creators_name: Mongkolnavin, R.
creators_name: Ngamrungroj, D.
creators_name: Leeviriyalard, C.
creators_name: Wong, C. S.
type: article
datestamp: 2007-11-03 17:36:23
lastmod: 2008-08-26 04:08:41
metadata_visibility: show
corp_creators: Chulalongkorn University, Faculty of Science, Dept. of Physics
corp_creators: University of Malaya, Faculty of Science, Dept. of Physics
title: Effect of X-ray from a small plasma focus on colorless synthetic corundum
ispublished: pub
subjects: Q
full_text_status: none
keywords: Plasma focus application; x-rays, Corundum, physics
abstract: 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. 
date: 2004
date_type: published
publication: Jurnal Fizik Malaysia
volume: 25
number: 3 & 4
publisher: Malaysian Institute of Physics (IFM)
pagerange: 87-91
refereed: TRUE
issn: 0128-0333 
official_url: http://eprints.ictp.it/222/; http://eprints.ictp.it/222/01/JFMv25-87.pdf
related_url_url: http://eprints.ictp.it/222/01/JFMv25-87.pdf
referencetext: [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).
citation: Mongkolnavin, R. and Ngamrungroj, D. and Leeviriyalard, C. and Wong, C. S. (2004) Effect of X-ray from a small plasma focus on colorless synthetic corundum. Jurnal Fizik Malaysia, 25 (3 & 4). pp. 87-91. ISSN 0128-0333