/CN2018/100787
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English (en)
French (fr)
Inventor
刘渊豪
卢威骅
Original Assignee
南京中硼联康医疗科技有限公司
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Priority claimed from CN201721763785.3U external-priority patent/CN208114948U/zh
Priority claimed from CN201711347618.5A external-priority patent/CN109925606B/zh
Application filed by 南京中硼联康医疗科技有限公司 filed Critical 南京中硼联康医疗科技有限公司
Priority to EP18889562.7A priority Critical patent/EP3708224B1/en
Priority to JP2020530377A priority patent/JP6947933B2/ja
Publication of WO2019114307A1 publication Critical patent/WO2019114307A1/zh
Priority to US16/880,161 priority patent/US11266859B2/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N5/1077—Beam delivery systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N5/1042—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy with spatial modulation of the radiation beam within the treatment head
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H3/00—Production or acceleration of neutral particle beams, e.g. molecular or atomic beams
    • H05H3/06—Generating neutron beams
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H6/00—Targets for producing nuclear reactions
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1085—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy characterised by the type of particles applied to the patient
    • A61N2005/109—Neutrons
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1092—Details
    • A61N2005/1094—Shielding, protecting against radiation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1092—Details
    • A61N2005/1095—Elements inserted into the radiation path within the system, e.g. filters or wedges
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1092—Details
    • A61N2005/1098—Enhancing the effect of the particle by an injected agent or implanted device
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
    • G21F3/00—Shielding characterised by its physical form, e.g. granules, or shape of the material
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21G—CONVERSION OF CHEMICAL ELEMENTS; RADIOACTIVE SOURCES
    • G21G4/00—Radioactive sources
    • G21G4/02—Neutron sources
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating

Definitions

  • the present invention relates to a radioactive ray irradiation system, and more particularly to a neutron capture treatment system.
  • neutron capture therapy combines the above two concepts, such as boron neutron capture therapy, by the specific agglomeration of boron-containing drugs in tumor cells, combined with precise neutron beam regulation, providing better radiation than traditional radiation. Cancer treatment options.
  • boron neutron capture therapy depends on the concentration of boron-containing drugs and the number of thermal neutrons in the tumor cell position, it is also called binary cancer therapy; thus, in addition to the development of boron-containing drugs, The improvement of flux and quality of neutron source plays an important role in the study of boron neutron capture therapy.
  • an embodiment of the present application provides a neutron capture treatment system including a beam shaping body, a vacuum tube disposed in the beam shaping body, the beam shaping body including a beam inlet, and a housing a accommodating cavity of the vacuum tube, a retarding body adjacent to the end of the accommodating cavity, a reflector surrounded by the retarding body, a radiation shield disposed in the beam shaping body, and a beam outlet, the target of the vacuum tube is provided with a target, the target and the target
  • the charged particle beam incident from the beam entrance undergoes a nuclear reaction to generate neutrons, the neutron forms a neutron beam, the neutron beam exits the beam exit and defines a neutron beam axis, and the retarding body is self-targeted
  • the generated neutrons are decelerated to the superheated neutron energy region, and the reflector directs the deviated neutrons back to the retarding body to increase the intensity of the epithermal neutron beam, which is used to shield the leaking neutrons and photo
  • the retarding body includes two cylindrical slow-moving bodies having different outer diameters, and the target is accommodated in the retarding body, which can reduce the material cost and Greatly reduce the intensity of fast neutrons and improve the quality of neutron beams.
  • the retarding body includes a first retarding body adjacent to the beam inlet and a second retarding body closely contacting the first retarding body and close to the beam outlet, the first retarding body including at least two outer diameters
  • the different cylindrical relief bodies, the beam inlet, the retarding body and the beam outlet all extend along the neutron beam axis, and the distance from the target to the beam exit is smaller than the distance from the first end to the beam exit.
  • the first retarding body includes three cylindrical retarding bodies having different outer diameters, and the first retarding body includes a first retarding portion close to the beam inlet and a first close fitting portion with the first retarding portion. a second retarding portion and a third retarding portion closely contacting the second retarding portion, wherein the first, second, and third retarding portions are sequentially arranged in the direction of the neutron beam axis, first, second, and third
  • the outer diameters of the retarding portion and the second retarding body are first, second, third, and fourth outer diameters, respectively, the first outer diameter is smaller than the second outer diameter, and the second outer diameter is smaller than the third outer diameter, and the third The outer diameter is equal to the fourth outer diameter.
  • the first retarding portion has a first front end surface adjacent to the beam inlet, a first rear end surface close to the beam outlet, and a first outer circumferential surface;
  • the second retarding portion has a close fit with the first rear end surface a second front end surface, a second rear end surface adjacent to the beam outlet, and a second outer circumferential surface;
  • the third retarding portion has a third front end surface closely fitting with the second rear end surface, and a third rear end surface close to the beam outlet And a third outer circumferential surface;
  • the second retarding body has a fourth front end surface closely contacting the third rear end surface, a fourth rear end surface adjacent to the beam outlet, and a fourth outer circumferential surface, first, second, and 3.
  • the fourth front end surface and the first, second, third, and fourth rear end surfaces are parallel to each other and are perpendicular to the neutron beam axis, and the cut surface passing through the neutron beam axis and the first outer circumferential surface
  • the intersection line is perpendicular to the second front end surface, and the intersection of the section passing through the neutron beam axis and the second outer circumferential surface is perpendicular to the third front end surface.
  • the first front end surface intersects the first outer circumferential surface to obtain a first intersection
  • the second front end surface intersects the second outer circumferential surface to obtain a second intersection
  • the third front end The face intersects with the third outer circumferential surface to obtain a third intersection
  • the first, second, and third intersections are on the same straight line.
  • the reflection compensation body is filled between the accommodating cavity and the vacuum tube, and the reflection compensation body is lead or Al or Teflon or C.
  • the first end protrudes from the target in the direction of the beam entrance along the neutron beam axis
  • the second end protrudes from the target in the direction of the beam exit along the neutron beam axis.
  • the reflector protrudes from the retarder body on both sides of the neutron beam axis
  • the accommodating cavity includes a reflector accommodating cavity surrounded by the reflector and extends from the reflector accommodating cavity by the retarding body
  • the retarding body accommodating cavity comprises a extending portion accommodated in the reflector accommodating cavity and an embedding section extending from the extending section and accommodated in the retarding body accommodating cavity, and the target is disposed at an end of the embedding section.
  • the neutron capture treatment system further comprises at least one cooling device
  • the beam shaping body is provided with at least one receiving duct for accommodating the cooling device
  • the lead device is filled with a lead alloy or an aluminum alloy between the cooling device and the inner wall of the receiving duct.
  • the neutron capture treatment system further includes a shield disposed at the beam entrance and closely fitted to the beam shaping body.
  • the “cone” or “taper” as used in the embodiment of the present application refers to a structure in which the overall tendency of the outer contour is gradually reduced from one side to the other side in the illustrated direction, and the entire surface of the outer contour may be It is a smooth transition, or it can be a non-smooth transition, such as a lot of protrusions and grooves on the surface of the cone.
  • FIG. 1 is a schematic diagram of a neutron capture treatment system in the first embodiment of the present application, wherein the second cooling portion and the third cooling portion of the cooling device are parallel to the neutron beam axis;
  • FIG. 2 is a schematic diagram of a neutron capture treatment system without a reflection compensation body and a reflection compensation in the first embodiment of the present application;
  • Figure 3 is a cross-sectional view of the neutron capture treatment system along the axis of the neutron beam and passing through the second retarding portion of Figure 1 in the first embodiment of the present application;
  • FIG. 4 is a schematic diagram of a neutron capture treatment system in the second embodiment of the present application, wherein the retarding body is disposed as a double-cone slow-acting body;
  • FIG. 5 is a partially enlarged schematic view showing a cooling device of a neutron capture treatment system according to Embodiments 1 and 2 of the present application;
  • FIG. 6 is a schematic diagram of a neutron capture treatment system in a third embodiment of the present application, wherein the second cooling portion and the third cooling portion of the cooling device are perpendicular to the neutron beam axis;
  • FIG. 7 is a schematic structural view of a target in a neutron capture treatment system in an embodiment of the present application.
  • FIG. 8 is a schematic diagram of a neutron capture treatment system in which the cooling device is removed and the target does not protrude into the retarding body in the fourth embodiment of the present application;
  • FIG. 9 is a schematic diagram of a neutron capture treatment system in which a cooling device is removed and a first slow-moving body is a stepless retarding body in Embodiment 5 of the present application;
  • FIG. 10 is a schematic diagram of a neutron capture treatment system in which a cooling device is removed and a first slow-moving body is a second-order retarding body in Embodiment 6 of the present application;
  • FIG. 11 is a schematic diagram of a neutron capture treatment system in which a cooling device is removed and a first retarding body is a fourth-order retarding body in Embodiment 7 of the present application;
  • FIG. 12 is a schematic diagram of a neutron capture treatment system in which a cooling device is removed and a first slow-moving body is a 10th-order retarding body in Embodiment 8 of the present application;
  • Neutron capture therapy has been increasingly used as an effective means of treating cancer in recent years, with boron neutron capture therapy being the most common, and neutrons supplying boron neutron capture therapy can be supplied by nuclear reactors or accelerators.
  • Embodiments of the present application take the accelerator boron neutron capture treatment as an example.
  • the basic components of the accelerator boron neutron capture treatment typically include an accelerator, a neutron generator, and a heat for accelerating charged particles (eg, protons, helium nuclei, etc.). Remove the system and the beam shaping body.
  • the accelerated charged particles and the metal neutron generating portion generate neutrons, and are selected according to the required neutron yield and energy, the energy and current of the accelerated charged particles, and the physicochemical properties of the metal neutron generating portion.
  • Nuclear reaction The nuclear reactions that are often discussed are 7 Li(p,n) 7 Be and 9 Be(p,n) 9 B. Both reactions are endothermic.
  • 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 the superthermal neutron of the keV energy level, theoretically, if a proton is used to bombard the metal lithium neutron generator with energy slightly above the threshold, relatively low energy neutrons can be generated.
  • the proton interaction cross section between the two neutron generating parts and the threshold energy of lithium metal (Li) and base metal (Be) is not high, in order to generate a sufficiently large neutron pass. Amount, usually a higher energy proton is used to initiate the nuclear reaction.
  • the ideal target should have a high neutron yield, produce a neutron energy distribution close to the epithermal neutron energy zone (described in detail below), no excessively strong radiation generation, safe and inexpensive to operate, and high temperature resistance. But in fact, it is impossible to find a nuclear reaction that meets all requirements.
  • a target made of lithium metal is used in the embodiment of the present application. However, it is well known to those skilled in the art that the material of the target can also be made of other metallic materials than the metal materials discussed above.
  • the requirements for the heat removal system vary depending on the selected nuclear reaction.
  • 7 Li(p,n) 7 Be has a lower melting point and thermal conductivity coefficient of the metal target (lithium metal), and the requirements for the heat removal system are higher.
  • 9 Be(p,n) 9 B is high.
  • a nuclear reaction of 7 Li(p,n) 7 Be is employed in the examples of the present application. It can be seen that the temperature of the target irradiated by the accelerated charged particle beam of high energy level is inevitably increased, thereby affecting the service life of the target.
  • the nuclear reaction of the nuclear reactor or the charged particles of the accelerator and the target produces a mixed radiation field, that is, the beam contains low-energy to high-energy neutrons and photons.
  • the more radiation content in addition to the superheated neutrons, the greater the proportion of non-selective dose deposition in normal tissues, so these will cause unnecessary doses of radiation to be minimized.
  • the human head tissue prosthesis is used for dose calculation in the embodiment of the present application, and the prosthetic beam quality factor is used as the neutron shot. The design reference for the bundle will be described in detail below.
  • the International Atomic Energy Agency has given five air beam quality factor recommendations for clinical neutron sources for clinical boron neutron capture therapy. These five recommendations can be used to compare the pros and cons of different neutron sources and provide The reference basis for selecting the neutron generation route and designing the beam shaping body.
  • the five recommendations are as follows:
  • Epithermal neutron beam flux Epithermal neutron flux>1x 10 9 n/cm 2 s
  • the superheated neutron energy region is between 0.5eV and 40keV, the thermal neutron energy region is less than 0.5eV, and the fast neutron energy region is greater than 40keV.
  • the neutron beam flux and the concentration of boron-containing drugs in the tumor determine the clinical treatment time. If the concentration of the boron-containing drug in the tumor is high enough, the requirement for the flux of the neutron beam can be reduced; conversely, if the concentration of the boron-containing drug in the tumor is low, a high-flux superheated neutron is required to give the tumor a sufficient dose.
  • the IAEA's requirement for the epithermal neutron beam flux is that the number of epithermal neutrons per square centimeter per second is greater than 10 9 .
  • the neutron beam at this flux can roughly control the treatment of current boron-containing drugs. In one hour, short treatment time, in addition to the advantages of patient positioning and comfort, can also make more effective use of boron-containing drugs in the tumor for a limited residence time.
  • fast neutron contamination is defined as the fast neutron dose accompanying the unit's superheated neutron flux.
  • the IAEA's recommendation for fast neutron contamination is less than 2x 10 -13 Gy-cm 2 /n.
  • ⁇ -rays are strong radiation, which will non-selectively cause dose deposition of all tissues in the beam path. Therefore, reducing ⁇ -ray content is also a necessary requirement for neutron beam design.
  • ⁇ -ray pollution is defined as the unit of superheated neutron flux.
