Neutron capture therapy system and target for particle beam generating device

Abstract

A neutron capture therapy system and a target for a particle beam generating device, which may improve the heat dissipation performance of the target, reduce blistering and extend the service life of the target. The neutron capture therapy system includes a neutron generating device and a beam shaping assembly. The neutron generating device includes an accelerator and a target, and a charged particle beam generated by acceleration of the accelerator interacts with the target to generate a neutron beam. The target includes an acting layer, a backing layer and a heat dissipating layer, the acting layer interacts with the charged particle beam to generate the neutron beam, the base layer supports the action layer, and the heat dissipating layer includes a tubular member composed of tubes arranged side by side.

What is claimed is: 
     
         1 . A target for a particle beam generating device, wherein the target comprises:
 an acting layer for generating the particle beam,   a backing layer for supporting the acting layer, and   a heat dissipating layer including a tubular member composed of tubes arranged side by side.   
     
     
         2 . The target for a particle beam generating device according to  claim 1 , wherein the target further comprises an oxidation resistant layer, and a material of the oxidation resistant layer includes at least one of Al, Ti, Be and an alloy thereof or stainless steel, an adhesion layer is disposed between the acting layer and the backing layer, and a material of the adhesion layer includes at least one of Cu, Al, Mg, or Zn, the heat dissipating layer is made of a heat conductive material or a material for both heat conduction and blistering suppression, the backing layer is made of a material for suppressing blistering, the material for suppressing blistering or the material for both heat conduction and blistering suppression includes at least one of Fe, Ta or V, the heat dissipating layer and the backing layer are connected by a HIP process, and the acting layer and the backing layer are connected by a casting, evaporation or sputtering process. 
     
     
         3 . The target for a particle beam generating device according to  claim 1 , wherein the tubular member simultaneously serves as the backing layer, a material of the tubular member is Ta, and the acting layer and the tubular member are connected by an evaporation or sputtering process. 
     
     
         4 . The target for a particle beam generating device according to  claim 1 , wherein a material of the backing layer is Ta—W alloy, and a mass percentage of W in the Ta—W alloy is 2.5% to 20%, an energy of the proton beam is 1.881 MeV to 10 MeV, and a thickness of the backing layer is at least 50 μm. 
     
     
         5 . The target for a particle beam generating device according to  claim 1 , wherein the acting layer on each tube of the tubular member covers at least ¼ of the outer circumference of the tube, the acting layer is at an angle of at least 45 degrees from the centerline of the tube in the circumferential direction, the tubular member forms a connecting portion between adjacent tubes, the connecting portion is composed of a backing layer, an acting layer and an oxidation resistant layer. 
     
     
         6 . The target for a particle beam generating device according to  claim 1 , wherein the heat dissipating layer further comprises a support member, a material of the support member is Cu, the tubular member and the support member are welded or detachably connected or integrally formed by additive manufacturing, the support member and/or the tubular member comprise a cooling passage. 
     
     
         7 . The target for a particle beam generating device according to  claim 6 , wherein the support member comprises a first support portion and a second support portion disposed at both ends of the tubular member, the support member further comprises a third support portion connecting the first and second support portions, the third support portion is in contact with another side opposite to a side of the tubular member connecting the acting layer, cooling medium passes only through the support member, or both through the interior of each tube of the tubular member and the third support portion of the support member, or both through the interior of each tube and the first, second and third support portions of the support member. 
     
     
         8 . The target for a particle beam generating device according to  claim 7 , wherein the first support portion comprises a cooling inlet and a first cooling passage, the second support portion comprises a cooling outlet and a second cooling passage, the cooling medium enters interior of each tube of the tubular member through the first cooling passage from the cooling inlet, and then exits the cooling outlet through the second cooling passage, the cooling medium is water. 
     
     
         9 . A target for a particle beam generating device, wherein the target comprises:
 an acting layer for generating the particle beam,   a backing layer for supporting the acting layer, and   a heat dissipating layer including a cooling passage through which a cooling medium circulates, wherein at least one protruding portion is disposed in the cooling passage, and the protruding portion comprises a cooling surface.   
     
