Development of a naNomaterial aNode for a low voltage proportional counter for neutron detection

The objective of this technology transfer effort is to leverage technology developed at Savannah River National Laboratory (SRNL) to develop a portable proportional counter (PC) for neutron detection. NanoTechLabs Inc. (NTL) will develop a portable proportional counter for neutron detection utilizing nanostructured field emitters. Unlike traditional proportional counters, which are typically arranged in a cylindrical geometry, the nano-PC will be arranged in parallel plate geometry. The concept is based on a controlled array of nanoscale anodes to detect the reaction products produced by the interaction of a neutron with boron-10. NTL is working on a new design to fabricate boron-coated or boron-containing nanotube arrays. These nanostructured arrays will be incorporated on a substrate, and subsequent substrates can be stacked to get further field enhancement and more signal strength. Overall sensitivity of the B-lined tubes is dependent on the tube surface area; configurations that increase surface area are a valid solution for increasing their efficiency. The focus of the Phase I efforts will be to prepare and demonstrate growth of nanotube arrays at appropriate geometry for use in PC anodes, demonstrate the efficacy of the boron coating, and performance testing of the anodes at SRNL. Commercial Applications and Other Benefits: Proportional counters are common in many areas of the nuclear industry (i.e., nonproliferation and safeguards, materials processing, remediation and storage) because they are capable of distinguishing between a wide range of radiation types and energies. They are vital to national security as they can be used to detect illicit trafficking of radioactive materials, which could mean the planning of a dirty bomb attack. A limiting factor of common PCs is transportability due to their reliance on a very high and stable voltage source. While this dependence is mitigated by the use of step-up transformers to increase the voltage from a portable battery supply, as monitoring for illegal transport of radioactive materials at borders, seaports, and airports increases there is a need for detection devices that are easily portable, run on small portable power supplies for long periods of time, and have high detection efficiencies. Other advantages of a nano-PC include lower operating voltage, reduced platform size and cost, and improved ruggedness.