Neutron Energy Spectrum Distributions Surrounding an AmBe Source and a Medical Linear Accelerator*

In a collaboration between Suffolk University and Massachusetts General Hospital, we have used multiple detection methods to determine the neutron energy spectrum of both an AmBe source and a 15 MV medical linear accelerator (LINAC). These detection methods include: high purity metal foil activation, bubble neutron detectors, and organic liquid scintillation. These methods allowed us to study the neutron energy spectrum distribution of each source. The high purity metal foils were layered to allow for localized energy neutron capture in both the thermal and epithermal regions of 0.025 eV to 250 keV. The neutron bubble detectors were used to provide evidence of a 1/r^2 distribution as well as the neutron fluence in the region of 250 keV to 15 MeV. The organic liquid scintillator was used to determine the neutron flux as well as the energy distribution in the region of 200 keV to 15 MeV.