Download or read book Measure ray Thomson Scattering Measurements from Shock Compressed Deuterium written by and published by . This book was released on 2011 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X ray Scattering Measurements of Dissociation induced Metallization of Dynamically Compressed Deuterium written by and published by . This book was released on 2016 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen, the simplest element in the universe, has a surprisingly complex phase diagram. Because of applications to planetary science, inertial confinement fusion and fundamental physics, its high-pressure properties have been the subject of intense study over the past two decades. While sophisticated static experiments have probed hydrogen's structure at ever higher pressures, studies examining the higher-temperature regime using dynamic compression have mostly been limited to optical measurement techniques. Here we present spectrally resolved x-ray scattering measurements from plasmons in dynamically compressed deuterium. Combined with Compton scattering, and velocity interferometry to determine shock pressure and mass density, this allows us to extract ionization state as a function of compression. Finally, the onset of ionization occurs close in pressure to where density functional theory-molecular dynamics (DFT-MD) simulations show molecular dissociation, suggesting hydrogen transitions from a molecular and insulating fluid to a conducting state without passing through an intermediate atomic phase.
Download or read book Measurement of Equation of State of Compressed Hydrogen and Deuterium written by Katerina Falk and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed understanding of the equation of state of light elements such as the hydrogen isotopes in the warm dense matter (WDM) regime is essential for the modeling of the inner structure of many astrophysical objects, in particular Jovian planets as well as inertial confinement fusion (ICF) research. In these systems quantum degeneracy and strong inter-particle forces play an important role making its theoretical description extremely challenging. The Omega laser was used to drive a planar shock wave in cryogenically cooled deuterium creating WDM conditions [1]. We used a set of independent diagnostics to measure the thermodynamic conditions of WDM including velocity interferometry (VISAR), streaked optical pyrometry (SOP) and x-ray Thomson scattering (XRTS). With a narrow-band x-ray backlighter probe at backscattering geometry the spectrally resolved XRTS accessed the boundary of collective and non-collective regimes making our measurement sensitive to both electron temperature and density. This work presents a full set of measurements of the thermodynamic properties for different laser intensity drives creating warm dense deuterium at various degrees of degeneracy and coupling. The measured electron densities and temperatures ranged between 0.2 and 2.15x 1023 cm-3 and 0.6 - 20 eV respectively. The scattering measurement confirmed the findings from the VISAR and SOP data and together density- functional molecular dynamics (DFT-MD) simulations provides a novel self-consistent approach for an accurate characterization of the microscopic structure of WDM [2]. Complementary to the laser compression work, findings from project employing static compression hydrogen with the use of diamond anvil cells is also be presented. The first direct measurement of the local field correction to the Coulomb interactions in degenerate plasma was obtained from inelastic scattering (20 keY probe) at the Diamond Light Source synchrotron facility [3].
Download or read book X ray Thomson Scattering Measurements of Temperature and Density from Multi shocked CH Capsules written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Proof-of-principle measurements of the electron densities, temperatures, and ionization states of spherically compressed multi-shocked CH (polystyrene) capsules have been achieved using spectrally resolved x-ray Thomson scattering. A total energy of 13.5 kJ incident on target is used to compress a 70 [mu]m thick CH shell above solid-mass density using three coalescing shocks. Separately, a laser-produced zinc He-[alpha] x-ray source at 9 keV delayed 200 ps-800 ps after maximum compression is used to probe the plasma in the non-collective scattering regime. The data show that x-ray Thomson scattering enables a complete description of the time-dependent hydrodynamic evolution of shock-compressed CH capsules, with a maximum measured density of [rho]> 6 g cm-3. Additionally, the results demonstrate that accurate measurements of x-ray scattering from bound-free transitions in the CH plasma demonstrate strong evidence that continuum lowering is the primary ionization mechanism of carbon L-shell electrons.
Download or read book Ultra fast X ray Thomson Scattering Measurements of Insulator metal Transition in Shock compressed Matter written by and published by . This book was released on 2008 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spectrally resolved scattering of ultra-short pulse laser-generated K-[alpha] x rays has been applied to measure the heating and compression of shocked solid-density lithium hydride. Two shocks launched by a nanosecond laser pulse coalesce yielding pressures of 400 gigapascals. The evolution of the intensity of the elastic (Rayleigh) scattering component indicates rapid heating to temperatures of 25,000 K on a 100 ps time scale. At shock coalescence, the scattering spectra show the collective plasmon oscillations indicating the transition to the dense metallic plasma state. The plasmon frequency determines the material compression, which is found to be a factor of three thereby reaching conditions in the laboratory important for studying astrophysics phenomena.
