Micro-fluidics and integrated optics glass sensor for in-line micro-probing of nuclear samples

• Published in: IEEE transactions on nuclear science 2012-08, Vol.59 (4)
• Main Authors: Schimpf, A., Bucci, D., Broquin, J.E., Canto, F., Magnaldo, A., Couston, L.
• Format: Article
• Language: English
• Subjects: ABSORPTION; BOROSILICATE GLASS; CONTROL; FEASIBILITY STUDIES; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; INTERFEROMETERS; ION EXCHANGE; MINIATURIZATION; NUCLEAR FUEL CYCLE AND FUEL MATERIALS; REFRACTIVE INDEX; REPROCESSING; SENSITIVITY; SENSORS; SPENT FUELS; VOLUME
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2012.2205704

We study the miniaturization of Thermal Lens Spectrometry (TLS) towards Lab-on-chip integration in order to reduce the volume of fluid assays in nuclear process control. TLS is of great interest in this context since it combines the advantages of optical detection methods with an inherent suitability for small-scale samples. After validating the experimental principle in a classical thermal lens crossed-beam setup, we show the integration of a Young-interferometer with a microcapillary on a glass substrate, reducing the necessary sample size to 400 nl. The interferometer translates the photo-thermally induced refractive index change in the fluid to a phase shift of the fringe pattern, which can then be detected by a camera. Measurements of Co(II) in ethanol yield a detection limit of c = 5 x 10{sup -4} M for the crossed-beam setup and c = 6 x 10{sup -3} M for the integrated sensor. At an interaction length of 10 m, it detects a minimum absorbance of K = 1.2 x 10{sup -4} in a probed volume of 14 pl. (authors)