Novel Doped Hg2Br2 As A New High-Performance Scintillator for Nuclear Physics Research

Current COTS scintillation detectors are still not ideal for applications that simultaneously require non-hygroscopicity, high density, fast timing, radiation hardness, cost-effectiveness and with dual gamma-neutron detection capability as in nuclear physics research and other advanced modern scientific research. An alternative solution is thus needed, as called for by the DOE. Brimrose Technology Corporation proposes the development of a new high-performance scintillator that is non-hygroscopic, dual gamma-neutron capable, fast, radiation hard, cost-effective as well as bright and high-density scintillator for nuclear physics research, our novel activator-doped Hg2Br2 crystal. The advantages of this material over CLYC and other COTS scintillators are multifold. Undoped Hg2Br2 is a semiconductor material that can also fluoresce due to its excellent optical properties. Two-inch dia. x 3” length single crystals have been grown in-house at Brimrose for use in LWIR imaging and acousto-optic devices. Recent R&D efforts in our lab have shown that by doping with proper activators, we can enhance the light emission capability of Hg2Br2 in the visible range and transform this crystal material into a great scintillator. Initial results are already very encouraging. We have been able to obtain good, repeatable even after several months, nuclear response of doped-Hg2Br2 as a scintillator, to various gamma energies as well as alpha particles (a well-known indicator of neutron detection, along with the intrinsic property of 99Hg with a capture cross section of 2200 barns), using both commercially available SiPM as well as conventional PMT, along with many highly desirable scintillator properties. All growth/characterization, device fabrication, along with gamma and alpha particle testing will be done at Brimrose whereas dual gamma-neutron detector testing and radiation hardness testing will be done by our subcontractor/partner, the U. Rochester’s OMEGA facility, a DOE Lab with a Neutron source. Phase I work will be to thoroughly evaluate the feasibility of our proposed doped Hg2Br2 scintillator as a practical and reliable versatile scintillator that can address most, if not all the limitations exhibited by current radiation detector materials. Besides our new scintillator with the initial feasibility demonstration, all needed components for a detector system are commercially available. Hence, we can readily roll out a spectrometer prototype in Phase 2 that can be easily tested at any nuclear physics facility. The successful outcome of this Phase 1 research is a new, versatile, high-performance scintillator that can simultaneously address most, if not all, of the limitations of existing COTS scintillators. The proposed material is non hygroscopic, has fast timing, is dual gamma- neutron capable, is radiation hard and cost effective. There is tremendous potential for widespread commercialization of the materials and devices that will be developed during this program. Additionally, at this time, high performance Hg2X2 (X=Br, Cl) scintillator materials are not available commercially. We hope to develop a domestic source for this material as an outcome of this research. We feel that our expertise in commercialization can make this a reality.