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Progress in direct-drive inertial confinement fusion research at the
laboratory for laser energetics
R. L. McCrory D. D. Meyerhofer S. J. Loucks S. Skupsky R. Betti T. R. Boehly T. J.B. Collins R. S. Craxton J. A. Delettrez D. H. Edgell R. Epstein K. A. Fletcher C. Freeman J. A. Frenje V. Yu. Glebov V. N. Goncharov D. R. Harding I. V. Igumenshchev R. L. Keck J. D. Kilkenny J. P. Knauer C. K. Li J. Marciante J. A. Marozas F. J. Marshall A. V. Maximov P. W. McKenty S. F.B. Morse J. Myatt S. Padalino R. D. Petrasso P. B. Radha S. P. Regan T. C. Sangster F. H. Séguin W. Seka V. A. Smalyuk J. M. Soures C. Stoeckl B. Yaakobi J. D. Zuegel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):233-238
Direct-drive inertial confinement fusion (ICF) is
expected to demonstrate high gain on the National Ignition Facility (NIF) in
the next decade and is a leading candidate for inertial fusion energy
production. The demonstration of high areal densities in hydrodynamically
scaled cryogenic DT or D2 implosions with neutron yields that are a
significant fraction of the “clean” 1-D predictions will validate the
ignition-equivalent direct-drive target performance on the OMEGA laser at
the Laboratory for Laser Energetics (LLE). This paper highlights the
recent experimental and theoretical progress leading toward achieving this
validation in the next few years.
The NIF will initially be configured for X-ray drive and with no beams
placed at the target equator to provide a symmetric irradiation of a
direct-drive capsule. LLE is developing the “polar-direct-drive” (PDD)
approach that repoints beams toward the target equator. Initial 2-D
simulations have shown ignition. A unique “Saturn-like” plastic ring
around the equator refracts the laser light incident near the equator toward
the target, improving the drive uniformity.
LLE is currently constructing the multibeam, 2.6-kJ/beam, petawatt laser
system OMEGA EP. Integrated fast-ignition experiments, combining the OMEGA
EP and OMEGA Laser Systems, will begin in FY08. 相似文献
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Smalyuk VA Shvarts D Betti R Delettrez JA Edgell DH Glebov VY Goncharov VN McCrory RL Meyerhofer DD Radha PB Regan SP Sangster TC Seka W Skupsky S Stoeckl C Yaakobi B Frenje JA Li CK Petrasso RD Séguin FH 《Physical review letters》2008,100(18):185005
The compression of direct-drive, spherical implosions is studied using cryogenic D2 targets on the 60-beam, 351-nm OMEGA laser with intensities ranging from approximately 3x10(14) to approximately 1x10(15) W/cm2. The hard-x-ray signal from hot electrons generated by laser-plasma instabilities increases with laser intensity, while the areal density decreases. Mitigating hot-electron production, by reducing the laser intensity to approximately 3x10(14) W/cm2, results in areal density of the order of approximately 140 mg/cm2, in good agreement with 1D simulations. These results will be considered in future direct-drive-ignition designs. 相似文献
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McCrory CC Devadoss A Ottenwaelder X Lowe RD Stack TD Chidsey CE 《Journal of the American Chemical Society》2011,133(11):3696-3699
A Cu(I) complex of 3-ethynyl-phenanthroline covalently immobilized onto an azide-modified glassy carbon surface is an active electrocatalyst for the four-electron (4-e) reduction of O(2) to H(2)O. The rate of O(2) reduction is second-order in Cu coverage at moderate overpotential, suggesting that two Cu(I) species are necessary for efficient 4-e reduction of O(2). Mechanisms for O(2) reduction are proposed that are consistent with the observations for this covalently immobilized system and previously reported results for a similar physisorbed Cu(I) system. 相似文献
7.