  • the gamma dose is recommended by IAEA for gamma ray contamination to be less than 2 x 10 -13 Gy-cm 2 /n.
  • thermal neutrons Due to the fast decay rate and poor penetrability of thermal neutrons, most of the energy is deposited on the skin tissue after entering the human body. In addition to melanoma and other epidermal tumors, thermal neutrons are needed as the neutron source for boron neutron capture therapy. Deep tumors such as tumors should reduce the thermal neutron content.
  • the IAEA's ratio of thermal neutron to superheated neutron flux is recommended to be less than 0.05.
  • the ratio of neutron current to flux represents the directionality of the beam. The larger the ratio, the better the forward neutron beam, and the high forward neutron beam can reduce the surrounding normal tissue dose caused by neutron divergence. It also increases the elasticity of the treatment depth and posture.
  • the IAEA's ratio of neutron current to flux is recommended to be greater than 0.7.
  • the neutron capture treatment system 1 includes a beam shaping body 10, a cooling device 20 provided in the beam shaping body 10, a vacuum tube 30, and a shield provided outside the beam shaping body 10 and closely attached to the beam shaping body 10. Body 40.
  • the beam shaping body 10 includes a beam inlet 11, a housing chamber 12 for accommodating the vacuum tube 30, a housing tube 13 for accommodating the cooling device 20, and a contiguous end adjacent to the end of the housing chamber 12.
  • the end of the vacuum tube 30 is provided with a target 31 which undergoes a nuclear reaction with a charged particle beam incident from the beam inlet 11 and passing through the vacuum tube 30 to generate a neutron, the neutron forms a neutron beam, and the neutron beam is self-generated.
  • the beam exit 18 exits and defines a neutron beam axis X1 that coincides with the central axis of the vacuum tube 30.
  • the retarding body 14 decelerates the neutrons generated from the target 31 to the superheated neutron energy region, and the reflector 15 directs the neutrons deviating from the neutron beam axis X1 back to the retarding body 14 to enhance the superheated neutron beam. Beam strength.
  • the reflector 15 protrudes from the retarding body 14 on both sides of the neutron beam axis X1.
  • the thermal neutron absorber 16 is used to absorb thermal neutrons to avoid excessive doses with shallow normal tissue during treatment.
  • Radiation shield 17 is used to shield leaking neutrons and photons to reduce the normal tissue dose in the non-irradiated area.
  • the accelerator neutron capture treatment system accelerates the charged particle beam by an accelerator.
  • the target 31 is made of lithium metal, specifically, lithium metal having a 7 Li content of 98% and a 6 Li content of 2%.
  • the charged particle beam is accelerated to an energy sufficient to overcome the Coulomb repulsion of the target nucleus, and a 7 Li(p,n) 7 Be nuclear reaction occurs with the target 31 to generate neutrons, and the beam shaping body 10 can slow the neutron to Ultra-heat neutron energy zone and reduce thermal neutron and fast neutron content.
  • the retarding body 14 is made of a material having a large cross section with fast neutron action and a small cross section of superheated neutrons, and the reflector 15 is made of a material having strong neutron reflection ability, and the thermal neutron absorber 16 is composed of heat and heat. Made of a material with a large cross section.
  • the retarding body 14 is made of MgF 2 and a mixture of LiF which accounts for 4.6% by weight of MgF 2
  • the reflector 15 is made of Pb
  • the thermal neutron absorber 16 is made of 6 Li.
  • the radiation shield 17 includes a photon shield 171 and a neutron shield 172.
  • the radiation shield 17 includes a photon shield 171 made of lead (Pb) and a neutron shield 172 made of polyethylene (PE).
  • the target 31 includes a lithium target layer 311 and an oxidation resistant layer 312 on the side of the lithium target layer 311 for preventing oxidation of the lithium target layer 311.
  • the oxidation resistant layer 312 of the target 31 is made of Al or stainless steel.
  • the retarding body 14 includes a first retarding body 140 adjacent to the beam inlet 11 and a second retarding body 144 closely attached to the first retarding body 140 and adjacent to the beam outlet 18.
  • the velocity body 14 has a first end 146 near the beam inlet 11, a second end 148 near the beam outlet 18, and a third end 147 between the first end 146 and the second end 148, The three end portions 147 are located between the first retarding body 140 and the second retarding body 144.
  • the beam inlet 11, the retarding body 14 and the beam outlet 18 all extend along the neutron beam axis X1, and the distance of the target 31 to the beam outlet 18 is smaller than the distance from the first end 146 to the beam outlet 18, In other words, the first end 146 protrudes from the target 31 along the neutron beam axis X in the direction of the beam inlet 11, and the second end 148 protrudes in the direction of the beam outlet 18 along the neutron beam axis X1.
  • the first retarding body 140 is composed of at least two hollow cylindrical slow bodies having different outer diameters and inner diameters. Referring to FIGS.
  • the first retarding body 140 is formed of three hollow cylinders having different outer diameters and the same inner diameter.
  • the retarding body composition, the first retarding body 140 and the second retarding body 144 are formed by laminating and splicing a plurality of slow-moving bodies formed from a mold of a corresponding size by a process such as polishing or grinding.
  • the first retarding body 140 includes a first retarding portion 141 near the beam inlet 11 , a second retarding portion 142 located on the right side of the first retarding portion 141 and closely fitting with the first retarding portion 141 .
  • a third retarding portion 143 located on the right side of the second retarding portion 142 and in close contact with the second retarding portion 142, that is, the first, second, and third retarding portions 141, 142, and 143 Arranged in the direction of the neutron beam axis X1.
  • the outer diameters of the first, second, and third retarding portions 141, 142, 143 and the second retarding body 144 are respectively the first, second, third, and fourth outer diameters, and the first outer diameter is smaller than the second outer diameter.
  • the diameter, the second outer diameter is smaller than the third outer diameter
  • the third outer diameter is equal to the fourth outer diameter
  • the inner diameters of the first, second, and third retarding portions 141, 142, and 143 are equal.
  • the central axes of the first, second, and third retarding portions 141, 142, and 143 coincide with the center line of the second retarding body 144, and the central axis also coincides with the neutron beam axis X1.
  • the first retarding portion 141 has a first front end surface 1411 on the left side, a first rear end surface 1412 on the right side, a first outer circumferential surface 1413, and a first inner circumferential surface 1414.
  • the second retarding portion 142 has a left side. a second front end surface 1421 on the side, a second rear end surface 1422 on the right side, a second outer circumferential surface 1423, and a second inner circumferential surface 1424.
  • the third retarding portion 143 has a third front end surface 1431 located on the left side. a third rear end surface 1432, a third outer circumferential surface 1433 and a third inner circumferential surface 1434 on the right side; the second retarding body 144 has a fourth front end surface 1441 on the left side, a fourth rear end surface 1442 on the right side, and The fourth outer circumferential surface 1443.
  • the first, second, third, and fourth front end faces 1411, 1421, 1431, and 1441 and the first, second, third, and fourth rear end faces 1412, 1422, 1432, and 1442 are parallel to each other and are neutrons
  • the beam axis X1 is perpendicular, the first rear end surface 1412 of the first retarding portion 141 is in close contact with the second front end surface 1421 of the second retarding portion 142, and the second rear end surface 1422 and the third portion of the second retarding portion 142 are third.
  • the third front end surface 1431 of the retarding portion 143 is in close contact with each other, and the third rear end surface 1432 of the third retarding portion 143 is in close contact with the fourth front end surface 1441 of the second retarding body 144.
  • the intersection of the section passing through the neutron beam axis X1 and the first outer circumferential surface 1413 is perpendicular to the second front end surface 1421, and the intersection of the section passing through the neutron beam axis X1 and the second outer circumferential surface 1423
  • the three front end faces 1431 are perpendicular, and the third outer circumferential surface 1433 of the third retarding portion and the fourth outer circumferential surface 1443 of the second retarding body 144 are smoothly transitioned.
  • the first front end surface 1411 of the first retarding portion 141 intersects the first outer circumferential surface 1413 to obtain a first intersection 1410, and a second retarding portion.
  • the second front end surface 1421 of the 142 intersects with the second outer circumferential surface 1423 to obtain a second intersection 1420, and the third front end surface 1431 of the third retarding portion 143 intersects with the third outer circumferential surface 1433 to obtain a third intersection 1430.
  • the second and third intersections 1410, 1420, 1430 are located on the same line X2, and the angle between the line X2 and the neutron beam axis X1 is less than 90 degrees.
  • the reflector 15 has an inner surface 150 surrounding the retarding body 14 .
  • the third front end surface 1431, the third outer circumferential surface 1433, the fourth rear end surface 1442, and the fourth outer circumferential surface 1443 are in close contact with each other.
  • the first retarding body 140 is composed of three concentric hollow cylinders having different outer diameters and the same inner diameter.
  • a slow-acting body composition, the outer contours of the first, second, and third retarding portions 141, 142, and 143 are combined in a stepped shape as viewed in a direction perpendicular to the neutron beam axis X1, thereby A slow speed body 140 is named as a 3 step slow speed body.
  • the first retarding body 140 is composed of two, four, and ten hollow cylindrical slow-moving bodies having different outer diameters and inner diameters.
  • the first retarding body 140 may be a second-order, fourth-order, and ten-step retarding body. In other embodiments, the first retarding body 140 may also be hollowed by other numbers of outer diameters and inner diameters. Cylindrical slow-moving bodies, such as 12, 15, etc.
  • the second retarding body 144 may also be arranged as a stepped slow-moving body; or a polygonal prism may be used instead of the cylindrical forming slow-moving body; in addition, the first, second, and third intersections 1410, 1420, 1430 may not be on the same straight line, may be located on an arc; in addition, the slow speed portion constituting the first retarding body 140 may be set as a partially non-hollow structure according to actual needs; The central axis of each retarding portion of 140 and the central axis of the second retarding body 14 may not coincide with each other.
  • the retarding body is formed by laminating and splicing a plurality of slow-moving bodies formed from a mold of a corresponding size by a process such as polishing, grinding, etc., and the slow-moving body formed from the grinding tool is a disc-shaped body, and the retarding body is used as a slow-moving body.
  • the volume of the slow-moving body material consumed is the product of the dimension of the retarding body in the direction of the neutron beam axis X1 and the bottom area of the disk.
  • the cone-shaped slow-moving body is made of a cylindrical slow-moving body, that is, the volume of the material required for designing the slow-moving body into a cylindrical shape or a cone shape is the same.
  • the first retarding body 140 is designed as a stepped slow-moving body, and the composition of the retarding body in the direction of the neutron beam axis X1 and the maximum diameter of the slow-moving body are unchanged.
  • the bottom area of the slow-speed disc-shaped retarding body is gradually increased.
  • the slow-moving body material required for designing the retarding body as the step-shaped slow-moving body is smaller than designing the slow-moving body as a whole.
  • the material required for a cylindrical or pyramidal slowing body It can be seen from this that the stepped retarder of the present application can greatly reduce the material for manufacturing the retarding body, thereby reducing the manufacturing cost.
  • the accommodating chamber 12 is a cylindrical cavity surrounded by the reflector 15 and the first retarding body 140 of the retarding body 14.
  • the accommodating cavity 12 includes a reflector accommodating cavity 121 surrounded by the reflector 15 and a retarding body accommodating cavity 122 extending from the reflector accommodating cavity 121 and extending from the first retarding body 140 of the retarding body 14 . That is, the retarding body accommodating chamber 122 is surrounded by the first, second, and third inner circumferential surfaces 1414, 1424, and 1434 of the first, second, and third retarding portions 141, 142, and 143.
  • the vacuum tube 30 includes an extending portion 32 surrounded by the reflector 15 and an embedded portion 34 extending from the extending portion 32 and embedded in the retarding body 14.
  • the extending portion 32 is received in the reflector receiving chamber 121, and the embedded portion 34 is accommodated in the retarding body receiving chamber. 122 inside.
  • the target 31 is provided at an end of the insertion section 34 of the vacuum tube 30, and the end is flush with the third rear end surface 1432 of the first retarding body 140.
  • the vacuum tube 30 is partially embedded in the retarding body 14, that is, the target 31 is disposed in the retarding body 14.
  • the depth at which the target 31 projects into the retarding body 14 is marked X, and the value of X is equal to the size of the retarding body receiving cavity 122 in the direction of the neutron beam axis X1, that is, in the direction of the neutron beam axis X1.
  • the size of the first retarding body 140 is marked X, and the value of X is equal to the size of the retarding body receiving cavity 122 in the direction of the neutron beam axis X1, that is, in the direction of the neutron beam axis X1.
  • the depth X of the target 31 extending into the retarding body 14 may be smaller or larger than the dimension of the first retarding body 140 in the direction of the neutron beam axis X1, that is, the target 31 may be disposed in the neutron.
  • the beam axis X1 extends no more than the first retarding body 140 or extends beyond the first retarding body 140 and extends into the second retarding body 144. Accordingly, when the target 31 is disposed at the neutron beam axis X1 When the direction does not extend beyond the first retarding body 140, the first retarding body 140 is disposed in a partially non-hollow structure, and the target 31 is disposed to extend beyond the first retarding body 140 in the direction of the neutron beam axis X1.
  • the first retarding body 140 has a hollow structure
  • the second retarding body 144 has a partially hollow structure.
  • FIG. 1 there is a gap between the accommodating chamber 12 and the vacuum tube 30, and the gap is filled with a reflection compensator 50 which is a Pb or Al capable of absorbing or reflecting neutrons or Teflon or C.
