Calibration-free real-time organic film thickness monitoring technique by reflected X-Ray fluorescence and compton scattering measurement

• Published in: Nuclear engineering and technology Vol. 53; no. 4; pp. 1297 - 1303
• Main Authors: Park, Junghwan, Choi, Yong Suk, Kim, Junhyuck, Lee, Jeongmook, Kim, Tae Jun, Youn, Young-Sang, Lim, Sang Ho, Kim, Jong-Yun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-04-2021; Elsevier; 한국원자력학회
• Subjects: Compton scattering; Organic film; Thickness; X-ray fluorescence; X-ray radiation; 원자력공학; Thickness; Compton scattering; X-ray radiation; X-ray fluorescence; Organic film
• ISSN: 1738-5733; 2234-358X
• DOI: 10.1016/j.net.2020.09.018

Most thickness measurement techniques using X-ray radiation are unsuitable in field processes involving fast-moving organic films. Herein, we propose a Compton scattering X-ray radiation method, which probes the light elements in organic materials, and a new simple, non-destructive, and non-contact calibration-free real-time film thickness measurement technique by setting up a bench-top X-ray thickness measurement system simulating a field process dealing with thin flexible organic films. The use of X-ray fluorescence and Compton scattering X-ray radiation reflectance signals from films in close contact with a roller produced accurate thickness measurements. In a high-thickness range, the contribution of X-ray fluorescence is negligible, whereas that of Compton scattering is negligible in a low-thickness range. X-ray fluorescence and Compton scattering show good correlations with the organic film thickness (R2 = 0.997 and 0.999 for X-ray fluorescence and Compton scattering, respectively, in the thickness range 0–0.5 mm). Although the sensitivity of X-ray fluorescence is approximately 4.6 times higher than that of Compton scattering, Compton scattering signals are useful for thick films (e.g., thicker than ca. 1–5 mm under our present experiment conditions). Thus, successful calibration-free thickness monitoring is possible for fast-moving films, as demonstrated in our experiments.