On the Study of Energy Spectra and Angular Distributions of the Neutrons Emitted from a Beryllium Target Bombarded with 4-MeV Protons for Neutron Capture Therapy
Due to the recent advancement of the technologies in high-current proton accelerators, neutron sources based on 2.5 MeV proton bombarding a lithium (Li) target have been vigorously studied in the past few years1,2 and was thought to be feasible for neutron capture therapy (NCT). Neutrons are generated based on the 7Li(p,n)7Be reactions and then moderated with beryllia (BeO) or heavy water (D2O). For a treatment time of 1 hour it was determined that a proton current of 30 mA might be necessary. This intense proton beam is achievable with the newly available radio-frequency quadrupole (RFQ) accelerator3. However, because Li has a low melting point (179°C) and a low thermal conductivity (45 W/m°C), the removal of the immense heat (75 kW) from the Li target imposes a big challenge on the target design. In addition, Li is very reactive chemically, and it thus further complicates the target design in order to provide proper access for system maintenance4.
KeywordsLithium Boron Beryllium
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- 1.C.K. Wang, T.E.Blue, and R. Gahbauer, A neutronic study of an accelerator-based neutron irradiation facility for boron neutron capture therapy, Nuclear Technology, 84:93 (1989).Google Scholar
- 3.Private communication with R.W. Hamm, AccSys Technology, Inc., 1177A Quarry Lane, Pleasanton, CA 94566.Google Scholar
- 4.P.E. Eggers, C.K. Wang, and H. Crawford, A design study of a low-energy proton accelerator neutron irradiation facility consisting a rotating target cooling system for neutron capture therapy, this Proceedings.Google Scholar
- 7.H.H. Anderson and J.F. Ziegler. “Hydrogen: Stopping Powers and Ranges of Ions in Matter,” Pergamon Press, Inc., Maxwell House, NY (1977).Google Scholar