A detector for 2-D neutron imaging for the spallation neutron source

We have designed, built, and tested a 2-D pixellated thermal neutron detector. The detector is modeled after the MicroMegas-type structure previously published for collider-type experiments. The detector consists of a 4/spl times/4 square array of 1 cm/sup 2/ pixels each of which is connected to an individual preamplifier-shaper-data acquisition system. The neutron converter is a /sup 10/B film on an aluminum substrate. We describe the construction of the detector and the test results utilizing /sup 252/Cf sources in Lucite to thermalize the neutrons.