Measurement of the Fast Neutron Energy Spectrum of an $^{241}{\rm Am!-!Be}$ Source Using a Neutron Scatter Camera

We have measured the neutron energy spectrum of an ²⁴¹Am-Be(α,n) source between 1.5 MeV and 9 MeV using a neutron scatter camera. The apparatus consists of two segmented planes each with 16 liquid scintillator cells (Eljen EJ-309), for a total of 32 elements; the neutron energy spectrum is measured using double elastic scatter events. After unfolding resolution effects using a maximum likelihood technique, the measurement is compared to reference Am-Be spectra. Further, we discuss the ability of the neutron scatter camera to distinguish between an Am-Be source and a spontaneous fission source.