ADVANCED MANUFACTURING OF MICRO POCKET FISSION DETECTOR (MPFD)

A need exists for advanced instrumentation neutron-flux mapping with in the reactor-core for the Transient REActor Test (TREAT) facility and Advanced Test Reactor (ATR) experiments supporting advanced nuclear material testing. In addition, many U.S. research reactors and industrial power nuclear-reactors would benefit from in-core neutron-flux monitoring. Here it is proposed to research advanced Micro-Pocket Fission Detector (MPFD) designs fabricated with alternative materials with VLSI methods for commercial production of the MPFD technology. A challenge for the project PI is to design a low-cost manufacturing method that allows for mass-production of these unique miniaturized fission chambers. The use of VLSI methods for MPFDs is unique to this project, and has not yet been conducted by any group nor for any prior or current project. The final deliverable for this project is a commercial-grade MPFD (C-MPFD) that has been designed and manufactured with commercialization as the primary focus. A secondary deliverable is a packaged C-MPFD with readout electronics for use with nuclear reactor instrumentation. The specific aims of this project are (1) to develop low-cost, easily-produced (VLSI techniques) variants of C-MPFDs in support of ongoing and future DOE-sponsored projects and (2) to understand better the signal pathway by a combination of testing and modeling. It is proposed to develop cost-effective and easily-produced variants of C-MPFDs and to study, in detail, their response, starting with the initiating (fission) event and ending with the discernible pulse and count. To address these issues, it is proposed to model, design, manufacture, and characterize C-MFPDs from alternative materials that can be mass-produced at low cost. A two-phase plan is proposed to accomplish this effort. In Phase I, C-MPFD fabrication methodology, specifically applying VLSI fabrication techniques and micromachining these hard ceramic- materials, raw-material supply-chain trade study, and C-MPFD packaging for wide-range temperature operation will be investigated. In Phase II, further work will be pursued to fully develop the C-MPFD and reduce its production-cost point, develop the readout electronics for the C-MPFD. The scientific and commercial impact from the proposed research is expected to be significant. The results from this project will directly impact the quality of nuclear-reactor materials research. Successful completion of this project will deliver compact neutron-flux detectors capable of real-time in-core neutron-flux measurements at high-temperature, e.g., >100C, and high-dose radiation environment. Inclusively, frontend electronics will be developed to handle the signal amplification of the C-MPFD under high-temperature and radiation-dose environments, which has yet to be accomplished. Micro-pocket fission detectors are already well known within the DOE nuclear engineering community, with their use is beginning to play a significant role in many currently- funded projects, e.g., TREAT and DoD nuclear-power reactors. The commercial availability of these innovative sensors will accelerate the advancement of nuclear material testing; and hence, improving the quality of irradiation test programs. The outcome of this proposed work will be a design for devices that are inexpensive and easy to build in mass, and the impact will be the potential rapid deployment of these devices to the DOE and related communities.