Neutron generating target for neutron beam systems

Abstract

Embodiments that are directed to a target for producing a high epithermal neutron yield for boron-neutron capture therapy (BNCT) treatments are disclosed. The target includes a thin flat film of solid lithium mounted onto a heat-removal support structure that is cooled with a liquid coolant and configured to maintain the turbulent flow regime for a liquid coolant and distribute the flow of coolant directed at the center of the support structure toward a periphery of the support structure via a plurality of channels formed in the support structure. The support structure includes a nozzle located at its center to direct coolant flow outwardly from the center to avoid stagnant water flow at the center of the support structure. Systems, device, and methods utilizing the approaches are also described.

1 - 11 . (canceled) 
     
     
         12 . A method, comprising:
 propagating a charged particle beam from an ion source, through a pre-accelerator, through a tandem accelerator, and along a beamline toward a neutron generating layer of a target to form a neutron beam, wherein the target is enclosed in a cap secured to the beamline and the neutron generating layer is on a side of the target facing the beamline; and   cooling the target using a nozzle protruding from a center of a target support structure facing a cooling inlet of the cap, wherein the nozzle is configured to direct a flow of coolant from the cooling inlet outwardly through a plurality of cooling channels extending along the support structure to a plurality of cooling outlets at a periphery of the cap.   
     
     
         13 . The method of  claim 12 , wherein the target is enclosed in the cap and beamline such that a vacuum seal is present between the target and an interior volume of the beamline, and a water seal is present between the target and the cap. 
     
     
         14 . The method of  claim 12 , wherein the neutron generating layer comprises Lithium. 
     
     
         15 . The method of  claim 12 , wherein the plurality of channels form a configuration of parallel spiral windings. 
     
     
         16 . The method of  claim 12 , further comprising:
 directing, using the cooling inlet, coolant in a downstream to upstream direction with respect to a beam axis.   
     
     
         17 . The method of  claim 16 , further comprising:
 directing, using the plurality of cooling outlets, coolant in an upstream to downstream direction with respect to the beam axis.   
     
     
         18 . The method of  claim 12 , wherein the target further comprises an interlayer interposing the neutron generating layer and the target support structure. 
     
     
         19 . The method of  claim 18 , wherein the interlayer comprises one of pure Ta, Ti, Pd, Nb, V, Ni, or alloys of thereof with themselves or/and with copper. 
     
     
         20 . The method of  claim 12 , further comprising:
 positioning a protective layer over a side of the neutron generating layer facing the beamline.   
     
     
         21 . The method of  claim 12 , wherein each cooling channel of the plurality of cooling channels follows a curved path along the support structure, and wherein a channel surface of each cooling channel comprises a curved transition between a bottom of the channel surface and a side of the channel surface. 
     
     
         22 . A neutron beam system, comprising:
 an ion source configured to generate a charged particle beam;   a pre-accelerator configured to accelerate the charged particle beam;   a tandem accelerator configured to further accelerate the charged particle beam; and   a target configured to generate a neutron beam from the charged particle beam, the target comprising:
 a heat-removal support structure comprising a nozzle protruding from a center of the heat-removal support structure, and 
 a layer of neutron generating material mounted on the heat-removal support structure, 
   wherein the heat-removal support structure comprises a plurality of channels formed in a surface of the heat-removal support structure and configured to distribute a flow of coolant directed at the center of the heat-removal support structure toward a periphery of the heat-removal support structure.   
     
     
         23 . The neutron beam system of  claim 22 , wherein the neutron generating material comprises Lithium. 
     
     
         24 . The neutron beam system of  claim 22 , wherein the heat-removal support structure is configured to accommodate a heat flux of up to about 3-4 MW/m 2 . 
     
     
         25 . The neutron beam system of  claim 22 , wherein the plurality of channels form a configuration of parallel spiral windings. 
     
     
         26 . The neutron beam system of  claim 25 , wherein the configuration of parallel spiral windings evenly distribute cooling across a maximum area of the surface of the heat-removal support structure. 
     
     
         27 . The neutron beam system of  claim 22 , wherein the heat-removal support structure is made of one of copper, copper-diamond powder composites, or CVD diamond. 
     
     
         28 . The neutron beam system of  claim 22 , further comprising:
 an interlayer interposing the layer of neutron generating material and the heat-removal support structure.   
     
     
         29 . The neutron beam system of  claim 28 , wherein the interlayer comprises one of pure Ta, Ti, Pd, Nb, V, Ni, or alloys thereof with themselves and/or copper. 
     
     
         30 . The neutron beam system of  claim 22 , further comprising:
 a protective layer positioned on top of the layer of neutron generating material.   
     
     
         31 . The neutron beam system of  claim 22 , wherein the tandem accelerator is configured to strip electrons from the charged particle beam.