987 12 archive 2 disk0/00/00/09/87 2007-11-03 17:36:23 2008-08-26 04:08:41 2007-11-03 17:36:23 article show Mongkolnavin R. Ngamrungroj D. Leeviriyalard C. Wong C. S. Chulalongkorn University, Faculty of Science, Dept. of Physics University of Malaya, Faculty of Science, Dept. of Physics pub Q none Plasma focus application; x-rays, Corundum, physics A preliminary investigation on effect of X-ray on colorless synthetic corundum has been carried out. The X- ay used was generated from a small 3 kJ UNU/ICTP Plasma Focus device. The X-ray produced by the focusing plasma was measured by using four channels PIN diode spectrometer. The spectral content of the X-ray and the plasma electron temperature were obtained by a ratio method. The electron temperature was deduced to be 1.9 keV. The color of the corundum changed to yellow-brown after an exposure with the X-ray. The intensity of the color varied with the number of focusing and non-focusing shot applied to the samples. UV-VIS-NIR Spectrometer was used to test the photo-absorption of the treated corundum. The experimental results show that the color change is not caused by a known Rayleigh’s scattering process. This color change is non-permanent and can be reverted to its initial state by thermal annealing process. 2004 published Jurnal Fizik Malaysia 25 3 & 4 Malaysian Institute of Physics (IFM) 87-91 TRUE 0128-0333 http://eprints.ictp.it/222/; http://eprints.ictp.it/222/01/JFMv25-87.pdf http://eprints.ictp.it/222/01/JFMv25-87.pdf [1] Wong C.S., Jurnal Fizik Malaysia, 23 (1-4), 4 (2002). [2] Wong C.S., Moo S.P., Singh J. Singh, P. Choi, C. Dumitrescu-Zoita and Silawatshananai, Malaysian Journal of Science 17(B)109 (1996). [3] Lee S., Tan B.C., Wong C.S. and Chew A. C., Laser and Plasma Technology, World Scientific Publishing Co. Ltd. (1985). [4] Mather J.W., Phys. Fluids Suppl., 7, 28 (1964). [5] Hager T., Temperature Treatment of Natural Corundum, Gemstone Research, Institute of Geosciences, Johannes Gutenberg University (2001).