Mixed Diphenylacetylene-Stilbene Crystals for Fast Neutron Detection

For this Phase I effort, we will develop growth and fabrication techniques for mixed diphenylacetylene (DPAC)-stilbene crystals, and evaluate the potential for commercialization of this new fast neutron detection material. Fast neutron detection materials and devices are desired for nuclear nonproliferation, homeland security, and basic research activities. Crystalline organic scintillators, such as stilbene, can have very high scintillation efficiency and permit pulse shape discrimination between neutron and gamma events. Availability of these materials has historically been limited due to difficulties in crystal growth using melt techniques. Recently, numerous organic scintillators have been produced using solution growth, in a system analogous to the industrial growth of large crystals of KDP. In addition to the growth of well-known materials, new organic scintillators have been identified with properties potentially superior to stilbene. One outstanding material is mixed crystals of DPAC and stilbene. At Inrad Optics, we have demonstrated solution growth of stilbene and fabrication of stilbene boules into geometries suitable for fast neutron detection. Crystal growth and fabrication of the mixed crystal DPAC-stilbene will be undertaken in this research.