Download or read book Midra Waj jiqr rabb written by and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inelastic X ray Scattering from Shocked Liquid Deuterium written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fermi-degenerate plasma conditions created in liquid deuterium by a laser-ablation--driven shock wave were probed with noncollective, spectrally resolved, inelastic x-ray Thomson scattering employing Cl Ly[alpha] line emission at 2.96 keV. Thus, these first x-ray Thomson scattering measurements of the microscopic properties of shocked deuterium show an inferred spatially averaged electron temperature of 8±5 eV, an electron density of 2.2(±0.5)×1023 cm-3, and an ionization of 0.8 ( -0.25, +0.15). Our two-dimensional hydrodynamic simulations using equation-of-state models suited for the extreme parameters occurring in inertial confinement fusion research and planetary interiors are consistent with the experimental results.
Download or read book X ray Radiography and Scattering Diagnosis of Dense Shock Compressed Matter written by and published by . This book was released on 2009 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highly coupled Boron plasma has been probed by spectrally resolving an x-ray source scattered by the plasma. Electron density was inferred from the inelastic feature in the collective scattering regime. In addition, the mass density inferred from the non-collective X-ray Thomson scattering has been tested with independent characterization using X-ray radiography in the same drive condition. High-intensity laser produced K-alpha radiation was used as a backlighter for these dynamically compressed plasma experiments providing a high temporal resolution of the measurements. Mass density measurements from both methods are in good agreement. The measurements yield a compression of 1.3 in agreement with detailed radiation-hydrodynamic modeling. From the charge state measured in the non-collective regime and the electron density measured in the collective regime the mass density can then be constrained to 3.15 ± 0.16.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 1070 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fusion Energy Update written by and published by . This book was released on 1980 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X ray Thomson Scattering Measurements of Warm Dense Matter written by and published by . This book was released on 2012 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Collective X ray Thomson Scattering to Measure Temperature and Density of Warm Dense Matter written by and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collective x-ray Thomson scattering allows measuring plasmons, i.e electron plasma oscillations (Langmuir waves). This is manifest in the appearance of spectrally up- and down-shifted spectral features in addition to the Rayleigh signal. The ratio of the up- and down-shifted signals is directly related to detailed balance, allowing to determine the plasma temperature from first principles. The spectral shift of the plasmon signals is sensitive to temperature and electron density. We discuss the experimental considerations that have to be fulfilled to observe plasmon signals with x-ray Thomson scattering. As an example, we describe an experiment that used the Cl Ly-[alpha] x-ray line at 2.96 keV to measure collective Thomson scattering from solid beryllium, isochorically heated to 18 eV. Since temperature measurement based on detailed balance is based on first principles, this method is important to validate models that, for example, calculate the static ion-ion structure factor S{sub ii}(k).
Download or read book Absolute Equation of State Measurements of Shocked Liquid Deuterium Up to 200 GPa 2 Mbar written by and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results of the first measurements of density, shock speed and particle speed in compressed liquid deuterium at pressures in excess in 1 Mbar. We have performed equation of state (EOS) measurements on the principal Hugoniot of liquid deuterium from 0.2 to 2 Mbar. We employ high-resolution radiography to simultaneously measure the compression of the sample. We are also attempting to measure the color temperature of the shocked D2. Key to this effort is the development and implementation of interferometric methods in order to carefully characterized the profile and steadiness of the shock and the level of preheat in the samples. These experiments allow us to differentiate between the accepted EOS model for D2 and a new model which included the effects of molecular dissociation on the EOS.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1964 with total page 1004 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Physics and Controlled Nuclear Fusion Research written by and published by . This book was released on 1971 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Physics and Controlled Nuclear Fusion Research 1971 written by and published by . This book was released on 1971 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thomson Scattering Measurements on the High Beta Pinch Extrap T1 written by P. Karlsson and published by . This book was released on 1989 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
