A Low Level Tritium Monitor Based on a Multi-Phase Scintillator Material

41068 November 20, 1996 Aerodyne Research, Inc. Scintillation phosphors, materials commonly used in particle detectors, emit a photon of light when struck by a subatomic particle, and the light flashes are counted as an indicator of atomic decay. This project will explore the feasibility of monitoring tritium by using an ultra low density (milligrams per cubic centimeter range) silica aerogel as a carrier of a scintillation phosphor. The phosphor will be perfused into the aerogel in the gas phase, where it will be adsorbed onto the existing silica structure of the aerogel. Because the low density aerogel is highly permeable to gases, every tritium atom in the gas will be close to a region of space containing scintillation phosphor. In this way, the problem of absorption by the ambient air, of the low energy beta particles emitted by tritium is avoided. The novel aspect of this research is the multi-phase (aerogel/ phosphor) scintillator material; in other respects, the tritium monitor is based on the well established principles of scintillation counting, using standard photomultiplier tubes and pulse counting circuitry. Naphthalene will be used as a typical aromatic scintillation phosphor, used in conventional scintillation counters. The project will determine how much scintillation phosphor can be put into the foam, how well it works, and what kind works best. Commercial Applications and Other Benefits as described by the awardee: The tritium monitor will be more sensitive, rugged and reliable than existing monitors based on other techniques (such as ionization chambers). It will have a commercial market wherever tritium must be monitored, and may also be applicable to the real-time monitoring of radon, a well known health hazard in buildings.