PFI:AIR-TT: Portable Neutron Detector Implementing PIN detectors and Application Specific Circuitry (ASIC)

University Of Texas At Dallas, Richardson TX

Investigators

Abstract

This PFI: AIR Technology Translation project focuses on translating research on solid state neutron detectors based on silicon p-i-n diodes coupled with a 10B neutron conversion layer. Low cost, high performance portable neutron detectors will have applications ranging from homeland security to medical treatment. First responders will be able to continuously monitor for the presence of special nuclear materials, providing a distributed, networked array of detectors covering the entire country, making it nearly impossible to move special nuclear materials without being detected. Medical physicists will be able to monitor the production of neutrons during heavy ion cancer treatment to collect data on the long term impact of secondary neutrons. The technology is based on research that resulted in detectors that have shown >13% intrinsic thermal neutron detection efficiency. Currently, most portable neutron detectors are based on 3He-filled tubes. While these detectors have been the workhorse of the nuclear industry for many years, they require high voltage and they are fragile, bulky, and too expensive to be widely distributed. There is a need for high efficiency neutron detectors that are rugged, low cost, low power and that can be networked together. This PFI program involves the University of Texas at Dallas working closely with Texas Instruments to develop the electronics to tile many small solid state neutron detectors together into an array that will provide performance similar to commercially available 3He detectors at a greatly reduced cost. This project addresses several technology gap(s) as it translates from research discovery toward commercial application. For example, this program will couple highly efficient neutron detector elements with high performance signal processing electronics made from state-of-the-art silicon CMOS, based on an ASIC (application specific integrated circuit) that has at least 25 channels of pre-amplification and pulse shaping circuitry, with one channel coupled to each 1 cm2 detector element. This will allow the demonstration of a 25 cm2 solid state neutron detector array with performance equivalent to a conventional 3He detector. Simulations show that the high performance, low noise electronics should enable 20% intrinsic thermal neutron detection efficiency. Because all of the electronics are combined in one ASIC, the cost of the electronics can be reduced from approximately $1200 using discreet components for each channel, to <$10 for the entire array. Because of the greatly reduced cost, portable neutron detectors would be available for applications never before possible. This project will support two graduate students who will be trained in the area of radiation detectors and nuclear electronics. This is quickly becoming a lost skill set and there is a need for the next generation of engineers and scientists that understand radiation detectors and the associated electronics. The students will also have the opportunity to work with engineers and scientists at Texas Instruments, the leader in the field of analog and mixed signal electronics. This is an opportunity to which few students have access.