Investigation of the dynamics of the Z-pinch imploding plasma for a laser-assisted discharge-produced Sn plasma EUV source

• Published in: Journal of Physics D: Applied Physics Vol. 44; no. 14; p. 145203
• Main Authors: Zhu, Q, Yamada, J, Kishi, N, Watanabe, M, Okino, A, Horioka, K, Hotta, E
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 13.04.2011; Institute of Physics
• Subjects: Exact sciences and technology; Laser-plasma interactions; Other confinement methods; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma production and heating; Plasma sources; X-ray, gamma-ray and particle generation; Z-pinches, plasma focus and other pinch devices; Cathode region; Ultraviolet sources; Plasma inertial confinement; Density distribution; Plasma sources; Plasma confinement; Shock waves; Plasma instability; Radiation sources; Tin; Longitudinal pinch; Plasma generation; Electron density; Extreme ultraviolet radiation
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/44/14/145203

Dynamics of the imploding plasma and its relations to the 13.5 nm EUV emissions have been experimentally investigated for a laser-assisted Sn based discharge-produced plasma EUV source. The behaviours and two-dimensional electron density distributions of the EUV-emitting plasma were obtained using the time-resolved shadowgraph and Nomarski interferometric techniques. Observation of the plasma piston in the prepinch phase justified the validity of the zero-dimensional thin-shell model, from which the ion charge state of the prepinch plasma in the cathode region was estimated. The sausage ( m = 0) instability that usually enhances the EUV emission was observed, with the radial electron density distribution that displays a concave shape at the crest of the plasma and a bell shape at the neck; the maximum of the electron density is located at one peak of the concave distribution at the crest instead of the neck. Intense EUV emission was produced by the Z -pinch plasma with the electron density (2.0–3.0) × 10 18  cm −3 . Moreover, the shock waves generated in the anode region can also produce in-band EUV emission with the intensity of 30% of that from the Z-pinch plasma.