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in creator/contributor: "Fournier, K."  
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Short Pulse Laser Absorption and Energy Partition at Relativistic Laser Intensities

Description: We have performed experiments at the COMET and Calisto short pulse laser facilities to make the first comprehensive measurements of the laser absorption and energy partition in solid targets heated with an ultrashort laser pulse focused to relativistic laser intensities (>10 10{sup 17} W/cm{sup 2}). The measurements show an exceedingly high absorption for P polarized laser-target interactions above 10{sup 19} W/cm{sup 2}. Additionally, the hot electron population is observed to markedly incr… more
Date: February 27, 2007
Creator: Shepherd, R.; Chen, H.; Ping, Y.; Dyer, G.; Wilks, S.; Chung, H. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Efficient Multi-keV X-ray Sources from Ti-doped Aerogel Targets

Description: We have measured the production of h{nu} {ge} 4.5 keV x-rays from low-density Ti-doped aerogel targets at the OMEGA laser facility (University of Rochester). The doped-foam density was {approx} 3 mg/cc. Forty beams of the OMEGA laser ({lambda}{sub L} = 0.351 {micro}m) illuminated the two cylindrical faces of the target with a total power that ranged from 7 to 14 TW. The laser interaction fully ionizes the target (n{sub e}/n{sub crit} {ge} 0.1), and allows the laser-bleaching wave to excite, sup… more
Date: November 21, 2003
Creator: Satcher, J.; Fournier, K.; Suter, L.; Davis, J.; Back, C.; Grun, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Efficient Multi-keV X-Ray Sources from Ti-Doped Aerogel Targets

Description: We have measured the production of hv {approx} 4.7 keV x-rays from low-density Ti-doped aerogel ({rho} {approx} 3 mg/cc) targets at the OMEGA laser facility (University of Rochester), with the goal of maximizing x-ray output. Forty OMEGA beams ({lambda}{sub L} = 0.351 {micro}m) 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 (n{sub e}/n{sub crit} {le} 0.1), and a laser-bleaching wave excites, supersonically, … more
Date: April 9, 2004
Creator: Fournier, K.; Constantin, C.; Gregori, G.; Miller, M.; Back, C.; Suter, L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Observation of anomalous Iron Ion Charge Distribution in FTU

Description: Iron coming from the poloidal limiter or the stainless steel vessel is an important intrinsic impurity in the FTU tokamak discharges, and X-ray and VUV spectroscopy provide useful information about the impurity behavior. The iron ion charge state distribution, as usual for tokamaks, is analyzed assuming a collisional radiative model and an anomalous perpendicular diffusion. In our experiment the iron ionization level depends, as it is expected, on central electron temperature (fig. 1), but the … more
Date: November 14, 2003
Creator: Finkenthal, M.; May, M.; Pacella, D.; Leigheb, M.; Zagorski, R.; Mattioli, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Measuring the ionization balance of gold in a low-density plasma of importance to ICF

Description: Charge state distributions (CSDs) have been determined in low density ({approx}10 {sup 12} cm{sup -3}) gold plasmas having either a monoenergetic beam (E{sub Beam} = 2.66, 3.53 and 4.54 keV) or experimentally simulated thermal electron distributions (T{sub e} = 2.0, 2.5 and 3.0 keV). These plasmas were created in the Livermore electron beam ion traps EBIT-I and EBIT-II. Line emission and radiative recombination features of Ni to Kr-like gold ions were recorded in the x-ray region with a crystal… more
Date: May 3, 2004
Creator: May, M.; Beiersdorfer, P.; Schneider, M.; Terracol, S.; Wong, K.; Fournier, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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X-ray Spectroscopy with Elliptical Crystals and Face-On Framing Cameras

Description: X-ray spectrometers using elliptically bent crystals have desirable properties for applications requiring broad spectral coverage, good spectral resolution, and minimized source broadening. Previous work used custom-positioned film or microchannel plate detectors. They find it is also useful and cost-effective to field elliptical crystals in existing snouts on the face-on gated microchannel plate framing cameras commonly used at many facilities. they numerically explored the full design space (… more
Date: April 16, 2004
Creator: Heeter, R.; Emig, J.; Fournier, K.; Hansen, S.; May, M. & Young, B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Estimates if population inversion for deep-UV transitions in Kr-like Y,Zr,Nb and Mo in a high-current reflex discharge

Description: Kr-like ions are good candidates for FUV lasing since they can be produced in plasmas quite easily. We present results from a spectroscopic investigation of Y IV emission from a high current density, cold cathode reflex discharge. The Y II to Y V emission is recorded in the 200-3000 {angstrom} range using photometrically calibrated spectrometers, while the emission of trace aluminum ions serves for plasma diagnostics. The intensities of the Y IV 4d - 5p and 5s - 5p transitions strongly increase… more
Date: July 6, 1999
Creator: Finkenthal, M.; May, M. J.; Fournier, K.; Goldstein, W. H.; Shlyaptsev, V. N.; Soukhanovskii, V. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Impurity transport studies of intrinsic Mo and injected Ge in high temperature ECRH heated FTU tokamak plasmas

Description: FTU plasmas reached a peak electron temperature up to 11 keV with ECRH heating during the current ramp up phase. For these plasmas X-ray emission of highly ionized molybdenum, the dominant intrinsic impurity, are presented in section II, and VUV spectra of injected germanium are presented in section III. In section IV the conclusions are discussed.
Date: June 1, 1999
Creator: Bracco, F.; Crisanti, M.; Finkenthal, M.; Fournier, K.; Gabellieri, G.; Granucci, G. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Use of Lasers to Study the Impact of Fractionation and Condensation on the Toxicity of Nuclear Weapon Fallout

Description: An experimental concept has been developed to collect data to aid in the refinement of simulation programs designed to predict the fallout effects arising from surface and shallowly buried nuclear weapon detonations. These experiments, called the Condensation Debris Experiments (CDE), are intended to study the condensation/fractionation of material that is liberated following an initial deposition of laser energy onto a small, characterized target. The CDE effort also encompasses target develop… more
Date: April 1, 2005
Creator: Vidnovic, T., III; Bradley, K. S.; Debonnel, C. S.; Dipeso, G.; Fournier, K.; Karpenko, V. P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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