Ablation of single-crystalline cesium iodide by extreme ultraviolet capillary-discharge laser

• Main Authors: Wild Jan, Pira Peter, Burian Tomas, Vysin Ludek, Juha Libor, Zelinger Zdenek, Danis Stanislav, Nehasil Vaclav, Rafaj Zdenek, Nevrly Vaclav, Dostal Michal, Bitala Petr, Kudrna Pavel, Tichy Milan, Rocca Jorge J.
• Format: Article
• Language: English
• Published: Sciendo 2020-12-01
• Series: Nukleonika
• Subjects: ablation; csi; desorption; laser; pld; xuv
• Online Access: https://doi.org/10.2478/nuka-2020-0031

Extreme ultraviolet (XUV) capillary-discharge lasers (CDLs) are a suitable source for the efficient, clean ablation of ionic crystals, which are obviously difficult to ablate with conventional, long-wavelength lasers. In the present study, a single crystal of cesium iodide (CsI) was irradiated by multiple, focused 1.5-ns pulses of 46.9-nm radiation delivered from a compact XUV-CDL device operated at either 2-Hz or 3-Hz repetition rates. The ablation rates were determined from the depth of the craters produced by the accumulation of laser pulses. Langmuir probes were used to diagnose the plasma plume produced by the focused XUV-CDL beam. Both the electron density and electron temperature were sufficiently high to confirm that ablation was the key process in the observed CsI removal. Moreover, a CsI thin film on MgO substrate was prepared by XUV pulsed laser deposition; a fraction of the film was detected by X-ray photoelectron spectroscopy.