Speaker
Description
Accurate neutron beam profiling and position verification are required for alignment, improvement of signal-to-noise, and imaging development, yet are often performed with single-use beam-imaging media that provide only integrated exposure and limited real-time feedback. We present a first analysis of neutron imaging data from the Device for Indirect Capture Experiments on Radionuclides (DICER) at the Los Alamos Neutron Science Center (LANSCE), using the Large Area Picosecond Photodetector (LAPPD) coupled to an 8″×4″ ⁶Li-glass scintillator. The 8″×8″ LAPPD employs a resistive internal anode capacitively coupled to a replaceable external 8×8 readout plane of 1″×1″ pads; despite the coarse segmentation, measurable lateral charge sharing enables sub-pad localization via charge-weighted centroiding.
The detector was installed at the downstream end of flight path 13 where collimation delivers two neutron beams to the detector region, including a transmission beam containing a $^{149}$Sm sample. We develop an event-building and clustering approach tailored to scintillator-coupled operation, using a fixed coincidence window to group multi-pad responses, enforcing spatial consistency around the highest-charge pad, and reconstructing interaction position from the charge centroid of adjacent pads. For one day of sample-in data, preliminary results show typical coincident clusters spanning slightly more than three pads and demonstrate millimeter-scale localization relative to the 1″ pad pitch. These results highlight the potential of an LAPPD+⁶Li-glass system as a reusable detector for neutron beam visualization and, ultimately, position-resolved transmission measurements; ongoing work includes optimized selections and calibrations and validation with radionuclide sources and patterned neutron masks.