本研究計畫利用多球體中子能譜評估系統(Boron Sphere spectrometer, BSS)，以不同尺寸大小(0, 2, 3, 5, 8, 10 及12英吋)的聚苯乙烯(polystyrene)球包覆金箔晶片的方法，測量妹(Cf-252)射源發射之中子。將不同波納球大小 所測量到的金箔活化之計數率，由UMG 3.3軟體展開(Unfolding)後可評估得中子能譜，並對結果與國際文獻進行 比較及探討，以建立適合偵測高能粒子放射治療照野内大信號之誘發的中子能譜評估技術。

The project used a neutron spectroscopy system (Bonner Sphere spectrometer, BSS), including polystyrene multi-spheres in various sizes of 0, 2, 3, 5, 8, 10 and 12 inch diameters, by means of putting gold foils inside the spheres, to measure the neutron energy spectrum emission from the Cf-252 source. The counting rates of neutron-activated gold foils in different sphere sizes were measured, and after unfolding by means of the UMG 3.3 software code, the neutron spectrum was also evaluated. The evaluated Cf-252 spectrum was compared to the literatures and relative discussion was made to build the proper method to measure the induced neutron spectrum in field area which contributed the huge signal in high energy particle radiotherapy.