X-Ray Sensing by Mercury Iodide Poly-Vinyl Alcohol Composite

Abstract

Technology has modified nearly every aspect of modern life and digital devices have made an important place in every field. In medical field also the digital X-ray applications have contributed a lot. The most important component of digital imaging system is X-Ray sensor. Solid state sensor materials are used as X-ray sensors, like lead iodide, Zinc Sulphide, Titanium dioxide and Mercuric idodide, etc. Mercury Iodide has some favourable properties which make it most suitable material for X-Ray sensor. In present study, polymer composites of Mercury Iodide were prepared using polyvinyl Alcohol (PVA) at room temperature. Studies revealed that Mercury Iodide - PVA sheets show a stable detection of X-rays for all concentrations and the value of (Imax-Imin) increases with increase in the concentration of Mercury iodide to 32 %, and after concentration of 61 % value of (Imax-Imin) starts decreasing. An optimized range of concentration is worked out (32 % to 61%) at which the maximum value of photocurrent is obtained. X-ray switching studies conducted on these sheets show low rise and fall time making the material good for imaging applications. For the concentration of 32.2 % concentration rise time was recorded as 0.99 for a pulse of 2s and more.