     
         10 . The target for a particle beam generating device according to  claim 9 , wherein the protruding portion protrudes from an inner wall of the cooling passage in a direction perpendicular to or oblique to a flow direction of the cooling medium, the protruding portion extends in a spiral or linear shape from the inner wall of the cooling passage in the flow direction of the cooling medium, or the protruding portion is a ring that is spaced apart in the direction of flow of the cooling medium or a part of the ring. 
     
     
         11 . The target for a particle beam generating device according to  claim 9 , wherein the protruding portion is integral with the cooling passage or the protruding portion is separately formed and mounted in the cooling passage, and the cooling surface is provided with a sub-protruding portion. 
     
     
         12 . The target for a particle beam generating device according to  claim 10 , wherein the cross-sectional shape of the protruding portion in the direction perpendicular to the flow direction of the cooling medium is a rectangle, a trapezoid or a triangle; different cross sections have different shapes or sizes, and are pulsed, serrated or wavy in the flow direction of the cooling medium. 
     
     
         13 . The target for a particle beam generating device according to  claim 10 , wherein in the direction perpendicular to the flow direction of the cooling medium, a maximum distance that the protruding portion extends from the inner wall of the cooling passage is less than half the distance that extends to the opposite inner wall in the extending direction, and at least two adjacent protruding portions have different shapes and/or protruding lengths, wherein the protruding portion is at least partially disposed on the inner wall of the cooling passage that is in contact with the acting layer or the backing layer. 
     
     
         14 . The target for a particle beam generating device according to  claim 9 , wherein at least one second wall is disposed in the cooling passage to divide the cooling passage into at least two independent sub-passages, and the flow directions of the cooling medium are different in the at least two adjacent sub-passages. 
     
     
         15 . The target for a particle beam generating device according to  claim 9 , wherein the heat dissipating layer comprises a tubular member composed of tubes arranged side by side, the interior of the tubes at least partially forms the cooling passage, the tubes are formed by additive manufacturing, an inner wall of the cooling passage is a cylindrical surface, the protruding portion is a strip part protruding from the inner wall of the cooling passage in the direction perpendicular to a flow direction of cooling medium and extending linearly in the flow direction of the cooling medium, the protruding portion are plural and are evenly distributed circumferentially along the inner wall of the cooling passage. 
     
     
         16 . A target for a neutron beam generating device, wherein the target comprises:
 an acting layer for interacting with an incident particle beam to generate the neutron beam, wherein the acting layer comprises a first acting layer and a second acting layer, and the incident particle beam sequentially penetrates through the first acting layer and the second acting layer in the incident direction, and   a backing layer for both suppressing blistering caused by the incident particle beam and supporting the acting layer.   
     
     
         17 . The target for a neutron beam generating device according to  claim 16 , wherein materials of the first and second acting layers are both materials for undergoing nuclear reaction with the incident particle beam, and the materials of the first and second acting layers are different. 
     
     
         18 . The target for a neutron beam generating device according to  claim 17 , wherein the material of the first acting layer is Be or an alloy thereof, and the material of the second acting layer is Li or an alloy thereof, the incident particle beam is a proton beam, the first and second acting layers respectively undergo  9 Be(p, n) 9 B and  7 Li(p, n) 7 Be reaction with the proton beam to generate neutrons, an energy of the proton beam is 2.5 MeV-5 MeV, and a neutron yield is 7.31E-05 n/proton −5.61E-04 n/proton. 
     
     
         19 . The target for a neutron beam generating device according to  claim 16 , wherein the first acting layer has a thickness of 5 μm to 25 μm, and the second acting layer has a thickness of 80 μm to 240 μm. 
     
     
         20 . The target for a neutron beam generating device according to  claim 16 , wherein the second acting layer and the backing layer are connected by a casting, evaporation or sputtering process, and the first acting layer seals the backing layer to form a cavity and/or surrounds the second acting layer by HIP processing.