排序方式: 共有25条查询结果,搜索用时 140 毫秒
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Celliers PM Collins GW Da Silva LB Gold DM Cauble R Wallace RJ Foord ME Hammel BA 《Physical review letters》2000,84(24):5564-5567
Simultaneous measurements of shock velocity and optical reflectance at 1064, 808, and 404 nm of a high pressure shock front propagating through liquid deuterium show a continuous increase in reflectance from below 10% and saturating at approximately (40-60)% in the range of shock velocities from 12 to 20 &mgr;m/ns (pressure range 17-50 GPa). The high optical reflectance is evidence that the shocked deuterium reaches a conducting state characteristic of a metallic fluid. Above 20 &mgr;m/ns shock velocity (50 GPa pressure) reflectance is constant indicating that the transformation is substantially complete. 相似文献
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R. Cauble 《Journal of Quantitative Spectroscopy & Radiative Transfer》1982,28(1):41-46
The plasma polarization shift (PPS) of spectral lines from hydrogenic ions immersed in a dense hydrogen plasma is examined by using an interaction model that includes the effects of perturbers exterior to the bound electron orbit. The semiclassical model is compared with (a) experimental shifts of Paschen lines in He+ at densities of 1016–1017 cm?3 and temperatures of a few eV and (b) self-consistent potential calculations for Lyman α in Ne+9 and Ar+17 at densities of 1024–1025 cm?3 and temperatures of 500–2000 eV. 相似文献
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Batani D Morelli A Tomasini M Benuzzi-Mounaix A Philippe F Koenig M Marchet B Masclet I Rabec M Reverdin Ch Cauble R Celliers P Collins G Da Silva L Hall T Moret M Sacchi B Baclet P Cathala B 《Physical review letters》2002,88(23):235502
We present equation of state points for iron, in the pressure range 10-45 Mbar, the first obtained with laser-driven shock waves. The experiment has been performed with the high energy laser Phebus, optically smoothed with Kinoform phase plates. Our results double the set of existing experimental data at very high pressures showing good agreement with the predictions of the quotidian equation of state model and with previous results. 相似文献
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Bradley DK Eggert JH Hicks DG Celliers PM Moon SJ Cauble RC Collins GW 《Physical review letters》2004,93(19):195506
Laser generated shock reflectance data show that diamond undergoes a continuous transition from optically absorbing to reflecting between Hugoniot pressures 600
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Hui Chen D.D Meyerhofer S.C. Wilks R. Cauble F. Dollar K. Falk G. Gregori A. Hazi E.I. Moses C.D. Murphy J. Myatt J. Park J. Seely R. Shepherd A. Spitkovsky C. Stoeckl C.I. Szabo R. Tommasini C. Zulick P. Beiersdorfer 《High Energy Density Physics》2011,7(4):225-229
We review recent experimental results on the path to producing electron–positron pair plasmas using lasers. Relativistic pair-plasmas and jets are believed to exist in many astrophysical objects and are often invoked to explain energetic phenomena related to Gamma Ray Bursts and Black Holes. On earth, positrons from radioactive isotopes or accelerators are used extensively at low energies (sub-MeV) in areas related to surface science positron emission tomography and basic antimatter science. Experimental platforms capable of producing the high-temperature pair-plasma and high-flux jets required to simulate astrophysical positron conditions have so far been absent. In the past few years, we performed extensive experiments generating positrons with intense lasers where we found that relativistic electron and positron jets are produced by irradiating a solid gold target with an intense picosecond laser pulse. The positron temperatures in directions parallel and transverse to the beam both exceeded 0.5 MeV, and the density of electrons and positrons in these jets are of order 1016 cm−3 and 1013 cm−3, respectively. With the increasing performance of high-energy ultra-short laser pulses, we expect that a high-density, up to 1018 cm−3, relativistic pair-plasma is achievable, a novel regime of laboratory-produced hot dense matter. 相似文献
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A catalytic diastereo- and enantioselective method for tandem conjugate addition-aldol cyclization is described. This methodology enables the formation of five- and six-membered ring products from aromatic and aliphatic mono-enone mono-ketone precursors. Notably, in a single manipulation, three contiguous stereogenic centers are created with high levels of relative and absolute stereocontrol. 相似文献