  • the reflection compensating body 50 is capable of reflecting neutrons reflected or scattered into the gap into the retarding body 14 or the reflector 15, thereby increasing the intensity of the epithermal neutrons and reducing the time required for the irradiated body to be irradiated.
  • avoiding neutron leakage to the outside of the beam shaping body 10 adversely affects the device of the neutron capture treatment system and improves radiation safety.
  • the receiving duct 13 includes second and third receiving ducts 132, 133 extending in the direction of the neutron beam axis X1 and disposed on both sides of the accommodating chamber 12 and spaced apart by 180°, and disposed in the middle
  • the first receiving duct 131 is located in a plane perpendicular to the sub-beam axis X1 and between the target 31 and the retarding body 14.
  • the second and third receiving ducts 132, 133 extend beyond the accommodating chamber 12 in the direction of the neutron beam axis X1 and are in communication with the first accommodating duct 131, respectively.
  • the first receiving duct 131 is located at the end of the accommodating chamber 12 and is located between the target 31 and the retarding body 14, and the second accommodating duct 132 and the third accommodating duct 133 are respectively located on both sides of the accommodating chamber 12 and respectively It communicates with the first accommodation duct 131 so that the entire accommodation duct 30 is disposed in a " ⁇ " type structure.
  • the second and third receiving ducts 132, 133 respectively include second and third reflector receiving ducts 1321 and 1331 located outside the reflector receiving chamber 121 and respectively from the second and third reflector receiving ducts.
  • the second and third retarding portion accommodating pipes 1322 and 1332 extending in the outer side of the retarding body accommodating chamber 122 are defined by the members 1331 and 1331.
  • the second and third receiving ducts 132, 133 extend in the direction of the neutron beam axis X1 and are parallel to the neutron beam axis X1, that is, the second and third receiving ducts 132, 133 and the neutron beam.
  • the angle between the axes X1 is 0°.
  • the second and third receiving ducts 132 and 133 are not in communication with the accommodating chamber 12, that is, the reflector 15 and the retarding body 14 are disposed between the second and third accommodating ducts 132 and 133 and the accommodating chamber 12. Separated. In other embodiments, the second and third receiving ducts 132, 133 are in communication with the accommodating chamber 12, that is, the outer surface portion of the vacuum tube 30 accommodated in the accommodating chamber 12 is partially exposed in the second and third accommodating tubes 132, 133. In summary, the second and third receiving ducts 132, 133 are located outside the inner wall of the accommodating chamber 12.
  • the second and third receiving ducts 132 and 133 are disposed in a circular arc-shaped duct extending along the axial direction of the vacuum tube 30. In other embodiments, a square, triangular or other polygonal duct may be used instead.
  • the second and third receiving ducts 132, 133 are two receiving ducts which are spaced apart from each other in the circumferential direction of the accommodating chamber 12, and in other embodiments, the second and third accommodating ducts 132 133 is communicated in the circumferential direction of the accommodating chamber 12, that is, by a receiving duct that surrounds the accommodating chamber 12.
  • the cooling device 20 includes a first cooling portion 21 arranged in the vertical direction and located in front of the target 31 for cooling the target 31, extending in the direction of the neutron beam axis X1 and located on both sides of the vacuum tube 30.
  • the first cooling portion 21 is connected between the second and third cooling portions 22, 23 in parallel with the second cooling portion 22 and the third cooling portion 23 of the neutron beam axis X1.
  • the first cooling portion 21 is housed in the first housing duct 131 arranged in a direction perpendicular to the neutron beam axis X1, and the second and third cooling portions 22, 23 are respectively accommodated in the direction along the neutron beam axis X1.
  • the second and third receiving ducts 132, 133 are disposed.
  • the second cooling unit 22 inputs a cooling medium to the first cooling unit 21, and the third cooling unit 23 outputs the cooling medium in the first cooling unit 21.
  • the first cooling unit 21 is located between the target 31 and the retarding body 14, and one side of the first cooling unit 21 is in direct contact with the target 31, and the other side is in contact with the retarding body 14.
  • the second cooling portion 22 and the third cooling portion 23 respectively include first and second cooling sections 221 and 231 located outside the reflector accommodating chamber 121 and extending from the first and second cooling sections 221 and 231 and located at the slow speed body.
  • the third and fourth cooling sections 222, 232 outside the cavity 122.
  • the third and fourth cooling sections 222 and 232 are respectively in communication with the first cooling unit 21.
  • the first cooling portion 21 is located at the end of the insertion section 121 of the vacuum tube 30 on the side of the target 31 and is in direct contact with the target 31, and the second cooling portion 22 and the third cooling portion 23 are respectively accommodated in the accommodation.
  • the upper and lower sides of the vacuum tube 30 in the chamber 12 are respectively in communication with the first cooling portion 21, so that the entire cooling device 20 is disposed in a " ⁇ " type structure.
  • the first cooling portion 21 is in planar contact with the target 31, and the second cooling portion 22 and the third cooling portion 23 are both tubular structures made of copper, and the second cooling portion 22 and the third cooling portion 23 are It extends in the direction of the neutron beam axis X1 and is parallel to the neutron beam axis X1, that is, the angle between the second cooling portion 22 and the third cooling portion 23 and the neutron beam axis X1 is 0°.
  • the first cooling portion 21 includes a first contact portion 211, a second contact portion 212, and a cooling groove 213 between the first contact portion 211 and the second contact portion 212 through which the cooling medium passes.
  • the first contact portion 211 is in direct contact with the target 31, and the second contact portion 212 may be in direct contact with the retarding body 14 or may be indirectly contacted by air.
  • the cooling tank 213 has an input groove 214 that communicates with the second cooling unit 22 and an output groove 215 that communicates with the third cooling unit 23 .
  • the first contact portion 211 is made of a heat conductive material.
  • the upper edge of the input groove 214 is located above the upper edge of the second cooling portion 22, and the lower edge of the output groove 215 is located below the lower edge of the third cooling portion 23.
  • the advantage of this arrangement is that the cooling device 20 can smoothly input the cooling water into the cooling tank 213 and cool the target 31 in a timely manner, and the heated cooling water can be smoothly discharged from the cooling tank 213. At the same time, it is also possible to reduce the water pressure of the cooling water in the cooling tank 213 to some extent.
  • the first contact portion 211 is made of a heat conductive material (such as a material having good thermal conductivity such as Cu, Fe, Al, etc.) or a material capable of both heat conduction and foaming inhibition
  • the second contact portion 212 is made of a material that suppresses foaming.
  • the material for suppressing foaming or the material capable of both heat conduction and foaming inhibition is made of any one of Fe, Ta or V.
  • the target 31 is heated by an accelerated irradiation temperature increase of a high energy level, and the first contact portion 211 derives heat and carries the heat out by the cooling medium flowing through the cooling bath 213, thereby cooling the target 31.
  • the cooling medium is water.
  • the shield 40 covers the left end surface of the beam shaping body 10 and is in close contact with the end surface to prevent the neutron beam and gamma rays formed at the target 31 from overflowing from the left end surface of the beam shaping body 10.
  • the shield 40 is composed of Pb and PE.
  • the shield 40 is composed of at least two layers of Pb and at least one layer of PE.
  • the shield 40 includes a first Pb layer 41 closely attached to the left end surface of the beam shaping body 10, a PE layer 42 closely attached to the first Pb layer 41, and a cover PE layer 42 and PE.
  • the layer 42 is in close contact with the second Pb layer 43.
  • Pb is capable of absorbing gamma rays overflowing from the beam shaping body 10 and reflecting neutrons overflowing from the beam shaping body 10 back to the retarding body 14 to increase the intensity of the epithermal neutron beam.
  • the retarding body 14 is partially composed of a multi-step retarding body.
  • Composition in the fifth embodiment, as shown in FIG. 9, the retarding body 14 is composed of an entire cylindrical slow-moving body.
  • the retarding body 14 can also be a cone-shaped speeding body and a
  • the cylindrical slow-moving body composition may also be composed of two tapered slow-acting bodies in the second embodiment shown in FIG.
  • the retarding body 14' is composed of two inverted cones.
  • the retarding body 14' in the second embodiment is referred to as a double-cone slowing body.
  • the retarding body 14' has a first end 141', a second end 142' and a third end 143' between the first end 141' and the second end 142'.
  • the first, second, and third end portions 141', 142', 143' have a circular cross section, and the first end portion 141' and the second end portion 14'2 have a smaller diameter than the third end portion 143'. diameter.
  • a first tapered body 146' is formed between the first end portion 141' and the third end portion 143', and a second tapered body 148' is formed between the third end portion 143' and the second end portion 142'.
  • the target 31 is housed within the first tapered body 142'.
  • the angle between the second and third receiving ducts 132, 133 and the second and third cooling portions 22, 23 and the neutron beam axis X1 is 0°. In other embodiments, the angle between the second and third receiving ducts 132, 133 and the second and third cooling portions 22, 23 and the neutron beam axis X1 may be other than 0 degrees and less than or equal to 180 degrees. Any angle, for example, as shown in FIG. 6, the angle between the second and third receiving ducts 132', 133' and the second and third cooling portions 22', 23' and the neutron beam axis X1 is 90. °.
  • the neutron capture treatment system 1" in the third embodiment of the present application is disclosed, wherein the second cooling portion 22' and the third cooling portion 23' of the cooling device 20' and the neutron beam axis X1 are shown.
  • the cooling device 20' is disposed in an "I" type structure to cool the target 31 in the embedded vacuum tube 30.
  • the first cooling portion 21' in the "I" type cooling device 20' is the first type of cooling device
  • the first cooling portion 21 of 20 is disposed the same except that the second cooling portion 22' and the third cooling portion 23' of the "I" type cooling device 20' and the first cooling portion 21' are located in the neutron beam.
  • the second cooling portion 22' and the third cooling portion 23' respectively pass through the retarding body 14' in the direction perpendicular to the neutron beam axis X1, that is, the second cooling portion 22, in the same plane perpendicular to the axis X1'.
  • the angle between the 'and the third cooling portion 23' and the neutron beam axis X1 is 90°, so that the entire cooling device is arranged in a rectangular shape, that is, the above-mentioned "I" type structure.
  • the pipe 30' is also set to an "I” type structure, and the first receiving pipe 131' of the "I" type receiving pipe 30' is provided.
  • the first accommodation duct 131 of the ⁇ -type cooling duct 30 is disposed the same except that the second accommodating duct 132' and the third accommodating duct 133' of the "I"-type accommodating duct 30' are located with the first accommodating duct 131'.
  • the neutron beam axis X1 is perpendicular to the same plane, and the second receiving duct 132' and the third receiving duct 133' respectively pass through the retarding body 14' in a direction perpendicular to the neutron beam axis X1, that is, the second
  • the angle between the third receiving ducts 132', 133' and the neutron beam axis X1 is 90°, so that the entire receiving duct is arranged in a rectangular shape, that is, the above-mentioned "I" type structure. It is easy to think that in the figure 4 and the structure shown in Fig. 9, the cooling device 20 and the accommodation duct 30 may be provided in an "I" type structure.
  • FIG. 8 is a schematic view of the neutron capture treatment system 1, 1' of Figure 1 or Figure 6 with the cooling device 20, 20' removed and the target 31 not extending into the retarding body 14, the neutron capture treatment system 1 disclosed in Figure 8
  • the target 31 is disposed outside the retarding body 14, that is, the accommodating chamber 12 accommodating the vacuum tube 30 does not extend into the retarding body 14
  • the structure is only surrounded by the reflector 15.
  • the structure of the retarding body 14, the reflector 15, the shield 40, the cooling device 20, 20', the thermal neutron absorber 16, the radiation shield 17, and the like are as shown in Fig. 1 or Fig. 6.
  • the structures disclosed are the same. For related descriptions, please refer to the description of related structures above, and details are not described herein again.
  • FIG. 9 is a schematic diagram of a neutron capture treatment system 1 in which the cooling device 20, 20' is removed and the first retarding body is a stepless retarding body, and the neutron capture treatment system 1 disclosed in FIG. 9 is associated with FIG. 1 or Compared with the disclosed neutron capture treatment system 1, 1", only the first retarding body 140 is replaced by a 3rd-order retarding body to a stepless retarding body, that is, the first retarding body 140 is composed of an outer diameter and The cylindrical slow-moving body 144 is composed of a hollow cylindrical second retarding body having the same outer diameter.
  • the structure is the same as that disclosed in FIG. 1 or FIG. 6. For related description, please refer to the description of related structures above, and details are not described herein again.
  • FIG. 10 is a schematic diagram of a neutron capture treatment system 1 in which the cooling device 20, 20' is removed and the first retarding body is a stepless retarding body, and the neutron capture treatment system 1 and FIG. 1 disclosed in FIG.
  • the first slow-moving body 140 is replaced by a third-order slow-moving body to a second-order slow-speed body, the reflector 15, the shield 40, the cooling device 20,
  • the structure of the 20', the thermal neutron absorber 16, the radiation shield 17, and the like is the same as that disclosed in FIG. 1 or FIG. 6.
  • FIG. 11 is a schematic diagram of a neutron capture treatment system 1 in which the cooling device 20, 20' is removed and the first retarding body is a stepless retarding body, and the neutron capture treatment system 1 disclosed in FIG.
  • the first slow-moving body 140 is replaced by a third-order slow-moving body to a fourth-order slow-speed body, the reflector 15, the shield 40, the cooling device 20,
  • the structure of the 20', the thermal neutron absorber 16, the radiation shield 17, and the like is the same as that disclosed in FIG. 1 or FIG. 6.
