Thompson Jeroen W, Burdette Kevin E, Inrig Elizabeth L, Dewitt Regina, Mistry Rajesh, Rink W Jack, Boreham Douglas R
Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main St West, Hamilton, ON, Canada L9H 6L6.
Radiat Prot Dosimetry. 2010 Sep;141(1):1-9. doi: 10.1093/rpd/ncq143. Epub 2010 May 6.
Gypsum wallboard (drywall) represents an attractive target for retrospective dosimetry by optically stimulated luminescence (OSL) in the event of a radiological accident or malicious use of nuclear material. In this study, wallboard is shown to display a radiation-induced luminescence signal (RIS) as well as a natural background signal (NS), which is comparable in intensity to the RIS. Excitation and emission spectra show that maximum luminescence intensity is obtained for stimulation with blue light-emitting diodes (470 nm) and for detection in the ultraviolet region (290-370 nm). It is necessary to decrease the optical stimulation power dramatically in order to adequately separate the RIS from the interfering background signal. The necessary protocols are developed for accurately measuring the absorbed dose as low as 500 mGy and demonstrate that the RIS decays logarithmically with storage time, with complete erasure expected within 1-4 d.
