A Gas Density Detector Utilizing Uranium Doped Scintillating Ceramic Microchannels

This paper reports on a contactless gas density sensor, which utilizes an injection molded cast ceramic that is doped with uranyl acetate nanoparticles. This cast micro channel provides a robust, on chip beta particle (fast electron) source. High-energy sources with tunable particle fluxes can be cast at room temperature with protective polymer coatings for flux tuning. A room temperature cured polymer scintillating resin is patterned on a glass substrate, which is bonded to the radioactive microchannel. This detector produces pulses of light when beta particles emitted from the microchannel impinge on the scintillator. The detected pulses of lights caused by the electron-scintillator interaction are attenuated by the presence of gas in the microchannel; more and larger gas molecules block more beta particles. This allows real time measurement of gas density (and therefore pressure, or percentage gas impurity) flowing through a channel, with no sensor in direct contact to impede or change the rate gas flow. The radioactive microchannel is coated to prevent contamination of the flowing gas, and to block lateral beta emission.