  • FIG. 12 is a schematic diagram of a neutron capture treatment system 1 in which the cooling device 20, 20' is removed and the first retarding body is a stepless retarding body, and the neutron capture treatment system 1 disclosed in FIG.
  • the first slow-moving body 140 is replaced by a 3rd-order slow-moving body into a 10th-order slow-speed body, the reflector 15, the shield 40, the cooling device 20,
  • the structure of the 20', the thermal neutron absorber 16, the radiation shield 17, and the like is the same as that disclosed in FIG. 1 or FIG. 6.
  • the second and third cooling portions 22, 23; 22', 23' are respectively associated with the second and third receiving ducts 132, 133; 132', 133'
  • a reflection compensator 80; 80' and the reflection compensator 80; 80' is a substance such as a lead alloy or an aluminum alloy capable of absorbing or reflecting neutrons.
  • the reflection compensator 80; 80' is capable of reflecting neutrons reflected or scattered into the gap into the retarding body 14 or the reflector 15, thereby increasing the yield of the epithermal neutrons and thereby reducing the time required for the irradiated body to be illuminated. .
  • the content of lead in the lead alloy is 85% or more, and the content of aluminum in the aluminum alloy is 85% or more.
  • the following is a simulation experiment to analyze and analyze the superheated neutron flux, fast neutron flux, superheated neutron forward reference value, and gamma ray intensity in the relevant structure of the present application.
  • charged particles The source energy is 2.5 MeV, 10 mA
  • the epithermal neutron flux, fast neutron flux counting surface is located at the beam exit 18 of the beam shaping body 10
  • the diameter of the beam exit 18 is 14 CM
  • the counting surface of the gamma ray intensity The left end face of the beam shaping body 10 is used.
  • the target 31 in the first embodiment is housed in the velocity body 14.
  • the target 31 in the fourth embodiment is disposed outside the retarding body 14, for comparison of the embodiments.
  • the influence of the position of the target 31 in the fourth embodiment on the superheated neutron flux, fast neutron flux and neutron forwardness is obtained by comparing the data of Table 1 through simulation experiments.
  • the thickness of the retarding body 14 refers to the dimension of the retarding body 14 in the direction of the neutron beam axis X1.
  • Table 1 Superheated neutron flux, fast neutron flux and superheated neutron forward reference value of the target contained in the retarded body and set in the retarded body
  • the orientation of the neutrons did not change significantly compared to the inclusion of the target 31 in the retarding body 14 and outside the retarding body 14, and the strength of the fast neutrons was reduced by 12.52%.
  • the intensity of the epithermal neutron beam is only reduced by 1.83%. It can be seen that the arrangement of the target 31 in the retarding body 14 is better than the arrangement in which the target 31 is disposed outside the retarding body 14. It should be noted that the closer the superheated neutron forward reference value is to 1, the better the superheated neutron forwardness.
  • the first retarding body 140 is a third-order retarding body.
  • the first retarding speed is used.
  • the body 140 is respectively set as a stepless, 2nd order, 3rd order, 4th order, 10th order retarding body, in order to compare the first retarding body 140 of different orders to the superheated neutron flux, fast neutron flux and medium
  • the first retarding body 140 is set to be stepless, 2nd order, and 3, respectively, while maintaining the included angle ⁇ and the depth X of the target 31 extending into the retarding body 14.
  • the order, the 4th order, and the 10th order slow speed body are compared and analyzed by the simulation experiment.
  • Table 2 Superheated neutron flux, fast neutron flux and superheat neutron forward direction when the first retarding body is stepless, 1st order 2nd order, 3rd order, 4th order, 10th order retarding body Sexual reference value
  • the first retarding body 140 has no step (cylindrical slow-moving body) or multi-step retarding body has little effect on the superheat neutron, fast neutron intensity and neutron forwardness, but Compared with the stepless retarding body, the retarding body material required for manufacturing the multi-step retarding body is less, and considering the material cost and the manufacturing process cost, preferably, the first retarding body 140 is set to the third order or 4 Step slow speed body.
  • Table 3 Superheated neutron flux, fast neutron flux and superthermal neutron forward reference value filled with reflection compensation body and without filling reflection compensation body
  • the gap between the accommodating chamber 12 and the vacuum tube 30 filled with the reflection compensator 50 is increased by 7.33% to 7.46% compared to the non-filled reflection compensator 50. There is no significant change in neutron forwardness.
  • the retarding body 14 is set to an entire cylindrical shape as shown in FIG.
  • the retarding body is either a double-cone slowing body as shown in FIG. 4 or a retarding body composed of a cone-shaped retarding body and a cylindrical retarding body or a multi-step retarding body and a cone
  • the gap-filling reflection compensator 50 between the accommodating chamber 12 and the vacuum tube 30 can increase the intensity of the super-heat neutron to varying degrees, and the forward tropism of the neutron is not obvious. Impact.
  • the left end of the beam shaping body 10 of the present application i.e., the end of the charged particle beam inlet, is provided with a neutron beam and gamma ray from the beam shaping body 10 formed at the target 31.
  • the shield 40 overflowing from the left end surface.
  • the first retarding body 140 is respectively a stepless, second-order, third-order, fourth-order, and ten-order slow-speed body, the shield 40 and/or the reflection compensator 50 are respectively disposed or the shield 40 and the shield 40 are not provided.
  • the reference value data is used to analyze the neutron at the left end of the beam shaping body 10, the gamma ray intensity, and the epithermal neutrons and fast neutrons at the beam exit 18 of the beam shaping body 10 by the shield 40 and the reflection compensating body 50.
  • the units of neutrons, gamma rays, superheated neutrons, and fast neutrons are all: n/cm 2 /sec.
  • Table 4 Neutron, gamma ray intensity at the left end of the beam shaping body and the superthermal neutron and fast neutron intensity at the beam exit of the beam shaping body and the superheat neutron forward reference value
  • the addition of the shield 40 can significantly reduce the intensity of the gamma ray and the neutron beam behind the beam shaping body 10, and the superheated neutron and fast neutron intensity of the shield 40 at the beam exit 18.
