Research Of Accelerator-based Boron Neutron Capture Therapy

With characters of high neutron yield and low threshold energy,7Li(p,n)reaction appears outstanding among many of Neutron generating reaction for Accelerator-based BNCT. This articles systematically researched the progress from the generation of spallation Neutron and then the moderation,shaping to the final dose calculation analysis.Due to the spallation neutron spectrum from the near Threshold energy reaction is uncommon in the references home and abroad, the first part calculated yield and energy and angular distribution of differential spectrum of Spallation Neutron generated by incident proton with energy from 1.9 to 3.0 MeV using Monte Carlo code MCNPX 2.6.0. A detailed study of spallation Neutron energy spectrum by 2.5 MeV incident Proton was also conducted. the validity of calculation data was verified by the overseas experimental data,the spallation Neutron spectrum information was sotored by writing surface source card-SSW for the following use.Because the initial neutron energies is too high for boron neutron capture therapy use,before radiating on the human body high-energy neutrons need to be moderated and reshaped to meet requirements of treatment beam. Based on four types of neutron-reflecting material,three types of neutron moderation materials and optimum design of device geometry, conclusion that three moderated material can well meet the requirements of boron neutron capture therapy treatment was obtained,and Neutron spectrum information was stored By writing surface source card-SSW for the fllowing use.By reading the former source though source reading card-SSR, the moderated epithermal neutron beam was used to calculate doses distribution within the human brain, the calculation data further verify the feasibility of Accelerator-based neutron capture therapy,in the same time,two ways of precise dose distribution calculation including the Mesh and Vox tally are compared.Conclusion: spallation neutrons by 10 mA of 2.5 MeV incident proton beam,after moderating can meet boron neutron capture therapy well.The foregoing findings has a great deal of help to Accelerator based boron neutron capture therapy research,and will accelerate progress of domestic boron neutron capture therapy.