Nondestructive imaging with mercuric iodide thick film x-ray detectors

Autor: Evgenie Meerson, Gary Virshup, Robert A. Street, Yehezkel Saado, Edward J. Seppi, A. Zuck, L. Partain, Haim Hermon, George Zentai, Steve E. Ready, Eliezer Shtekel, Benjamin Reisman, Raisa Pavlyuchkova, Michael M. Schieber, Alexander I. Vilensky, Michael Lukach, Leonid Melekhov
Rok vydání: 2001
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.434200
Popis: Polycrystalline mercuric iodide (HgI2) photoconductor material was directly deposited on flat panel amorphous silicon (a-Si) thin film transistor (TFT) pixel arrays in order to test their application as direct x-ray conversion detectors. The 4' x 4' and 2' x 2' detector plates were fabricated either by Physical Vapor Deposition (PVD) or the Screen-Print (SP) method. Although developed for medical radiological imaging, they can also be used for nondestructive test imaging. The present HgI2 arrays have 100 μm x 100 μm pixels on the 2' x 2' detector and 139μm x 139μm on the 4' x 4' imager. The initial results are very promising and show high x-ray sensitivity and low leakage current. The advantage of these detectors is that they can be directly deposited on the pixellated arrays containing the TFTs and other electronic read out circuits and can be fabricated in large sizes. These polycrystalline PVD-HgI 2 thick film detectors have now been fabricated up to 1,800μm thick, which makes them also useful for higher-energy X-ray applications. Imaging results obtained by both PVD- and SP-HgI 2 will be shown. The effect of the crystallite size on the imaging properties will be demonstrated and the difference in sensitivity applying positive or negative bias on the top electrode will be discussed. Comparison of x-ray sensitivity to other photoconductor materials such a-Se and PbI 2 will also be presented.
Databáze: OpenAIRE