X-ray enhancement in a nanohole target irradiated by intense ultrashort laser pulses

Journal Article · Tue Mar 01 04:00:00 EST 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3554407· OSTI ID:21538136

Chakravarty, U; Arora, V; Chakera, J A; Naik, P A; Srivastava, H; Tiwari, P; Srivastava, A; Gupta, P D ^[1]

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1. Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

In this paper, we present a comparative study of the laser energy absorption, soft x-ray emission (in the water window region: 2.3-4.4 nm) and hard x-ray emission (in the 2-20 keV range) from planar aluminum and nanohole alumina of 40 nm average diameter, when irradiated by Ti:sapphire laser pulses. The laser pulse duration was varied from 45 to 500 fs, and the focused intensity on the target ranged from {approx}3 x 10{sup 16} W/cm{sup 2} to 3x10{sup 17} W/cm{sup 2}. The x-ray yield enhancement from the nanoholes shows an increased coupling of the laser energy to the target. The effect of laser pulse duration on the x-ray emission was also studied, where a resonance like phenomenon was observed. The laser energy absorption measurements in the nanoholes showed a marginal enhancement in absorption as compared to planar Al. The integrated keV x-ray yield, from nanohole alumina and planar Al, at an intensity of 3 x 10{sup 17} W/cm{sup 2}, was 25 and 3.5 {mu}J, respectively. The results can be explained by considering the hydrodynamic expansion of the laser irradiated structure and field enhancement in the nanoholes.

• OSTI ID: 21538136
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 109; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CORUNDUM
CYCLIZATION
DISTANCE
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
ENERGY ABSORPTION
ENERGY RANGE
EXPANSION
HARD X RADIATION
IONIZING RADIATIONS
KEV RANGE
LASER RADIATION
MINERALS
MUTATIONS
NANOSTRUCTURES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PULSES
RADIATIONS
SAPPHIRE
SOFT X RADIATION
SORPTION
SPECTRA
SPONTANEOUS MUTATIONS
X RADIATION
X-RAY SPECTRA