  • the effect is not significant, and increasing the reflection compensation body 50 can significantly increase the intensity of the epithermal neutron at the beam exit 18.
  • the tapered slow-moving body is a slow-acting body composed of a cone-shaped retarding body and a cylindrical retarding body, or a slow-moving body composed of a multi-step retarding body and a cone-shaped retarding body.
  • the gap filling reflection compensation body 50 between the accommodating chamber 12 and the vacuum tube 30 and the shielding body 40 disposed at the left end of the beam shaping body 10 can increase the intensity of the superthermal neutrons and reduce the gamma ray and the rear of the beam shaping body 10 to varying degrees. The intensity of the neutron beam has no significant effect on the forwardness of the neutron.
  • the depth X of the target 31 extending into the retarding body 14 is changed, that is, the dimension of the first retarding body 140 in the direction of the neutron beam axis X1 is changed.
  • Table 5 Superheated neutron flux, fast neutron flux and neutron forward reference value when the depth of the target into the slow velocity body is 5, 10, 15, 20CM respectively
  • the tapered slow-moving body is either a slow-moving body composed of a cone-shaped retarding body and a cylindrical retarding body or a slow-moving body composed of a multi-step retarding body and a cone-shaped retarding body.
  • Table 6 shows the yield of superheated neutrons (n/cm 2 mA) when filling air, aluminum alloy and lead alloy respectively under the aperture of different accommodating chambers:
  • Table 7 shows the amount of fast neutron contamination (Gy-cm2/n) when air, aluminum alloy, and lead alloy are filled separately at the aperture of different chambers:
  • Table 8 shows the irradiation time (minutes) required for the irradiated body when filled with air, aluminum alloy, and lead alloy under the apertures of different housing chambers:
  • the neutron capture treatment system disclosed herein is not limited to the contents described in the above embodiments and the structures represented in the drawings.
  • the retarding body may be provided as a tapered or polygonal prism
  • the cooling device may be provided in plurality
  • the receiving duct may have a plurality of and the like.
  • Obvious modifications, substitutions, or alterations of the materials, shapes, and positions of the components in the present application are within the scope of the present disclosure.

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Abstract

本申请提供一种中子捕获治疗系统，其包括射束整形体、设置于射束整形体内的真空管，射束整形体包括射束入口、容纳真空管的容纳腔、邻接于容纳腔端部的缓速体、包围在缓速体外的反射体、设置在射束整形体内的辐射屏蔽和射束出口，真空管端部设有靶材，靶材与自射束入口入射的带电粒子束发生核反应以产生中子，中子形成中子射束，中子射束自射束出口射出并限定一根中子射束轴线，缓速体将自靶材产生的中子减速至超热中子能区，反射体将偏离的中子导回至缓速体，辐射屏蔽用于屏蔽渗漏的中子和光子，缓速体至少包括两个外直径不同的圆柱体状缓速体，缓速体具有靠近射束入口的第一端部和靠近射束出口的第二端部，靶材容纳在第一端部和第二端部之间。

Description

中子捕获治疗系统 技术领域
本发明涉及一种放射性射线辐照系统，尤其涉及一种中子捕获治疗系统。
背景技术
随着原子科学的发展，例如钴六十、直线加速器、电子射束等放射线治疗已成为癌症治疗的主要手段之一。然而传统光子或电子治疗受到放射线本身物理条件的限制，在杀死肿瘤细胞的同时，也会对射束途径上大量的正常组织造成伤害；另外由于肿瘤细胞对放射线敏感程度的不同，传统放射治疗对于较具抗辐射性的恶性肿瘤(如：多行性胶质母细胞瘤(glioblastoma multiforme)、黑色素细胞瘤(melanoma))的治疗成效往往不佳。
为了减少肿瘤周边正常组织的辐射伤害，化学治疗(chemotherapy)中的标靶治疗概念便被应用于放射线治疗中；而针对高抗辐射性的肿瘤细胞，目前也积极发展具有高相对生物效应(relative biological effectiveness，RBE)的辐射源，如质子治疗、重粒子治疗、中子捕获治疗等。其中，中子捕获治疗便是结合上述两种概念，如硼中子捕获治疗，借由含硼药物在肿瘤细胞的特异性集聚，配合精准的中子射束调控，提供比传统放射线更好的癌症治疗选择。
因硼中子捕获治疗的成效取决于肿瘤细胞位置含硼药物浓度和热中子数量，故又被称为二元放射线癌症治疗(binary cancer therapy)；由此可知，除了含硼药物的开发，中子射源通量与品质的改善在硼中子捕获治疗的研究中占有重要角色。
此外，放射线治疗过程中会产生各种放射线，如硼中子捕获治疗过程产生低能至高能的中子、光子，这些放射线可能会对人体正常组织造成不同程度的损伤。因此在放射线治疗领域，如何在达到有效治疗的同时减少对外界环境、医务人员或患者正常组织的辐射污染是一个极为重要的课题。
因此，有必要提出一种新的技术方案以解决上述问题。
发明内容
为了解决上述问题，本申请的一个实施例提供一种中子捕获治疗系统，中子捕获治疗系统包括射束整形体、设置于射束整形体内的真空管，射束整形体包括射束入口、容纳真空管的容纳腔、邻接于容纳腔端部的缓速体、包围在缓速体外的反射体、设置在射束整形体内的辐射屏蔽和射束出口，真空管端部设有靶材，靶材与自射束入口入射的带电粒子束发生核反应以产生中子，中子形成中子射束，中子射束自射束出口射出并限定一根中子射束轴线，缓速体将自靶材产生的中子减速至超热中子能区，反射体将偏离的中子导回至缓速体以提高超热中子射束强度，辐射屏蔽用于屏蔽渗漏的中子和光子以减少非照射区的正常组织剂量，缓 速体至少包括两个外直径不同的圆柱体状缓速体，缓速体具有靠近射束入口的第一端部和靠近射束出口的第二端部，靶材容纳在第一端部和第二端部之间。
与现有技术相比，本实施例记载的技术方案具有以下有益效果：缓速体包括两个外直径不同的圆柱体状缓速体，且靶材容纳在缓速体内，能够降低材料成本且大大降低快中子的强度，改善中子射束品质。
进一步地，缓速体包括靠近射束入口的第一缓速体和与第一缓速体紧密贴合且靠近射束出口的第二缓速体，第一缓速体至少包括两个外直径不同的圆柱体状缓速体，射束入口、缓速体和射束出口均沿着中子射束轴线延伸，靶材到射束出口的距离小于第一端部到射束出口的距离。
优选地，第一缓速体包括三个外直径不同的圆柱体状缓速体，第一缓速体包括靠近射束入口的第一缓速部、与第一缓速部紧密贴合的第二缓速部及与第二缓速部紧密贴合的第三缓速部，第一、第二、第三缓速部沿中子射束轴线方向依次排列，第一、第二、第三缓速部与第二缓速体的外直径分别为第一、第二、第三、第四外直径，第一外直径小于第二外直径，第二外直径小于第三外直径，第三外直径等于第四外直径。
进一步地，第一缓速部具有靠近射束入口的第一前端面、靠近射束出口的第一后端面及第一外圆周面；第二缓速部具有与第一后端面紧密贴合的第二前端面、靠近射束出口的第二后端面及第二外圆周面；第三缓速部具有与第二后端面紧密贴合的第三前端面、靠近射束出口的第三后端面及第三外圆周面；第二缓速体具有与第三后端面紧密贴合的第四前端面、靠近射束出口的第四后端面及第四外圆周面，第一、第二、第三、第四前端面及第一、第二、第三、第四后端面之间相互平行且均与中子射束轴线垂直，穿过中子射束轴线的切面与第一外圆周面的交线与第二前端面垂直，穿过中子射束轴线的切面与第二外圆周面的交线与第三前端面垂直。
进一步地，在穿过中子射束轴线的切面内，第一前端面与第一外圆周面相交得到第一交点，第二前端面与第二外圆周面相交得到第二交点，第三前端面与第三外圆周面相交得到第三交点，第一、第二、第三交点位于同一条直线上。
优选地，容纳腔与真空管之间填充反射补偿体，反射补偿体为铅或Al或铁氟龙或C。
优选地，第一端部沿着中子射束轴线往射束入口的方向突出于靶材，第二端部沿着中子射束轴线往射束出口的方向突出于靶材。
进一步地，反射体在中子射束轴线的两侧均凸出缓速体，容纳腔包括由反射体围设而成的的反射体容纳腔及自反射体容纳腔延伸由缓速体围设而成的缓速体容纳腔，真空管包括容纳在反射体容纳腔内的延伸段及自延伸段延伸并容纳在缓速体容纳腔内的嵌入段，靶材设于 嵌入段的端部。
进一步地，中子捕获治疗系统还包括至少一个冷却装置，射束整形体内设有至少一个容纳冷却装置的容纳管道，冷却装置与容纳管道的内壁之间填充有铅合金或铝合金。
进一步地，中子捕获治疗系统还包括设于射束入口并与射束整形体紧密贴合设置的屏蔽体。
本申请实施例中所述的“锥体”或“锥状体”是指沿着图示方向的一侧到另一侧其外轮廓的整体趋势逐渐变小的结构，外轮廓的整个表面可以是圆滑过渡的，也可以是非圆滑过渡的，如在圆锥状体表面做了很多凸起和凹槽。
附图说明
图1是本申请实施例一中的中子捕获治疗系统的示意图，其中，冷却装置的第二冷却部和第三冷却部与中子射束轴线平行；
图2是本申请实施例一中的未填充反射补偿体和反射补偿物的中子捕获治疗系统的示意图；
图3是本申请实施例一中的沿图1中垂直于中子射束轴线并穿过第二缓速部的中子捕获治疗系统的剖视图；
图4是本申请实施例二中的中子捕获治疗系统的示意图，其中，缓速体设置成双锥状缓速体；
图5是本申请实施例一、二中的中子捕获治疗系统的冷却装置的局部放大示意图；
图6是本申请实施例三中的中子捕获治疗系统的示意图，其中，冷却装置的第二冷却部和第三冷却部与中子射束轴线垂直；
图7是本申请实施例中的中子捕获治疗系统中的靶材结构示意图；
图8是本申请实施例四中去除冷却装置且靶材未伸入缓速体的中子捕获治疗系统的示意图；
图9是本申请实施例五中去除冷却装置且第一缓速体为无阶缓速体的中子捕获治疗系统的示意图；
图10是本申请实施例六中去除冷却装置且第一缓速体为2阶缓速体的中子捕获治疗系统的示意图；
图11是本申请实施例七中去除冷却装置且第一缓速体为4阶缓速体的中子捕获治疗系统的示意图；
图12是本申请实施例八中去除冷却装置且第一缓速体为10阶缓速体的中子捕获治疗系统的示意图；
具体实施方式
中子捕获治疗作为一种有效的治疗癌症的手段近年来的应用逐渐增加，其中以硼中子捕 获治疗最为常见，供应硼中子捕获治疗的中子可以由核反应堆或加速器供应。本申请的实施例以加速器硼中子捕获治疗为例，加速器硼中子捕获治疗的基本组件通常包括用于对带电粒子(如质子、氘核等)进行加速的加速器、中子产生部与热移除系统以及射束整形体。其中加速带电粒子与金属中子产生部作用产生中子，依据所需的中子产率与能量、可提供的加速带电粒子能量与电流大小、金属中子产生部的物化性等特性来挑选合适的核反应。常被讨论的核反应有 7Li(p，n) 7Be及 9Be(p，n) 9B，这两种反应皆为吸热反应，两种核反应的能量阀值分别为1.881MeV和2.055MeV。由于硼中子捕获治疗的理想中子源为keV能量等级的超热中子，理论上若使用能量仅稍高于阀值的质子轰击金属锂中子产生部，可产生相对低能的中子，不须太多的缓速处理便可用于临床，然而锂金属(Li)和铍金属(Be)两种中子产生部与阀值能量的质子作用截面不高，为产生足够大的中子通量，通常选用较高能量的质子来引发核反应。
理想的靶材应具备高中子产率、产生的中子能量分布接近超热中子能区(将在下文详细描述)、无太多强穿辐射产生、安全便宜易于操作且耐高温等特性，但实际上并无法找到符合所有要求的核反应。本申请的实施例中采用锂金属制成的靶材。但是本领域技术人员熟知的，靶材的材料也可以由其他除了上述谈论到的金属材料之外的金属材料制成。
针对热移除系统的要求则根据选择的核反应而异，如 7Li(p，n) 7Be因金属靶材(锂金属)的熔点及热导系数差，对热移除系统的要求便较 9Be(p，n) 9B高。本申请的实施例中采用 7Li(p，n) 7Be的核反应。由此可知，受到高能量等级的加速带电粒子束照射的靶材的温度必然会大幅上升，从而影响靶材的使用寿命。
无论硼中子捕获治疗的中子源来自核反应堆或加速器带电粒子与靶材的核反应，产生的皆为混合辐射场，即射束包含了低能至高能的中子、光子。对于深部肿瘤的硼中子捕获治疗，除了超热中子外，其余的辐射线含量越多，造成正常组织非选择性剂量沉积的比例越大，因此这些会造成不必要剂量的辐射应尽量降低。除了空气射束品质因素，为更了解中子在人体中造成的剂量分布，本申请的实施例中使用人体头部组织假体进行剂量计算，并以假体射束品质因素来作为中子射束的设计参考，将在下文详细描述。
国际原子能机构(IAEA)针对临床硼中子捕获治疗用的中子源，给定了五项空气射束品质因素建议，此五项建议可用于比较不同中子源的优劣，并供以作为挑选中子产生途径、设计射束整形体时的参考依据。这五项建议分别如下：
超热中子射束通量Epithermal neutron flux＞1x 10 9n/cm 2s
快中子污染Fast neutron contamination＜2x 10 -13Gy-cm 2/n
光子污染Photon contamination＜2x 10 -13Gy-cm 2/n
热中子与超热中子通量比值thermal to epithermal neutron flux ratio＜0.05
中子流与通量比值epithermal neutron current to flux ratio＞0.7
