Douglas McGregor is the director of the SMART Lab at Kansas State University. McGregor is currently pursuing several different research projects such as growing high-purity crystals and finding new ways to detect neutrons without having to place the equipment in the radiation field. The total budget from all of the projects currently in progress is about 1.7 million dollars.

One of the McGregor's projects was to create self-biased neutron detectors. These semiconductor detectors are made out of lOB-coated high-purity GaAs films. The devices use lOB to interact with incoming neutrons to give off 7Li ions and alpha particles, which can then be collected and measured. The research showed that the neutron-detection efficiency was best for a thick lOB coating, while the energy resolution was better with a thin lOB coating. One of the major benefits to this type of detector is that it operates under its own bias and does not require a large power supply. Thus, the detectors can be placed in remote locations far from a power supply and still operate.

McGregor has also worked on increasing the efficiency of thin-film- coated semiconductor neutron detectors. These devices had been used for years with a maximum detection efficiency of 3.95% with a lOB coating and 4.3% with a 6Li coating. Three changes were made to increase the detection efficiency. The first was to face two detectors toward each other with a reactive film between them. The second was to apply one film over the other. The third was to create small holes in the surface of the detector that can be filled with neutron-reactive materials. These three changes resulted in a more than 300% increase in neutron- detection efficiency.

McGregor has also worked on creating and improving gamma ray detectors. One detector took advantage of three effects, a Frisch grid, geometric weighting, and the small pixel effect. These worked together to produce excellent gamma ray energy resolution at room temperature with no electronic correction. The increases in energy resolution allow lower grade detector material to be useful for measuring energy of incoming radiation as opposed to just counting the number of interactions.

The research done by McGregor and his students has been of great interest to the nuclear industry as well as organizations devoted to the defense of our country. Argonne National Labs, Lawrence Livermore National Labs, the Defense Threat Reduction Agency, and the Department of Energy are currently funding McGregor?s research.

Josh Van Meter, MNE Junior