Figure 3
From: A novel nanometric DNA thin film as a sensor for alpha radiation
Optical characteristics of the DXL upon radiation exposure.
(a) Schematic diagram illustrating the experimental setup used for the evaluation of optical characteristics of the DXL upon exposure to radiation from 241Am alpha particle source. The reflectance probe was placed at a fixed distance of 1 cm from PG and the reflected light signal was measured using a spectrometer and silicon photo detector. The reflectance probe tip consisted of six illuminating fibers (a1 to a6) and one reflected light fiber at the center (b) as shown in right bottom corner. The ray diagram of incident light and reflected light from PG and the DXL is shown in the upper left corner where 1 (blue arrow) corresponds to incident light and reflected light from the top of PG and 2 (green) corresponds to the reflected light from the bottom surface of PG and the DXL film. (b) The reference spectrograph for air, glass and PG. (c) The change in reflected light intensity controlled by exposure time at various distances d = 1, 2 and 5 cm. The experimental error is estimated to be within ±5%. (d) The change in reflected light intensity as measured by silicon photo detector at d = 1 cm for texp up to 15 min.
