Review of laser produced multi-keV X-ray sources from metallic foils, cylinders with liner, and low density aerogels

Journal Article · Fri Apr 15 04:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4947306· OSTI ID:22599104

Girard, Frédéric ^[1]

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1. CEA, DAM, DIF, F-91297 Arpajon (France)

Experimental results obtained within the last fifteen years on multi-keV X-ray sources irradiated with nanosecond scale pulse duration 3ω laser light at TW power levels by CEA and collaborators are discussed in this review paper. Experiments were carried out on OMEGA and GEKKO XII laser facilities where emitting materials in the 5–10 keV multi-keV energy range are intermediate Z value metals from titanium to germanium. Results focused on conversion efficiency improvement by a factor of 2 when an underdense plasma is created using a laser pre-pulse on a metallic foil, which is then heated by a second laser pulse delayed in time. Metal coated inner surface walls of plastic cylindrical tube ablated by laser beam impacts showed that plasma confinement doubles X-ray emission duration as it gives adequate plasma conditions (electron temperature and density) over a long period of time. Low-density aerogels (doped with metal atoms uniformly distributed throughout their volume or metal oxides) contained in a plastic cylinder have been developed and their results are comparable to gas targets. A hybrid target concept consisting of a thin metal foil placed at the end of a cylinder filled with low density aerogel has emerged as it could collect benefits from pre-exploded thin foils, efficient laser absorption in aerogel, and confinement by cylinder walls. All target geometry performances are relatively close together at a given photon energy and mainly depend on laser irradiation condition optimizations. Results are compared with gas target performances from recent NIF experiments allowing high electron temperatures over large dimension low density plasmas, which are the principal parameters for efficient multi-keV X-ray production.

• OSTI ID: 22599104
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 23; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPARATIVE EVALUATIONS
CYLINDERS
DOPED MATERIALS
ELECTRON DENSITY
ELECTRONS
FOILS
GELS
GERMANIUM
KEV RANGE
LASER RADIATION
LASERS
OXIDES
PLASMA CONFINEMENT
PLASMA DENSITY
PLASTICS
TITANIUM
X RADIATION
X-RAY SOURCES