Development of a Portable Pixelated Fast-Neutron Imaging Panel

Oak Ridge National Laboratory is developing a portable, pixelated fast-neutron imaging panel for associated particle imaging (API). The panel consists of new and commercially available hardware. Unlike the current generation of API-based neutron imaging systems, this panel is intended to be field deployable. A $30\times30$ array of optically isolated 1 cm $\times$ 1 cm $\times$ 5 cm pulse shape discriminating (PSD) plastic scintillator pixels are optically coupled to a $6\times6$ array of position-sensitive photomultiplier tubes (PMTs) allowing each pixel to be resolved. Each quadrant of $3\times3$ PMTs recombines the 576 PMT anodes using a resistive charge division network to achieve four-corner readout that preserves the average position of the detected light. The design of the panel and initial testing of the light collection and position encoding electronics is presented herein.