Collection of solid and gaseous samples to diagnose inertial confinement fusion implosions.
Collection of representative samples of debris following inertial confinement fusion implosions in order to diagnose implosion conditions and efficacy is a challenging endeavor because of the unique conditions within the target chamber such as unconverted laser light, intense pulse of x-rays, physical chunks of debris, and other ablative effects. We present collection of gas samples following an implosion for the first time. High collection fractions for noble gases were achieved. We also present collection of solid debris samples on flat plate collectors. Geometrical collection efficiencies for Au hohlraum material were achieved and collection of capsule debris (Be and Cu) was also observed. Asymmetric debris distributions were observed for Au and Be samples. Collection of Be capsule debris was higher for solid collectors viewing the capsule through the laser entrance hole in the hohlraum than for solid collectors viewing the capsule around the waist of the hohlraum. Collection of Au hohlraum material showed the opposite pattern: more Au debris was collected around the waist than through the laser entrance hole. The solid debris collectors were not optimized for minimal Cu backgrounds, which limited the conclusions about the symmetry of the Cu debris. The quality of the data limited conclusions on chemical fractionation effects within the burning, expanding, and then cooling plasma.
Trace analysis for microelectronically relevant heavy metals in high-purity titanium with isotope dilution mass spectrometry
Because titanium is increasingly used in microelectronic devices, a method of isotope dilution mass spectroscopy (IDMS) has been developed for the reliable determination of traces of relevant heavy metals (U, Th, Cu, Pb, Cd, Cr, Ni, and Fe) in high-purity titanium primary materials. The measurements of isotope ratios were carried out with a thermal ionization quadrupole mass spectrometer using positive thermal ions formed by a single- or double-filament ion source, except for thorium where an inductively coupled plasma mass spectrometer was applied. Different separation techniques (ion exchange chromatography, extraction, electrolytic deposition, co-precipitation) were used for the trace/matrix separation and the element-specific isolation of the trace elements to be determined
The classical roots of poststructuralism: Lacan, Derrida, and Foucault
This paper argues that French poststructuralist theory does not represent a movement antithetical to Classics and the Classical Tradition, but should be read as its extension. Major recurring themes of poststructuralist thought are articulated at the beginning of the 1960’s in Lacan’s commentaries on Sophocles’Antigone and Plato’sSymposium. Derrida’s reading of thePhaedrus as well as his citation of the Platonic tradition in his dispute with Foucault over the latter’sHistoire de la folie further confirm the importance of the Hellenic tradition to poststructuralism’s engagement with occidental philosophy. Finally, Foucault’s late turn to Stoicism and the philosophers of the Roman imperial period can be seen as a response to and criticism of the positions established by Lacan and Derrida. The Classics are not only relevant to understanding poststructuralist theory and philosophy, but actually define the terms of its debates.