Frédéric Bihan Matthias Franz Clint McCrory Joost van Bihan 《manuscripta mathematica》2006,120(2):217-232
A complex algebraic variety X defined over the real numbers is called an M-variety if the sum of its Betti numbers (for homology with closed supports and coefficients in
) coincides with the corresponding sum for the real part of X. It has been known for a long time that any nonsingular complete toric variety is an M-variety. In this paper we consider whether this remains true for toric varieties that are singular or not complete, and we give a positive answer when the dimension of X is less than or equal to 3 or when X is complete with isolated singularities.An erratum to this article can be found at 相似文献
8.
B Yaakobi P Bourke Y Conturie J Delettrez J.M Forsyth R.D Frankel L.M Goldman R.L McCrory W Seka J.M Soures A.J Burek R.E Deslattes 《Optics Communications》1981,38(3):196-200
High conversion efficiency of laser energy into X-rays from a laser irradiated target is of great interest for a variety of dynamical (pulsed) studies, e.g.: radiography of laser-imploded targets, structure determination by diffraction and absorption fine-structure, and X-ray laser pumping. We report here on a frequency tripled Nd : glass laser used to irradiate targets of various materials at ~5 x 1014W/cm2. We find conversion efficiencies of between 1% and 0.1% (with respect to the incident laser energy) for individual X-ray lines between 1.8 and 7.8 keV. These efficiencies are more than an order of magnitude higher than whose achieved with 1.06 μm lasers. 相似文献
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McCrory CC Ottenwaelder X Stack TD Chidsey CE 《The journal of physical chemistry. A》2007,111(49):12641-12650
Mononuclear Cu complexes with a 1,10-phenanthroline-based ligand adsorbed onto an edge-plane graphite electrode act as electrocatalysts for the 4-electron reduction of O2 to H2O. A mechanism is proposed for the electrocatalytic O2 reduction that accounts for the observed redox and kinetic dependences on coordinating anions and proton donors in the buffer. Systematic increases of ligand electron-withdrawing properties and/or the steric demands near the Cu center increase the E0 of the Cu catalysts but decrease the rate of O2 reduction. The kinetic rate of O2 reduction at E0, reported as kinetic current divided by catalyst redox charge, decreases as E0 increases: from 16 s(-1) measured at E0 in air-saturated solutions for adsorbed Cu(phen) to 0.4 s(-1) for Cu(2,9-Et2-phen). The maximum value of E for which catalytic activity can be attained is estimated to be +350 mV vs NHE. Near E0, the kinetic current deviates from that expected if O2 binding were the sole rate-limiting step. This indicates that one or more of the electrochemical reduction steps are rate limiting at potentials near E0. 相似文献
10.
Sangster TC Goncharov VN Radha PB Smalyuk VA Betti R Craxton RS Delettrez JA Edgell DH Glebov VY Harding DR Jacobs-Perkins D Knauer JP Marshall FJ McCrory RL McKenty PW Meyerhofer DD Regan SP Seka W Short RW Skupsky S Soures JM Stoeckl C Yaakobi B Shvarts D Frenje JA Li CK Petrasso RD Séguin FH 《Physical review letters》2008,100(18):185006
The first observation of ignition-relevant areal-density deuterium from implosions of capsules with cryogenic fuel layers at ignition-relevant adiabats is reported. The experiments were performed on the 60-beam, 30-kJUV OMEGA Laser System [T. R. Boehly, Opt. Commun. 133, 495 (1997)10.1016/S0030-4018(96)00325-2]. Neutron-averaged areal densities of 202+/-7 mg/cm2 and 182+/-7 mg/cm2 (corresponding to estimated peak fuel densities in excess of 100 g/cm3) were inferred using an 18-kJ direct-drive pulse designed to put the converging fuel on an adiabat of 2.5. These areal densities are in good agreement with the predictions of hydrodynamic simulations indicating that the fuel adiabat can be accurately controlled under ignition-relevant conditions. 相似文献