Very Large Area Microchannel Plate Neutron Detectors

NOVA Scientific, Inc., teamed with the Electronics Group of Oak Ridge National Laboratory, proposes to construct very large area Microchannel Plate neutron detectors. The applications of these much larger format detectors will serve an exceptionally broad range of government agencies from neutron scattering detectors for DOE to nuclear material panel detectors for NNSA, and ultimately to nuclear medicine for NIH and military field operations for DoD. The collaboration benefits from NOVAs knowledge and development of neutron-sensitive MicroChannel Plate (MCP) detectors and from the expertise of the Oak Ridge electronics group in the readout of high event rate and low noise detectors. The proposed program will represent a remarkable step forward in high rate neutron imaging. Past neutron detectors have been constructed using 3He gas tubes, which offer both high thermal neutron detection efficiency as well as excellent discrimination between neutrons and interfering gamma rays. More recently, however, the sources of 3He gas are being quickly expended, severely constraining a variety of neutron detection applications such as scientific instrumentation and Homeland Security. This constraint has forced all end-users to seek alternative detection methods with an emphasis on solid-state neutron detectors. NOVA has developed neutron-sensitized, solid-state MCP detectors that exhibit neutron detection efficiencies and gamma rejection equal to or better than that of the conventional 3He gas tubes, albeit in small sizes. This program will construct much larger systems coupled with the pixilated electronic readouts being developed by Oak Ridge. The product developed will be a large area neutron imaging detector, capable of spatial resolutions of ~1 mm, good timing resolution, low noise, high flux capabilities, and excellent detection capabilities for both cold and thermal neutrons. It will incorporate electronic power-up and pixilated readouts that can archive data for further centroid averaging. New neutron scattering facilities, notably the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, provide much higher flux than existing sources, translating into much higher detector flux requirements. Such instrumentation will require better position resolution and rate capability than available with existing technologies, along with the continuing requirements of gamma rejection and stability. These characteristics of this large detector are highly desired and will be a critical step in development of a solid-state converter to fully replace 3He detectors, now a limited national resource. NOVA has provided a significant number of state-of-the-art neutron imaging detectors at national laboratories and leading universities within the USA. This program will leapfrog current neutron detector performance and will serve to maintain US leadership in materials research and neutron technology.