Plasma dynamics of a confined extreme ultraviolet light source

Abstract

Laser plasmas were generated by ablation of aluminum targets via a Nd:YAG glass laser, of pulse energy 0.8 J, and duration 15 ns (full width at half maximum) at the fundamental wavelength (1.064 μm). Emission lines in the wavelength range of 27–32 nm (45–37.8 eV) were mapped over a spatial range extending out 1.8 mm from the target surface and for a temporal range of 42 ns after the termination of the laser pulse. Two targets were utilized: a planar surface and a rectangular cavity. The latter was composed of a rectangular shaped cavity of depth 3 mm and height 1.2 mm, cut into an aluminum massive. An irradiance of Ip∼1011 W/cm2 was delivered to both targets and the confining influence of the rectangular cavity upon plasma formation and expansion was studied. Diagnostics of the emitted spectra reveal the unique dynamics of restricted plasma plume expansion, which results in plasma-surface collisions and subsequent plasma rebound within the cavity. These effects give rise to strong enhancement of both continuum and line emission in the contained plasma plume. These enhancements are especially evident for the more highly charged ions. Superior emission from plasma-surface collisions are associated with “forced recombination” during early time scales, while enhanced emission at later stages are associated with plasma plume component rebound and collision.

Dynamics of laser-blow-off induced Li plume in confined geometry

“…The optical emission characteristics and the shock wave dynamics in laser induced plasmas have been investigated using spectroscopy, photography, shadowgraphy, and interferometric techniques in gases, liquids, and geometrical shapes. [18][19][20][21][22][23][24][25][26][27] Zeng et al investigated laser produced plasma confined in micromachined fused silica cavities. 22 Bhupesh et al reported a comparative study of shock wave dynamics and optical emission of titanium plasma in the liquid and gas ambients.…”

“…14 Yeates et al reported superior plasma emission from the plasma-surface collisions in rectangular cavity and attributed this to forced recombination. [24][25][26] Investigation of the optical emission and plume dynamics of LBO plasma in different gas ambients have been reported by several researchers. 7,8,28 However, not much work has been done on the investigation of shock wave dynamics in LBO plasma using shadowgraph imaging except a few using ultrafast laser pulses.…”

Effects of excitation laser wavelength on Ly-α and He-α line emission from nitrogen plasmas

“…1-5 However, synchrotron use is severely constrained by cost and limited accessibility and requires long term planning and transportation of samples, making this option impractical for most researchers. Potential laboratory-scale WW-transmission x-ray microscopy (TXM) sources are soft x-ray lasers, 6,7 laser-produced plasma (LPP) sources, [8][9][10][11] and higher harmonics from laser heated targets. 12,13 WW sources based on LPPs have several advantages over other sources that include power scalability through the tuning of laser parameters, good dose control, flexibility in dimensions, spatial stability, minimum heat load, and a large solid angle of collection.…”

Light erosive optical discharges investigation. I. Investigation of radially confined light erosive pulsed optical discharges

“…Как известно, исследование импульсных течений га-зоразрядных процессов представляет значительный интерес для фун-даментальных и прикладных исследований [1]. Радиально ограни-ченные лазерно-индуцированные потоки используются в таких при-ложениях, как лазерное сверление глубоких отверстий [2], лазерная генерация тяги [3][4][5], увеличение выхода ВУФ-, ЭУФ-и МР-излу-чения [6][7][8], генерация ударных волн и инжекция плазмы, лазерное инициирование капиллярного разряда [9], ускорение тел лазерной волной детонации в канале с испаряющейся стенкой [10] и др.…”