Development of a Portable $^{10}{\hbox{B}}$ -Based $^{3}{\hbox{He}}$ Replacement Neutron Detector

Rapiscan Laboratories and Helicon Thin Film Systems have designed and developed a detector for the replacement of 3 He-based detector modules. Our neutron detector consists of a thinly coated 10 B flat-panel ionization chamber that can be deployed as a direct drop-in replacement for current RPM 3 He detectors. The uniqueness of our approach in providing a large-area detector is the simplicity of construction, scalability of the unit cell detector, ease of adaptability to a variety of applications, and low cost. In the initial development, a smaller area, multi-layer prototype nat B 4 C-based ionization chamber was built and tested, demonstrating neutron detection capability and gamma-ray insensitivity. In the subsequent stage of detector development, enriched 10 B 8 C films were robustly deposited, passed temperature cycling testing, and were tested in the prototype chamber for neutron sensitivity. In addition to the development of the boron-coated substrates, a complete signal processing circuit, which includes a preamplifier, amplifier, and discriminator, was fabricated on a circuit board and tested within the prototype chamber. Currently, a portable detector has been tested.