注：超热中子能区在0.5eV到40keV之间，热中子能区小于0.5eV，快中子能区大于40keV。
1、超热中子射束通量：
中子射束通量和肿瘤中含硼药物浓度共同决定了临床治疗时间。若肿瘤含硼药物浓度够高，对于中子射束通量的要求便可降低；反之，若肿瘤中含硼药物浓度低，则需高通量超热中子来给予肿瘤足够的剂量。IAEA对于超热中子射束通量的要求为每秒每平方厘米的超热中子个数大于10 9，此通量下的中子射束对于目前的含硼药物而言可大致控制治疗时间在一小时内，短治疗时间除了对病人定位和舒适度有优势外，也可较有效利用含硼药物在肿瘤内有限的滞留时间。
2、快中子污染：
由于快中子会造成不必要的正常组织剂量，因此视之为污染，此剂量大小和中子能量呈正相关，因此在中子射束设计上应尽量减少快中子的含量。快中子污染定义为单位超热中子通量伴随的快中子剂量，IAEA对快中子污染的建议为小于2x 10 -13Gy-cm 2/n。
3、光子污染(γ射线污染)：
γ射线属于强穿辐射，会非选择性地造成射束路径上所有组织的剂量沉积，因此降低γ射线含量也是中子束设计的必要要求，γ射线污染定义为单位超热中子通量伴随的γ射线剂量，IAEA对γ射线污染的建议为小于2x 10 -13Gy-cm 2/n。
4、热中子与超热中子通量比值：
由于热中子衰减速度快、穿透能力差，进入人体后大部分能量沉积在皮肤组织，除黑色素细胞瘤等表皮肿瘤需用热中子作为硼中子捕获治疗的中子源外，针对脑瘤等深层肿瘤应降低热中子含量。IAEA对热中子与超热中子通量比值建议为小于0.05。
5、中子电流与通量比值：
中子电流与通量比值代表了射束的方向性，比值越大表示中子射束前向性佳，高前向性的中子束可减少因中子发散造成的周围正常组织剂量，另外也提高了可治疗深度及摆位姿势弹性。IAEA对中子电流与通量比值建议为大于0.7。
为了使中子捕获治疗系统的射束整形体在降低制造成本的同时，能够获得较好的中子射束品质，参照图1所示，本申请实施例一提供一种中子捕获治疗系统1，中子捕获治疗系统1 包括射束整形体10、设于射束整形体10内的冷却装置20、真空管30及设于射束整形体10外并紧密贴合射束整形体10设置的屏蔽体40。
如图1和图2所示，射束整形体10包括射束入口11、用于容纳真空管30的容纳腔12、用于容纳冷却装置20的容纳管道13、邻接于容纳腔12端部的缓速体14、包围缓速体14的反射体15、与缓速体14邻接的热中子吸收体16、设置在射束整形体10内的辐射屏蔽17和射束出口18。真空管30的端部设有靶材31，靶材31与自射束入口11入射并穿过真空管30的带电粒子束发生核反应以产生中子，中子形成中子射束，中子射束自射束出口18射出并限定一根与真空管30的中心轴线重合的中子射束轴线X1。缓速体14将自靶材31产生的中子减速至超热中子能区，反射体15将偏离中子射束轴线X1的中子导回至缓速体14以提高超热中子射束强度。反射体15在中子射束轴线X1的两侧均凸出缓速体14。热中子吸收体16用于吸收热中子以避免治疗时与浅层正常组织造成过多剂量。辐射屏蔽17用于屏蔽渗漏的中子和光子以减少非照射区的正常组织剂量。
加速器中子捕获治疗系统通过加速器将带电粒子束加速，作为一种优选实施例，靶材31由锂金属制成，具体地，由 7Li含量为98％、 6Li含量为2％的锂金属制成，带电粒子束加速至足以克服靶材原子核库伦斥力的能量，与靶材31发生 7Li(p，n) 7Be核反应以产生中子，射束整形体10能将中子缓速至超热中子能区，并降低热中子及快中子含量。缓速体14由具有快中子作用截面大、超热中子作用截面小的材料制成，反射体15由具有中子反射能力强的材料制成，热中子吸收体16由与热中子作用截面大的材料制成。作为一种优选实施例，缓速体14由MgF 2和占MgF 2的重量百分比为4.6％的LiF混合制成，反射体15由Pb制成，热中子吸收体16由 6Li制成。辐射屏蔽17包括光子屏蔽171和中子屏蔽172，作为一种优选实施例，辐射屏蔽17包括由铅(Pb)制成的光子屏蔽171和由聚乙烯(PE)制成的中子屏蔽172。如图7所示，靶材31包括锂靶层311和位于锂靶层311一侧用于防止锂靶层311氧化的抗氧化层312。靶材31的抗氧化层312由Al或者不锈钢制成。
如图1-2所示，缓速体14包括靠近射束入口11的第一缓速体140及与第一缓速体140紧密贴合并靠近射束出口18的第二缓速体144，缓速体14具有靠近射束入口11的第一端部146、靠近射束出口18的第二端部148及位于第一端部146与第二端部148之间的第三端部147，第三端部147位于第一缓速体140和第二缓速体144之间。射束入口11、缓速体14和射束出口18均沿着中子射束轴线X1延伸，靶材31到射束出口18的距离小于第一端部146到射束出口18的距离，换句话说，第一端部146沿着中子射束轴线X往射束入口11的方向突出于靶材31，第二端部148沿着中子射束轴线X1往射束出口18的方向突出于靶材31。第一缓速体140由至少2个外直径不同、内直径相同的中空的圆柱体状缓速体组成。参照图1-2、图6及图8所示，在实施例一、实施例三、实施例四中，第一缓速体140由3个外直径 不同、内直径相同的中空的圆柱体状缓速体组成，第一缓速体140及第二缓速体144由从对应尺寸的模具中成型的若干片缓速体通过抛光、打磨等工艺处理之后层叠拼接而成。具体地，第一缓速体140包括靠近射束入口11的第一缓速部141、位于第一缓速部141右侧并与第一缓速部141紧密贴合的第二缓速部142及位于第二缓速部142右侧并与第二缓速部142紧密贴合的第三缓速部143组成，也就是说，第一、第二、第三缓速部141、142、143沿中子射束轴线X1方向依次排列。第一、第二、第三缓速部141、142、143与第二缓速体144的外直径分别为第一、第二、第三、第四外直径，第一外直径小于第二外直径，第二外直径小于第三外直径，第三外直径等于第四外直径，第一、第二、第三缓速部141、142、143的内直径相等。第一、第二、第三缓速部141、142、143的中心轴线与第二缓速体144的中心线重合，该中心轴线与中子射束轴线X1亦重合。第一缓速部141具有位于左侧的第一前端面1411、位于右侧的第一后端面1412、第一外圆周面1413及第一内圆周面1414；第二缓速部142具有位于左侧的第二前端面1421、位于右侧的第二后端面1422、第二外圆周面1423及第二内圆周面1424；第三缓速部143具有位于左侧的第三前端面1431、位于右侧的第三后端面1432、第三外圆周面1433及第三内圆周面1434；第二缓速体144具有位于左侧的第四前端面1441、位于右侧的第四后端面1442及第四外圆周面1443。第一、第二、第三、第四前端面1411、1421、1431、1441及第一、第二、第三、第四后端面1412、1422、1432、1442之间相互平行且均与中子射束轴线X1垂直，第一缓速部141的第一后端面1412与第二缓速部142的第二前端面1421紧密贴合，第二缓速部142的第二后端面1422与第三缓速部143的第三前端面1431紧密贴合，第三缓速部143的第三后端面1432与第二缓速体144的第四前端面1441紧密贴合。穿过中子射束轴线X1的切面与第一外圆周面1413的交线与第二前端面1421垂直，穿过中子射束轴线X1的切面与第二外圆周面1423的交线与第三前端面1431垂直，第三缓速部的第三外圆周面1433与第二缓速体144的第四外圆周面1443之间平滑过渡。如图2所示，在穿过中子射束轴线X1的切面内，第一缓速部141的第一前端面1411与第一外圆周面1413相交得到第一交点1410，第二缓速部142的第二前端面1421与第二外圆周面1423相交得到第二交点1420，第三缓速部143的第三前端面1431与第三外圆周面1433相交得到第三交点1430，第一、第二、第三交点1410、1420、1430位于同一条直线X2上，该直线X2与中子射束轴线X1之间的夹角小于90度。反射体15具有包围缓速体14的内表面150，该内表面150与缓速体14的第一前端面1411、第一外圆周面1413、第二前端面1421、第二外圆周面1423、第三前端面1431、第三外圆周面1433、第四后端面1442及第四外圆周面1443紧密贴合。
如1-2、图6及图8所示，在实施例一、实施例三、实施例四中，第一缓速体140由3 个外直径不同、内直径相同的同心的中空的圆柱体状缓速体组成，从垂直于中子射束轴线X1的方向观察，第一、第二、第三缓速部141、142、143的外轮廓组合在一起呈台阶状，由此，将第一缓速体140命名为3阶缓速体。如图10-12所示，在实施例六到实施例八中，第一缓速体140由2个、4个、10个外直径不同、内直径相同的中空的圆柱体状缓速体组成，即第一缓速体140可以是2阶、4阶、10阶缓速体，在其他实施方式中，第一缓速体140还可以由其他数目个外直径不同、内直径相同的中空的圆柱体状缓速体组成，例如12个、15等等。在其他实施方式中，亦可将第二缓速体144设置成呈台阶状的缓速体；还可以用多边形棱柱体代替圆柱体成型缓速体；另外，第一、第二、第三交点1410、1420、1430可以不在同一条直线上，可以位于一条弧线上；另外，可以根据实际需要，将组成第一缓速体140的缓速部设置为部分非中空结构；第一缓速体140的各个缓速部的中心轴线和第二缓速体14的中心轴线可以相互不重合。
通常，缓速体由从对应尺寸的模具中成型的若干片缓速体通过抛光、打磨等工艺处理之后层叠拼接而成，从磨具中成型的缓速体为圆盘状，当缓速体设计成一整个圆柱体状或是锥体状的时候，所消耗的缓速体材料的体积为缓速体在中子射束轴线X1方向的尺寸与圆盘的底面积的乘积，需要说明的是，锥体状缓速体是由圆柱状缓速体打磨而成，也就是说，缓速体设计成圆柱体状或是锥体状所需要的材料的体积是相同的。而在本申请中，将第一缓速体140设计成台阶状缓速体，在缓速体在中子射束轴线X1方向上的尺寸和缓速体的最大直径不变的前提下，因组成各阶缓速的圆盘状缓速体的底面积是逐渐增大的，则本申请中将缓速体设计为台阶状缓速体所需的缓速体材料小于将缓速体设计成一整个圆柱体状或是锥体状缓速体所需的材料。由此可以看出，本申请台阶状缓速体能够大大减少制造缓速体的材料，从而降低制造成本。
参照图2所示，容纳腔12是由反射体15及缓速体14的第一缓速体140围设而成的圆柱形腔。容纳腔12包括由反射体15围设而成的反射体容纳腔121及自反射体容纳腔121延伸由缓速体14的第一缓速体140围设而成的缓速体容纳腔122，即缓速体容纳腔122由第一、第二、第三缓速部141、142、143的第一、第二、第三内圆周面1414、1424、1434围设而成。真空管30包括被反射体15包围的延伸段32及自延伸段32延伸嵌入缓速体14的嵌入段34，延伸段32容纳在反射体容纳腔121内，嵌入段34容纳在缓速体容纳腔122内。靶材31设于真空管30的嵌入段34的端部，该端部与第一缓速体140的第三后端面1432平齐。在实施例一至三及实施例五至八中，真空管30部分嵌设于缓速体14中，即靶材31设置于缓速体14内。将靶材31伸入缓速体14的深度标记为X，X的值等于在中子射束轴线X1的方向上缓速体容纳腔122的尺寸，即在中子射束轴线X1的方向上第一缓速体140的尺寸。
在其他实施方式中，靶材31伸入缓速体14的深度X可以小于或大于第一缓速体140在中子射束轴线X1方向上的尺寸，即靶材31可以设置成在中子射束轴线X1方向上延伸未超过第一缓速体140或延伸超过第一缓速体140而延伸进入第二缓速体144，相应地，当靶材31设置成在中子射束轴线X1方向上延伸未超过第一缓速体140时，第一缓速体140设置成部分非中空结构，当靶材31设置成在中子射束轴线X1方向上延伸超过第一缓速体140而延伸进入第二缓速体144时，第一缓速体140为中空结构，第二缓速体144为部分中空结构。
结合图1、图2及图3所示，容纳腔12与真空管30之间存在间隙，在该间隙中填充有反射补偿体50，反射补偿体50是能够吸收或反射中子的Pb或Al或铁氟龙(Teflon)或C。反射补偿体50能够将反射或散射进入该间隙内的中子反射到缓速体14或反射体15内，从而增加超热中子的强度进而减少被照射体需要被照射的时间。另一方面，避免中子渗漏到射束整形体10外部对中子捕获治疗系统的器械造成不良影响、提高辐射安全性。
如图1及图2所示，容纳管道13包括沿中子射束轴线X1方向延伸并位于容纳腔12两侧且间隔180°设置的第二、第三容纳管道132、133及设置在与中子射束轴线X1垂直的平面内并位于靶材31与缓速体14之间的第一容纳管道131。第二、第三容纳管道132、133在中子射束轴线X1的方向上延伸超过容纳腔12且分别与第一容纳管道131连通。也就是说，第一容纳管道131位于容纳腔12的端部且位于靶材31与缓速体14之间，第二容纳管道132和第三容纳管道133分别位于容纳腔12的两侧而分别与第一容纳管道131连通，从而使得整个容纳管道30呈“匚”型结构设置。结合图2所示，第二、第三容纳管道132、133分别包括位于反射体容纳腔121外侧的第二、第三反射体容纳管道1321、1331及分别自第二、第三反射体容纳管道1321、1331延伸而位于缓速体容纳腔122外侧的第二、第三缓速部容纳管道1322、1332。本实施方式中，第二、第三容纳管道132、133沿中子射束轴线X1方向延伸并平行于中子射束轴线X1，即第二、第三容纳管道132、133与中子射束轴线X1之间的夹角为0°。
在实施例一、二中，第二、第三容纳管道132、133与容纳腔12不连通，即第二、第三容纳管道132、133与容纳腔12之间被反射体15和缓速体14隔开。在其他实施方式中，第二、第三容纳管道132、133与容纳腔12可以连通，即容纳在容纳腔12内的真空管30的外表面部分暴露在第二、第三容纳管道132、133内，综上，第二、第三容纳管道132、133位于容纳腔12的内壁之外。在本申请实施方式中，第二、第三容纳管道132、133设置成沿真空管30的轴线方向延伸的圆弧形管道，在其他实施方式中，亦可用方形、三角形或其他多边形的管道代替。在本申请实施方式中，第二、第三容纳管道132、133为在容纳腔12的圆周方向上间隔开相互独立的两个容纳管道，在其他实施方式中，第二、第三容纳管道132、133 在容纳腔12的圆周方向上连通，即由一个环绕容纳腔12的容纳管道代替。
如图5所示，冷却装置20包括沿竖直方向布置并位于靶材31前方用于冷却靶材31的第一冷却部21、沿中子射束轴线X1方向延伸而位于真空管30两侧并平行于中子射束轴线X1的第二冷却部22和第三冷却部23，第一冷却部21连接在第二、第三冷却部22、23之间。第一冷却部21被容纳在沿垂直于中子射束轴线X1方向布置的第一容纳管道131内，第二、第三冷却部22、23分别被容纳在沿中子射束轴线X1的方向布置的第二、第三容纳管道132、133内。第二冷却部22向第一冷却部21输入冷却介质，第三冷却部23将第一冷却部21中的冷却介质输出。第一冷却部21位于靶材31和缓速体14之间，第一冷却部21的一侧与靶材31直接接触，另一侧与缓速体14接触。第二冷却部22和第三冷却部23分别包括位于反射体容纳腔121外侧的第一、第二冷却段221、231及自第一、第二冷却段221、231延伸并位于缓速体容纳腔122外侧的第三、第四冷却段222、232。第三、第四冷却段222、232分别与第一冷却部21连通。也就是说，第一冷却部21位于真空管30的嵌入段121的端部而位于靶材31一侧并与靶材31直接接触，第二冷却部22和第三冷却部23分别位于容纳在容纳腔12内的真空管30的上下两侧而分别与第一冷却部21连通，从而使得整个冷却装置20呈“匚”型结构设置。本实施方式中，第一冷却部21与靶材31平面接触，第二冷却部22和第三冷却部23都是由铜制成的管状结构，且第二冷却部22和第三冷却部23沿中子射束轴线X1的方向延伸并平行于中子射束轴线X1，即第二冷却部22和第三冷却部23与中子射束轴线X1之间的夹角为0°。
第一冷却部21包括第一接触部211、第二接触部212及位于第一接触部211和第二接触部212之间的供冷却介质通过的冷却槽213。第一接触部211与靶材31直接接触，第二接触部212与缓速体14可以是直接接触也可以通过空气间接接触。冷却槽213具有与第二冷却部22连通的输入槽214及与第三冷却部23连通的输出槽215。第一接触部211由导热材料制成。输入槽214的上边沿位于第二冷却部22的上边沿的上方，输出槽215的下边沿位于第三冷却部23的下边沿的下方。这样设置的好处是，冷却装置20能够更加顺畅地将冷却水输入冷却槽213中并且较及时地对靶材31进行冷却，而受热后的冷却水也能够较为顺畅的从冷却槽213中输出，同时，还能够在一定程度上降低冷却槽213中冷却水的水压。
