Final Report LDRD 04-ERD-019 Development of absolute spectroscopic diagnostics for non-LTE plasmas (open access)

Final Report LDRD 04-ERD-019 Development of absolute spectroscopic diagnostics for non-LTE plasmas

This project sought to further our understanding of non-Local Thermodynamic Equilibrium (NLTE) processes by providing benchmark data to validate computational models. This has been a difficult regime to study in the laboratory, where experimental scales produce strong gradients while interpretation requires well-characterized uniform plasmas. It has also been a difficult regime to simulate, as evidenced by the large discrepancies in predictions of NLTE spectra for fixed plasma properties. Not surprisingly, discrepancies between data and calculations of recombining laser-produced plasmas have been in evidence since the 1980's. The goal here was to obtain data of sufficient accuracy to help resolve these discrepancies and enable better modeling of the NLTE processes that are integral to high-energy density experiments. Advances in target fabrication, diagnostic development and simulation capabilities provided the foundations for this project. Uniform plasmas were to be achieved by using aerogel foams of low enough density ({approx}mg/cm{sup 3}) and thickness ({approx}mm) to be volumetrically heated by a laser. The foams were doped with Ti to provide K- and L-shell emission and recombination spectra during the experiments. A new absolutely calibrated transmission grating spectrometer provided absolute temporal measurements at 18 frequencies, in addition to a CCD image of the time-integrated spectrum. Finally, …
Date: April 19, 2010
Creator: Scott, H. A.
System: The UNT Digital Library
Selected Profiles of Future Technology in Urban Settings: Informational and Behavioral Developments (open access)

Selected Profiles of Future Technology in Urban Settings: Informational and Behavioral Developments

This report is on Selected Profiles of Future Technology in Urban Settings: Informational and Behavioral Developments.
Date: April 19, 1978
Creator: Kornbluh, Marvin
System: The UNT Digital Library