Commercial ALD Process for Elimination of Memory Effects in Xe Beta Cells

There is a need to improve the monitoring techniques for radioactive xenon (Xe) in the atmosphere, so that clandestine nuclear test explosions can be confirmed. The equipment used for the detection of radioactive Xe gas incorporates plastic scintillators, which unfortunately trap the Xe gas during operation. The result is a residual Xe activity in the detector that affects subsequent measurements, leading to an elevated system detection limit, referred to as the “Memory Effect”. RMD proposes to address this challenge by applying a Xe gas diffusion barrier coating to the surface of the plastic scintillator cell to prevent the diffusion of the radioactive Xenon gas. During Phase I, Atomic Layer Deposition (ALD) of highly transparent aluminum oxide (Al2O3) films will be applied as a Xe-barrier coating on the plastic scintillator surface. These coatings can be applied at low temperatures without affecting the properties of the plastic scintillator such as energy resolution and light collection efficiency. These coatings are robust and pinhole free coatings that can be deposited on 3 dimensional surfaces.