Keywords and Phrases
Diffusivity measurement technique; Modulated photothermal radiometry; Phothermal radiometry; Thermal characterization; Thermal diffusivity
"This thesis outlines the development of a system used for determining the surface thermal diffusivity of both non-irradiated and irradiated materials. The motivation for this work is to establish a modulated photothermal radiometry (PTR) system on the campus of Missouri University of Science and Technology. One of the main efforts described in this thesis is the design and construction of the physical apparatus. Along the way, it was necessary to perform a detailed sensitivity analysis of the system to determine whether the expected signal emitted from the sample falls within the bounds of detectivity for the HgCdTe (MCT) detector used to measure the infrared (IR) emission of the specimen.
The power of IR radiation from an idealized planar specimen surface was calculated based on the power of the incident laser used to modulate heat flux into the surface. The analysis performed was based on the principles of the radiative heat transfer from the specimen surface and heat conduction within the specimen. Upon comparing the calculated values to those provided by a thermoelectrically cooled HgCdTe detector, it was determined that while a 400 mW laser should produce an emission signal strong enough for the detector to measure, the DC voltage response of a thermoelectrically cooled MCT detector falls below the measurement range of the lock-in amplifier used in the signal path. These finding were used to inform a second stage redesign of the system which incorporates a new laser and liquid nitrogen cooled MCT detector.
This work summarizes the initial design, construction and troubleshooting of an in-house PTR system that helps establish a pathway to a fully complete and working system"--Abstract, page iii.
Graham, Joseph T.
Schlegel, Joshua P.
Alajo, Ayodeji Babatunde
Nuclear Engineering and Radiation Science
M.S. in Nuclear Engineering
U.S. Nuclear Regulatory Commission
Missouri University of Science and Technology
viii, 54 pages
© 2018 Jessica Nicole Seals, All rights reserved.
Thesis - Open Access
Electronic OCLC #
Seals, Jessica Nicole, "Modulated photothermal radiometry: Detector sensitivity study and experimental setup" (2018). Masters Theses. 7833.