第一接触部211由导热材料(如Cu、Fe、Al等导热性能好的材料)或既能导热又能抑制发泡的材料制成，第二接触部212由抑制发泡的材料制成，抑制发泡的材料或既能导热又能抑制发泡的材料由Fe、Ta或V的任一种制成。靶材31受到高能量等级的加速照射温度升高发热，第一接触部211将热量导出，并通过流通在冷却槽213中的冷却介质将热量带出，从而对靶材31进行冷却。在本实施方式中，冷却介质为水。
参照图2所示，屏蔽体40覆盖射束整形体10的左侧端面并与该端面紧密贴合，防止在 靶材31处形成的中子束和γ射线从射束整形体10左端面溢出。屏蔽体40由Pb和PE组成，具体地，屏蔽体40由至少两层Pb和至少一层PE组成。在本实施例中，屏蔽体40包括与射束整形体10的左端面紧密贴合的第一Pb层41、与第一Pb层41紧密贴合的PE层42及覆盖PE层42且与PE层42紧密贴合的第二Pb层43。Pb能够吸收从射束整形体10溢出的γ射线和将从射束整形体10溢出的中子反射回到缓速体14以提高超热中子射束强度。
参照图1-2、图6、图8及图10-12所示，在实施例一、实施例三、实施例四及实施例六-八中，缓速体14部分由多阶缓速体组成，在实施例五中，如图9所示，缓速体14由一整个圆柱状缓速体组成，在其他实施方式中，缓速体14也可以由一个锥体壮缓速体和一个圆柱状缓速体组成，亦可由如图4所示实施二中的两个锥状体缓速体组成。在实施例二中，缓速体14′由两个反向的锥状体组成，在本申请中，将实施例二中的缓速体14′称为双锥状缓速体。参照图4，缓速体14′具有第一端部141′、第二端部142′和位于第一端部141′和第二端部142′之间的第三端部143′。第一、第二、第三端部141′、142′、143′的横截面为圆形，且第一端部141′与第二端部14′2的直径小于第三端部143′的直径。第一端部141′和第三端部143′之间形成第一个锥状体146′，第三端部143′和第二端部142′之间形成第二个锥状体148′。靶材31容纳在第一个锥状体142′内。
在实施例二中，第二、第三容纳管道132、133及第二、第三冷却部22、23与中子射束轴线X1之间的夹角为0°。在其他实施方式中，第二、第三容纳管道132、133及第二、第三冷却部22、23与中子射束轴线X1之间的夹角还可以是其他大于0°小于等于180°的任意夹角，例如图6所示，第二、第三容纳管道132′、133′及第二、第三冷却部22′、23′与中子射束轴线X1之间的夹角为90°。
如图6所示，其揭示本申请实施例三中的中子捕获治疗系统1″，其中，冷却装置20′的第二冷却部22′和第三冷却部23′与中子射束轴线X1垂直，即冷却装置20′设置成“I”型结构对嵌入式的真空管30中的靶材31进行冷却。“I”型冷却装置20′中的第一冷却部21′第与匚型冷却装置20的第一冷却部21设置相同，不同之处在于，“I”型冷却装置20′的第二冷却部22′和第三冷却部23′与第一冷却部21′位于与中子射束轴线X1′垂直的同一平面内，且第二冷却部22′和第三冷却部23′分别沿与中子射束轴线X1垂直的方向穿设出缓速体14′，即第二冷却部22′和第三冷却部23′与中子射束轴线X1之间的夹角为90°，使得整个冷却装置呈矩形设置，也就是上述“I”型结构。继续参照图6，相应的，容纳管道30′亦设为“I”型结构，“I”型容纳管道30′中的第一容纳管道131′与匚型冷却管道30的第一容纳管道131设置相同，不同之处在于，“I”型容纳管道30′的第二容纳管道132′和第三容纳管道133′与第一容纳管道131′位于与中子射束轴线X1垂直的同一平面内，且第二容纳管道132′和第三容纳管道133′分别沿与中子射束轴线X1垂直的方向穿设出缓速体14′，即第二、第三容纳管道132′、133′与中子射束轴线X1之间的夹角为90°，使得整个容纳管道呈矩形设置，也就是上述“I”型结构。容易想到的是，在图4及图9所示的结构中，冷却装置20和容纳管道30亦可以设置成“I”型结构。
图8为图1或图6去除冷却装置20、20′且靶材31未伸入缓速体14的中子捕获治疗系统 1、1′的示意图，图8所揭示的中子捕获治疗系统1与图1或图6揭示的中子捕获治疗系统1、1″相比，仅是将靶材31设置在缓速体14外，即容纳真空管30的容纳腔12未延伸进入缓速体14而是仅由反射体15围设而成。缓速体14、反射体15、屏蔽体40、冷却装置20、20′、热中子吸收体16、辐射屏蔽17等的结构与图1或图6揭示的结构相同，相关描述请参照上文对相关结构的描述，在此不再赘述。
图9是本申请去除冷却装置20、20′且第一缓速体为无阶缓速体的中子捕获治疗系统1的示意图，图9所揭示的中子捕获治疗系统1与图1或图6揭示的中子捕获治疗系统1、1″相比，仅是将第一缓速体140由3阶缓速体替换为无阶缓速体，即第一缓速体140由一个外直径与圆柱体状缓速体144的外直径相等的中空的圆柱体状第二缓速体构成。反射体15、屏蔽体40、冷却装置20、20′、热中子吸收体16、辐射屏蔽17等的结构与图1或图6揭示的结构相同，相关描述请参照上文对相关结构的描述，在此不再赘述。
图10是本申请去除冷却装置20、20′且第一缓速体为无阶缓速体的中子捕获治疗系统1的示意图，图10所揭示的中子捕获治疗系统1与图1或图6揭示的中子捕获治疗系统1、1″相比，仅是将第一缓速体140由3阶缓速体替换为2阶缓速体，反射体15、屏蔽体40、冷却装置20、20′、热中子吸收体16、辐射屏蔽17等的结构与图1或图6揭示的结构相同，相关描述请参照上文对相关结构的描述，在此不再赘述。
图11是本申请去除冷却装置20、20′且第一缓速体为无阶缓速体的中子捕获治疗系统1的示意图，图11所揭示的中子捕获治疗系统1与图1或图6揭示的中子捕获治疗系统1、1″相比，仅是将第一缓速体140由3阶缓速体替换为4阶缓速体，反射体15、屏蔽体40、冷却装置20、20′、热中子吸收体16、辐射屏蔽17等的结构与图1或图6揭示的结构相同，相关描述请参照上文对相关结构的描述，在此不再赘述。
图12是本申请去除冷却装置20、20′且第一缓速体为无阶缓速体的中子捕获治疗系统1的示意图，图12所揭示的中子捕获治疗系统1与图1或图6揭示的中子捕获治疗系统1、1″相比，仅是将第一缓速体140由3阶缓速体替换为10阶缓速体，反射体15、屏蔽体40、冷却装置20、20′、热中子吸收体16、辐射屏蔽17等的结构与图1或图6揭示的结构相同，相关描述请参照上文对相关结构的描述，在此不再赘述。
参照图1、图2、图4及图6所示，第二、第三冷却部22、23；22′、23′分别与第二、第三容纳管道132、133；132′、133′的内壁之间存在间隙，该间隙内填充有反射补偿物80；80′，反射补偿物80；80′为铅合金或铝合金等能够吸收或反射中子的物质。反射补偿物80；80′能够将反射或散射进入该间隙内的中子反射到缓速体14或反射体15内，从而增加超热中子的产率进而减少被照射体需要被照射的时间。另一方面，避免中子渗漏到射束整形体10外部对中子捕获治疗系统的器械造成不良影响、提高辐射安全性。本申请实施例中，铅合金中铅的含量大于等于85％，铝合金中铝的含量大于等于85％。
下面通过模拟实验对本申请的相关结构中超热中子通量、快中子通量和超热中子前向性参照值、γ射线强度进行统计、分析，在本申请所有模拟实验中，带电粒子源能量为2.5MeV、 10mA，超热中子通量、快中子通量计数面位于射束整形体10的射束出口18处，射束出口18的直径是14CM，γ射线强度的计数面为射束整形体10左端面。
参照图1及图2所示，实施例一中的靶材31容纳在速体14内，参照图8所示，实施例四中的靶材31设置于缓速体14外，为了比较实施例一和实施例四中靶材31的设置位置对超热中子通量、快中子通量及中子前向性的影响，通过模拟实验得出表一的数据进行比较、分析。本申请中，缓速体14的厚度指缓速体14在中子射束轴线X1方向上的尺寸。
表一：靶材容纳在缓速体内和设置于缓速体外的超热中子通量、快中子通量和超热中子前向性参照值
Figure PCTCN2018100787-appb-000001
从表一可以看出，将靶材31容纳在缓速体14内和设置在缓速体14外相比，中子的前向性没有发生明显的改变，快中子的强度降低了12.52％，超热中子束强度仅降低1.83％，可见，将靶材31容纳在缓速体14的设置方式优于将靶材31设置于缓速体14外的设置方式。需要说明的是，超热中子前向性参照值越接近1，则超热中子前向性越好。
参照图1、图2所示，在实施例一中，第一缓速体140是3阶缓速体，参照图9-12所示，在实施例五到实施例八中，第一缓速体140分别设置为无阶、2阶、3阶、4阶、10阶缓速体，为了比较不同阶数的第一缓速体140对超热中子通量、快中子通量及中子前向性的影响，本申请在保持夹角θ及靶材31伸入缓速体14的深度X不变的前提下，将第一缓速体140分别设置为无阶、2阶、3阶、4阶、10阶缓速体，通过模拟实验得出表二的数据进行比较、分析。
表二：第一缓速体分别为无阶梯、1阶2阶、3阶、4阶、10阶缓速体时的超热中子通量、快中子通量和超热中子前向性参照值
Figure PCTCN2018100787-appb-000002
从表二数据可以看出，第一缓速体140无阶(圆柱状缓速体)或多阶缓速体对超热中子、快中子强度及中子前向性影响不大，但是相较于无阶缓速体，制造多阶缓速体所需的缓速体材料较少，综合考虑材料成本和制造工艺成本，优选地，将第一缓速体140设置为3阶或4阶缓速体。
参照图1-4、图8及图10-12所示，容纳腔12与真空管30之间存在间隙，在该间隙填充反射补偿体50。为了比较该间隙中填充反射补偿体50或不填充反射补偿体50对超热中子、快中子强度及超热中子前向性产生的影响，列出表三做详细比较、分析。
表三：填充反射补偿体和不填充反射补偿体的超热中子通量、快中子通量和超热中子前向性参照值
Figure PCTCN2018100787-appb-000003
从表3可以看出，容纳腔12与真空管30之间的间隙填充反射补偿体50与不填充反射补偿体50相比，超热中子束强度增加7.33％～7.46％。中子前向性没有明显改变。
本申请中仅列出针对将缓速体140部分设置为多阶缓速体做模拟实验得出的数据，但是 经研究得出，将缓速体14设置为图9所示的一整个圆柱状缓速体或设置为图4所示的双锥状缓速体或是由一个锥体状缓速体和一个圆柱状缓速体组成的缓速体或是由多阶缓速体和锥体状缓速体组成的缓速体时，在容纳腔12与真空管30之间的间隙填充反射补偿体50均能不同程度地增加超热中子的强度，且对中子的前向性没有明显的影响。
参照图1-2及图8-12本申请的射束整形体10的左端，即带电粒子束入口一端，设有防止在靶材31处形成的中子束和γ射线从射束整形体10左端面溢出的屏蔽体40。下面列出第一缓速体140分别为无阶、2阶、3阶、4阶、10阶缓速体时，分别设置屏蔽体40和/或反射补偿体50或未设置屏蔽体40和/或反射补偿体50时射束整形体10左端的中子、γ射线强度及射束整形体10的射束出口18处的超热中子、快中子的强度及超热中子前向性参照值数据，以分析屏蔽体40和反射补偿体50对射束整形体10左端的中子、γ射线强度及射束整形体10的射束出口18处的超热中子、快中子的强度及超热中子前向性的影响。其中中子、γ射线、超热中子、快中子的单位均为：n/cm 2/sec。
表四：射束整形体左端的中子、γ射线强度及射束整形体的射束出口处的超热中子、快中子的强度及超热中子前向性参照值
Figure PCTCN2018100787-appb-000004
从表四可以看出，增加屏蔽体40，能显著降低射束整形体10后方γ射线和中子束的强度，屏蔽体40对射束出口18处的超热中子和快中子强度的影响不显著，增加反射补偿体50能够显著提高射束出口18处的超热中子强度。
本申请中仅列出针对将缓速体140部分设置为无阶或多阶缓速体做模拟实验得出的数据，但是经研究得出，将缓速体14设置为图4所示的双锥状缓速体或是由一个锥体状缓速体和一 个圆柱状缓速体组成的缓速体或是由多阶缓速体和锥体状缓速体组成的缓速体时，在容纳腔12与真空管30之间的间隙填充反射补偿体50和在射束整形体10左端设置屏蔽体40均能不同程度地增加超热中子的强度和降低射束整形体10后方γ射线和中子束的强度，且对中子的前向性没有明显的影响。
下面通过实验模拟数据分析保持θ角不变的前提下，改变靶材31伸入缓速体14的深度X，即改变第一缓速体140沿中子射束轴线X1的方向上的尺寸，对超热中子通量、快中子通量及中子前向性的影响。
表五：靶材伸入缓速体的深度X分别为5、10、15、20CM时超热中子通量、快中子通量及中子前向性参照值
Figure PCTCN2018100787-appb-000005
从表五可以看出，随着靶材3伸入缓速体14的深度的增加，超热中子束强度略有下降(约2％)，快中子强度降低约6％，超热中子前向性无明显变化，超热中子与快中子通量比有所提升。
本申请中仅列出针对将缓速体140部分设置为无阶或多阶缓速体做模拟实验得出的数据，但是经研究得出，将缓速体14设置为图4所示的双锥状缓速体或是由一个锥体状缓速体和一个圆柱状缓速体组成的缓速体或是由多阶缓速体和锥体状缓速体组成的缓速体时，随着靶材3伸入缓速体14的深度的增加，超热中子束强度略有下降，快中子强度降低约，超热中子前向性无明显变化，超热中子与快中子通量比有所提升。
为了比较反射补偿物80分别为铅合金或铝合金和冷却装置20、20′与容纳管道13、13′的间隙中无反射补偿物80(即填充空气)时对超热中子的产率、快中子污染量及照射时间产生的影响，列出表六至表八做详细比较。
其中，表六示出了在不同容纳腔的孔径下，分别填充空气、铝合金、铅合金时超热中子的产率(n/cm 2mA)：
表六：超热中子的产率(n/cm 2mA)
Figure PCTCN2018100787-appb-000006
表七示出了在不同容纳腔的孔径下，分别填充空气、铝合金、铅合金时快中子污染量(Gy-cm2/n)：
表七：快中子污染量(Gy-cm 2/n)
Figure PCTCN2018100787-appb-000007
表八示出了在不同容纳腔的孔径下，分别填充为空气、铝合金、铅合金时被照射体所需要的照射时间(分钟)：
表八：被照射体所需要的照射时间(Min)
Figure PCTCN2018100787-appb-000008
从表六至表八可以看出，在容纳腔孔径相同时，相较于填充空气，填充铅合金或铝合金时，超热中子的产率较高，而快中子污染量和所需要的照射时间较少。
本申请揭示的中子捕获治疗系统并不局限于以上实施例所述的内容以及附图所表示的结构。例如，缓速体可设置成锥形或多边形棱柱体、冷却装置可设置成若干个，而容纳管道对 应地具有若干个等。在本申请的基础上对其中构件的材料、形状及位置所做的显而易见地改变、替代或者修改，都在本申请要求保护的范围之内。

Claims (15)

  1. 一种中子捕获治疗系统，其特征在于：所述中子捕获治疗系统包括射束整形体、设置于射束整形体内的真空管，所述射束整形体包括射束入口、容纳所述真空管的容纳腔、邻接于所述容纳腔端部的缓速体、包围在所述缓速体外的反射体、设置在所述射束整形体内的辐射屏蔽和射束出口，所述真空管端部设有靶材，所述靶材与自所述射束入口入射的带电粒子束发生核反应以产生中子，所述中子形成中子射束，所述中子射束自射束出口射出并限定一根中子射束轴线，所述缓速体将自所述靶材产生的中子减速至超热中子能区，所述反射体将偏离的中子导回至所述缓速体以提高超热中子射束强度，所述辐射屏蔽用于屏蔽渗漏的中子和光子以减少非照射区的正常组织剂量，所述缓速体至少包括两个外直径不同的圆柱体状缓速体，所述缓速体具有靠近射束入口的第一端部和靠近射束出口的第二端部，所述靶材容纳在所述第一端部和所述第二端部之间。
  2. 根据权利要求1所述的中子捕获治疗系统，其特征在于：所述缓速体包括靠近射束入口的第一缓速体和与第一缓速体紧密贴合且靠近射束出口的第二缓速体，所述第一缓速体至少包括两个外直径不同的圆柱体状缓速体，所述射束入口、所述缓速体和所述射束出口均沿着所述中子射束轴线延伸，所述靶材到所述射束出口的距离小于所述第一端部到所述射束出口的距离。
  3. 根据权利要求2所述的中子捕获治疗系统，其特征在于：所述第一缓速体包括三个外直径不同的圆柱体状缓速体，所述第一缓速体包括靠近射束入口的第一缓速部、与第一缓速部紧密贴合的第二缓速部及与第二缓速部紧密贴合的第三缓速部，第一、第二、第三缓速部沿中子射束轴线方向依次排列，第一、第二、第三缓速部与第二缓速体的外直径分别为第一、第二、第三、第四外直径，第一外直径小于第二外直径，第二外直径小于第三外直径，第三外直径等于第四外直径。
