High Efficiency and Bright Neutron Converter Screens

The DOE is planning to restart work at one or both of the research reactors at Idaho National Laboratory (Transient Reactor Test Facility) and Sandia National Laboratories (Annular Core Research Reactor). Neutron radiography plays a large role in the work done at these facilities and there is a desire (described in the 2009 workshop proceedings of Future Transient Testing of Advanced Fuels) to upgrade their neutron imaging capabilities which encompass relatively unique conditions due to the highly radioactive materials that are often imaged. RMD is proposing a new neutron radiography technology based upon a new scintillator material that has high light output. The material(s) are Gd-based garnets that are formed through ceramic processing. RMD will be examining how this technology can be adapted to producing large thin layers and will accordingly evaluate the optical and detection properties, before moving to a next stage of integration with photodetector readouts. RMD will be evaluating how this Gd-based garnet ceramic material can be fabricated into large areas that are conducive to radiography. One approach will be to produce the ceramics as thick blanks and process them into thin layers which can then be tiled to form large area mosaics. A second approach will be to mix the powders with appropriate binders and create large areas through either screen printing or tape casting techniques. All forms will be characterized for various qualities such as luminosity, uniformity, and spatial resolution. Commercial Applications and Other Benefits: With the increased interest and commitment to quality control, many industrial groups are developing neutron based non-destructive testing equipment. High counting rates and high sensitivity are important to minimize the required source strength, which must be located on the production floor. This is an area in which the compactness, and flexibility of a high performance detector will have a major impact. Other potential applications include nuclear treaty verification and safeguards, environmental monitoring, nuclear waste cleanup, homeland security and geological exploration.