Efficient multi-keV x-ray sources from Ti-doped aerogel targets

• Published in: AIP conference proceedings Vol. 730; no. 1; pp. 223 - 232
• Main Authors: Fournier, K B, Constantin, C, Gregori, G, Miller, M C, Back, C A, Suter, L J, Davis, J, Grun, J
• Format: Journal Article
• Language: English
• Published: United States 01.01.2004
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALUMINIUM; COMPRESSION; CRYSTALS; DOPED MATERIALS; HEATING; IONS; K SHELL; KEV RANGE; LASERS; PHOTON EMISSION; PLASMA PRODUCTION; STREAK CAMERAS; TITANIUM; X RADIATION; X-RAY SOURCES
• ISBN: 0735402116; 9780735402119
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.1824873

We have measured the production of hv 4.7 keV x-rays from low-density Ti-doped aerogel ( 3 mg/cc) targets at the OMEGA laser facility (University of Rochester), with the goal of maximizing x-ray output. Forty OMEGA beams (L = 0.351 mum) illuminated the two cylindrical faces of the target with a total power that ranged from 7 to 14 TW. The laser fully ionizes the target (ne/ncrit 0.1), and a laser-bleaching wave excites, supersonically, the high-Z emitter ions in the sample. Heating in the target was imaged with gated x-ray framing cameras and an x-ray streak camera. Ti K-shell x-ray emission was spectrally resolved with a two-channel crystal spectrometer and also with a set of filtered aluminum x-ray diodes, both instruments provide absolute measurement of the multi-keV x-ray emission. We find between 40 - 260 J of output with 4.67 hv 5.0 keV. Radiation-hydrodynamic calculations predict late time enhancement of the x-ray power due first to axial stagnation of the heating waves, then, ablatively-driven radial compression from the target walls.