Details

Autor(en) / Beteiligte

• Perez, F
• Kay, J J
• Patterson, J R
• Kane, J
• Villette, B
• Girard, F
• Reverdin, C
• May, M
• Emig, J
• Sorce, C

Titel

Efficient laser-induced 6-8 keV x-ray production from iron oxide aerogel and foil-lined cavity targets

Ist Teil von

• Physics of plasmas, 2012-08, Vol.19 (8)

Ort / Verlag

United States: American Institute of Physics (AIP)

Erscheinungsjahr

2012

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The performance of new iron-based laser-driven x-ray sources has been tested at the OMEGA laser facility for production of x rays in the 6.5-8.5 keV range. Two types of targets were experimentally investigated: low-density iron oxide aerogels (density 6-16 mg/cm3) and stainless steel foil-lined cavity targets (steel thickness 1-5 mu m). The targets were irradiated by 40 beams of the OMEGA laser (500 J/beam, 1 ns pulse, wavelength 351 nm). All targets showed good coupling with the laser, with <5% of the incident laser light backscattered by the resulting plasma in all cases (typically <2.5%). The aerogel targets produced Te=2 to 3 keV, ne=0.12-0.2 critical density plasmas yielding a 40%-60% laser-to-x-ray total conversion efficiency (CE) (1.2%-3% in the Fe K-shell range). The foil cavity targets produced Te similar to 2 keV, ne similar to 0.15 critical density plasmas yielding a 60%-75% conversion efficiency (1.6%-2.2% in the Fe K-shell range). Time-resolved images illustrate that the volumetric heating of low-density aerogels allow them to emit a higher K-shell x-ray yield even though they contain fewer Fe atoms. However, their challenging fabrication process leads to a larger shot-to-shot variation than cavity targets.