Spatial Resolution and Directional Uniformity of the Portable Fast-Neutron Imager

We evaluate the spatial resolution and the directional uniformity of the fast-neutron imager with a
²⁵²
Cf source. The imager is composed of Li-glass scintillators and a spherical polyethylene moderator, which is utilized for nuclear security and radiation-protection application. The result shows that the angular resolution measured at 2 m from the source is reached better than 15 degrees with the fluence of 2.5×10
³
n/cm
²
. We check the detection sensitivity and the reconstructed source position by rotating horizontally with an automated stage. Uniform sensitivity within 1% level is confirmed for entire directions.