  4. 根据权利要求3所述的中子捕获治疗系统，其特征在于：第一缓速部具有靠近射束入口的第一前端面、靠近射束出口的第一后端面及第一外圆周面；第二缓速部具有与第一后端面紧密贴合的第二前端面、靠近射束出口的第二后端面及第二外圆周面；第三缓速部具有与第二后端面紧密贴合的第三前端面、靠近射束出口的第三后端面及第三外圆周面；第二缓速体具有与第三后端面紧密贴合的第四前端面、靠近射束出口的第四后端面及第四外圆周面，第一、第二、第三、第四前端面及第一、第二、第三、第四后端面之间相互平行且均与中子射束轴线垂直，穿过中子射束轴线的切面与第一外圆周面的交线与第二前端面垂直，穿过中子射束轴线的切面与第二外圆周面的交线与第三前端面垂直。
  5. 根据权利要求4所述的中子捕获治疗系统，其特征在于：在穿过中子射束轴线的切面内，第一前端面与第一外圆周面相交得到第一交点，第二前端面与第二外圆周面相交得到第二交点，第三前端面与第三外圆周面相交得到第三交点，第一、第二、第三交点位于同一条直线上。
  6. 根据权利要求1所述的中子捕获治疗系统，其特征在于：所述容纳腔与所述真空管之间填充反射补偿体，所述反射补偿体为铅或Al或铁氟龙或C。
  7. 根据权利要求1所述的中子捕获治疗系统，其特征在于：所述第一端部沿着所述中子射束轴线往所述射束入口的方向突出于所述靶材，所述第二端部沿着所述中子射束轴线往所述射束出口的方向突出于所述靶材。
  8. 根据权利要求1所述的中子捕获治疗系统，其特征在于：所述反射体在中子射束轴线的两侧均凸出缓速体，所述容纳腔包括由反射体围设而成的的反射体容纳腔及自反射体容纳腔延伸由缓速体围设而成的缓速体容纳腔，所述真空管包括容纳在反射体容纳腔内的延伸段及自延伸段延伸并容纳在缓速体容纳腔内的嵌入段，所述靶材设于所述嵌入段的端部。
  9. 根据权利要求1所述的中子捕获治疗系统，其特征在于：所述中子捕获治疗系统还包括至少一个冷却装置，所述射束整形体内设有至少一个容纳冷却装置的容纳管道，所述冷却装置与容纳管道的内壁之间填充有铅合金或铝合金。
  10. 根据权利要求1所述的中子捕获治疗系统，其特征在于：所述中子捕获治疗系统还包括设于射束入口并与射束整形体紧密贴合设置的屏蔽体。
  11. 根据权利要求2所述的中子捕获治疗系统，其特征在于：所述第二缓速体为锥体状或圆柱状或台阶状。
  12. 根据权利要求4所述的中子捕获治疗系统，其特征在于：在穿过中子射束轴线的切面内，第一前端面与第一外圆周面相交得到第一交点，第二前端面与第二外圆周面相交得到第二交点，第三前端面与第三外圆周面相交得到第三交点，第一、第二、第三交点位于一条弧线上。
  13. 根据权利要求2所述的中子捕获治疗系统，其特征在于：所述靶材伸入缓速体的深度小于等于第一缓速体在中子射束轴线方向上的尺寸。
  14. 根据权利要求1所述的中子捕获治疗系统，其特征在于：所述靶材伸入缓速体的深度大于第一缓速体在中子射束轴线方向上的尺寸。
  15. 根据权利要求9所述的中子捕获治疗系统，其特征在于：所述冷却装置包括沿竖直方向布置并位于靶材前方用于冷却靶材的第一冷却部、沿中子射束轴线方向延伸而位于真空管两侧的第二、第三冷却部，第一冷却部连接在第二、第三冷却部之间，第二冷却部向第一冷却部输入冷却介质，第三冷却部将第一冷却部中的冷却介质输出。
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2894548A1 (es) * 2020-08-09 2022-02-14 Univ Granada Dispositivo de produccion, moderacion y conformacion de haces de neutrones para terapia por captura neutronica
WO2022212821A1 (en) * 2021-04-02 2022-10-06 Tae Technologies, Inc. Materials and configurations for protection of objective materials

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2734955C1 (ru) * 2017-06-05 2020-10-26 Нойборон Медтех Лтд. Блок формирования пучка для нейтронно-захватной терапии
WO2019037624A1 (zh) * 2017-08-24 2019-02-28 南京中硼联康医疗科技有限公司 中子捕获治疗系统
WO2019114307A1 (zh) * 2017-12-15 2019-06-20 南京中硼联康医疗科技有限公司 中子捕获治疗系统
CN111821580A (zh) * 2019-04-17 2020-10-27 中硼(厦门)医疗器械有限公司 中子捕获治疗系统及用于中子捕获治疗系统的射束整形体
US11517769B2 (en) * 2019-07-10 2022-12-06 Ricoh Company, Ltd. Neutron beam transmission adjusting device comprising a neutron beam transmission unit including a neutron reactant, method for producing neutron beam transmission adjusting device, and neutron beam adjusting method
CN113724908A (zh) * 2021-08-11 2021-11-30 散裂中子源科学中心 一种热中子束流整形装置
WO2023076407A2 (en) * 2021-10-27 2023-05-04 Tae Life Sciences, Llc Systems, devices, and methods for converting a neutron beam
CN115120893B (zh) * 2022-08-25 2022-11-25 兰州大学 一种硼中子俘获治疗束流整形装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101829409A (zh) * 2009-03-13 2010-09-15 住友重机械工业株式会社 中子射线旋转照射装置
CN105917251A (zh) * 2014-01-14 2016-08-31 住友重机械工业株式会社 中子射线检测装置及中子捕捉疗法装置
CN106798969A (zh) * 2015-11-26 2017-06-06 南京中硼联康医疗科技有限公司 用于中子捕获治疗的射束整形体
WO2017146205A1 (ja) * 2016-02-26 2017-08-31 住友重機械工業株式会社 中性子捕捉療法装置、及び中性子捕捉療法用ターゲット

Family Cites Families (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5174949A (en) * 1991-05-17 1992-12-29 General Electric Company Non circular water rod features
JP3055820B2 (ja) * 1991-07-05 2000-06-26 株式会社東芝 燃料集合体と炉心
US5247551A (en) * 1991-09-24 1993-09-21 Siemens Power Corporation Spacer sleeve for nuclear fuel assembly
US6301321B1 (en) * 1999-07-14 2001-10-09 Yousef M. Farawila Compound water channel system for boiling water reactor fuel assemblies
JP4596392B2 (ja) * 2006-03-08 2010-12-08 三菱重工業株式会社 中性子発生装置及び中性子照射システム
US7919758B2 (en) * 2007-06-19 2011-04-05 Material Innovations, Inc. Neutron detector
AU2007363064B2 (en) * 2007-12-26 2014-02-13 Thorium Power Inc. Nuclear reactor (variants), fuel assembly consisting of driver-breeding modules for a nuclear reactor (variants) and a fuel cell for a fuel assembly
JP5112105B2 (ja) * 2008-02-18 2013-01-09 住友重機械工業株式会社 減速材及び減速装置
US20110090710A1 (en) * 2009-10-15 2011-04-21 Edmund Joseph Kelly High Efficiency Light Pipe
RU2568559C2 (ru) * 2010-07-29 2015-11-20 Дзе Стейт Оф Орегон Эктинг Бай Энд Тру Дзе Стейт Борд Оф Хайер Эдьюкейшн Он Бихаф Оф Орегон Стейт Юниверсити Мишень для получения изотопов
US20130129027A1 (en) * 2011-11-21 2013-05-23 Richard Harris Pantell High Flux Neutron Source
TWI532056B (zh) * 2013-10-15 2016-05-01 財團法人工業技術研究院 濾屏與中子束源
AU2015210075B2 (en) * 2014-01-22 2017-04-20 Cancer Intelligence Care Systems, Inc. Method for manufacturing magnesium fluoride sintered compact, method for manufacturing neutron moderator, and neutron moderator
DK3032927T3 (en) * 2014-12-08 2017-02-06 Neuboron Medtech Ltd RADIATING DEVICE FOR NEUTRON COLLECTION THERAPY
EP3570294B1 (en) * 2015-05-04 2020-12-23 Neuboron Medtech Ltd. Beam shaping body for neutron capture therapy
JP6712636B2 (ja) * 2015-09-28 2020-06-24 南京中硼▲聯▼康医▲療▼科技有限公司Ｎｅｕｂｏｒｏｎ Ｍｅｄｔｅｃｈ Ｌｔｄ． 中性子捕捉療法システム用のビーム診断システム
JP6722281B2 (ja) * 2015-09-30 2020-07-15 南京中硼▲聯▼康医▲療▼科技有限公司Ｎｅｕｂｏｒｏｎ Ｍｅｄｔｅｃｈ Ｌｔｄ． 中性子捕捉療法に用いられるビーム整形体
RU2717364C1 (ru) * 2015-11-12 2020-03-23 Нойборон Медтех Лтд. Система нейтрон-захватной терапии
RU2717363C1 (ru) * 2015-11-26 2020-03-23 Нойборон Медтех Лтд. Блок формирования пучка для нейтрон-захватной терапии
EP3395404B1 (en) * 2016-01-08 2020-08-19 Neuboron Medtech Ltd. Beam shaper for neutron capture therapy
EP3632509B1 (en) * 2016-01-15 2022-08-31 Neuboron Medtech Ltd. Neutron capture therapy system
JP6732244B2 (ja) * 2016-03-25 2020-07-29 株式会社八神製作所 中性子減速照射装置
JP6754846B2 (ja) * 2016-04-19 2020-09-16 南京中硼▲聯▼康医▲療▼科技有限公司Ｎｅｕｂｏｒｏｎ Ｍｅｄｔｅｃｈ Ｌｔｄ． βアミロイド沈着プラークを除去するための中性子捕捉治療システム
WO2018006551A1 (zh) * 2016-07-04 2018-01-11 南京中硼联康医疗科技有限公司 中子治疗装置
TWI614042B (zh) * 2016-12-02 2018-02-11 財團法人工業技術研究院 中子束源產生器及其濾屏
US20180172852A1 (en) * 2016-12-19 2018-06-21 David Edward Newman Dual-Scintillator Neutron-Gamma Detector
RU2734955C1 (ru) * 2017-06-05 2020-10-26 Нойборон Медтех Лтд. Блок формирования пучка для нейтронно-захватной терапии
WO2019114307A1 (zh) * 2017-12-15 2019-06-20 南京中硼联康医疗科技有限公司 中子捕获治疗系统
JP6947934B2 (ja) * 2017-12-18 2021-10-13 南京中硼▲聯▼康医▲療▼科技有限公司Ｎｅｕｂｏｒｏｎ Ｍｅｄｔｅｃｈ Ｌｔｄ． 中性子捕捉療法システム

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101829409A (zh) * 2009-03-13 2010-09-15 住友重机械工业株式会社 中子射线旋转照射装置
CN105917251A (zh) * 2014-01-14 2016-08-31 住友重机械工业株式会社 中子射线检测装置及中子捕捉疗法装置
CN106798969A (zh) * 2015-11-26 2017-06-06 南京中硼联康医疗科技有限公司 用于中子捕获治疗的射束整形体
WO2017146205A1 (ja) * 2016-02-26 2017-08-31 住友重機械工業株式会社 中性子捕捉療法装置、及び中性子捕捉療法用ターゲット

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3708224A4 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2894548A1 (es) * 2020-08-09 2022-02-14 Univ Granada Dispositivo de produccion, moderacion y conformacion de haces de neutrones para terapia por captura neutronica
WO2022034257A1 (es) * 2020-08-09 2022-02-17 Universidad De Granada Dispositivo de producción, moderación y conformación de haces de neutrones para terapia por captura neutrónica
WO2022212821A1 (en) * 2021-04-02 2022-10-06 Tae Technologies, Inc. Materials and configurations for protection of objective materials

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