Friday, 26 May 2017

Terahertz Time-Domain Spectroscopy for In Situ Monitoring of Ceramic Nuclear Waste Forms

Clark, Braeden M., and S. K. Sundaram. "Terahertz Time-Domain Spectroscopy for In Situ Monitoring of Ceramic Nuclear Waste Forms." Journal of Infrared, Millimeter, and Terahertz Waves 37, no. 10 (2016): 993-1000.

Abstract
The use of terahertz time-domain spectroscopy (THz-TDS) is presented as a non-contact method for in situ monitoring of ceramic waste forms. Single-phase materials of zirconolite (CaZrTi2O7), pyrochlore (Nd2Ti2O7), and hollandite (BaCs0.3Cr2.3Ti5.7O16 and BaCs0.3CrFeAl0.3Ti5.7O16) were characterized. The refractive index and dielectric properties in THz frequencies demonstrate the ability to distinguish between these materials. Differences in processing methods show distinct changes in both the THz-TDS spectra and optical and dielectric properties of these ceramic phases. The temperature dependence of the refractive index and relative permittivity of pyrochlore and zirconolite materials in the range of 25–200 °C is found to follow an exponential increasing trend. This can also be used to monitor the temperature of the ceramic waste forms on storage over extended geological time scales.
... A Teraview TPS 3000 (Teraview, UK) was used to measure the spectra of the samplesfrom 0.1 to 1.2 THz at room temperature in transmission mode. A reference measurementwas made in pure nitrogen prior to the sample measurements. ...
for full paper see https://link.springer.com/article/10.1007/s10762-016-0289-2
for more information about TeraView see http://www.azom.com/equipment-details.aspx?EquipID=4411