A. E. Gorodetsky, A. V. Markin, V. L. Bukhovets, T. V. Rybkina, R. Kh. Zalavutdinov, A. P. Zakharov, E. E. Mukhin, A. G. Razdobarin, “Near surface modification of R-sapphire exposed to long term RF hydrogen-neon plasma”, Pisma v Zhurnal Tekhnicheskoi Fiziki, 2024, Volume 50, Issue 21,Pages <nobr>15

Near surface modification of R-sapphire exposed to long term RF hydrogen-neon plasma

A. E. Gorodetsky^a, A. V. Markin^a, V. L. Bukhovets^a, T. V. Rybkina^a, R. Kh. Zalavutdinov^a, A. P. Zakharov^a, E. E. Mukhin^b, A. G. Razdobarin^b

^a Institute of Physical Chemistry and Electro Chemistry, Russian Academy of Sciences, Moscow, Russia
^b Ioffe Institute, St. Petersburg, Russia

Abstract: Samples of R-sapphire were exposed to long term RF hydrogen-neon plasma. Modification of near-surface layers was studied by XRD and XPS, and optical changes were assessed by spectrophotometry. After removing 270 nm thick layer the internal stresses remained at an initial value, but in the layer that probing by XRD individual blocks turned around and shifted from the Bragg reflection. XPS shows that aluminum is still an Al$_2$O$_3$ compound. Light transmission in the wavelength range 400–1000 nm remained unchanged which makes it possible to use sapphire as a protection window for optical diagnostics in fusion facilities.

Keywords: sapphire, RF discharge, hydrogen, neon, structure surface layer, light transmission, iter.

Received: 10.06.2024
Revised: 08.07.2024
Accepted: 08.07.2024

DOI: 10.61011/PJTF.2024.21.58952.20016