76
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Ross JS, Park HS, Berger R, Divol L, Kugland NL, Rozmus W, Ryutov D, Glenzer SH. Collisionless coupling of ion and electron temperatures in counterstreaming plasma flows. PHYSICAL REVIEW LETTERS 2013; 110:145005. [PMID: 25167001 DOI: 10.1103/physrevlett.110.145005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Indexed: 06/03/2023]
Abstract
Rapid electron and ion heating is observed in collisionless counterstreaming plasma flows and explained via a novel heating mechanism that couples the electron and ion temperatures. Recent experiments measure plasma conditions 4 mm from the surface of single foil (single plasma stream) and double foils (two counterstreaming plasmas) targets using Thomson scattering. Significant increases in electron and ion temperatures (from <100 eV to >1 keV) compared to the single foil geometry are observed. While electrons are heated by friction on opposite going ions, ion-ion collisions cannot explain the observed ion heating. Also, density and flow velocity measurements show negligible slow down and rule out stagnation. The nonlinear saturation of an acoustic two-stream electrostatic instability is predicted to couple the ion temperature to the electron temperature through the dynamic evolution of the instability threshold. Particle-in-cell simulations including both collisional and collisionless effects are compared to the experimental measurements and show rapid electron and ion heating consistent with the experimental measurements.
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77
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Falk K, Regan SP, Vorberger J, Crowley BJB, Glenzer SH, Hu SX, Murphy CD, Radha PB, Jephcoat AP, Wark JS, Gericke DO, Gregori G. Comparison between x-ray scattering and velocity-interferometry measurements from shocked liquid deuterium. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:043112. [PMID: 23679534 DOI: 10.1103/physreve.87.043112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 02/02/2013] [Indexed: 06/02/2023]
Abstract
The equation of state of light elements is essential to understand the structure of Jovian planets and inertial confinement fusion research. The Omega laser was used to drive a planar shock wave in the cryogenically cooled deuterium, creating warm dense matter conditions. X-ray scattering was used to determine the spectrum near the boundary of the collective and noncollective scattering regimes using a narrow band x-ray source in backscattering geometry. Our scattering spectra are thus sensitive to the individual electron motion as well as the collective plasma behavior and provide a measurement of the electron density, temperature, and ionization state. Our data are consistent with velocity-interferometry measurements previously taken on the same shocked deuterium conditions and presented by K. Falk et al. [High Energy Density Phys. 8, 76 (2012)]. This work presents a comparison of the two diagnostic systems and offers a detailed discussion of challenges encountered.
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78
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Ma T, Döppner T, Falcone RW, Fletcher L, Fortmann C, Gericke DO, Landen OL, Lee HJ, Pak A, Vorberger J, Wünsch K, Glenzer SH. X-ray scattering measurements of strong ion-ion correlations in shock-compressed aluminum. PHYSICAL REVIEW LETTERS 2013; 110:065001. [PMID: 23432260 DOI: 10.1103/physrevlett.110.065001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 11/19/2012] [Indexed: 06/01/2023]
Abstract
The strong ion-ion correlation peak characteristic of warm dense matter (WDM) is observed for the first time using simultaneous angularly, temporally, and spectrally resolved x-ray scattering measurements in laser-driven shock-compressed aluminum. Laser-produced molybdenum x-ray line emission at an energy of 17.9 keV is employed to probe aluminum compressed to a density of ρ>8 g/cm(3). We observe a well pronounced peak in the static structure factor at a wave number of k=4.0 Å(-1). The measurements of the magnitude and position of this correlation peak are precise enough to test different theoretical models for the ion structure and show that only models taking the complex interaction in WDM into account agree with the data. This also demonstrates a new highly accurate diagnostic to directly measure the state of compression of warm dense matter.
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79
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Regan SP, Falk K, Gregori G, Radha PB, Hu SX, Boehly TR, Crowley BJB, Glenzer SH, Landen OL, Gericke DO, Döppner T, Meyerhofer DD, Murphy CD, Sangster TC, Vorberger J. Inelastic x-ray scattering from shocked liquid deuterium. PHYSICAL REVIEW LETTERS 2012; 109:265003. [PMID: 23368573 DOI: 10.1103/physrevlett.109.265003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Indexed: 06/01/2023]
Abstract
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(α) line emission at 2.96 keV. 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)×10(23) cm(-3), and an ionization of 0.8 (-0.25, +0.15). 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.
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80
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White TG, Vorberger J, Brown CRD, Crowley BJB, Davis P, Glenzer SH, Harris JWO, Hochhaus DC, Le Pape S, Ma T, Murphy CD, Neumayer P, Pattison LK, Richardson S, Gericke DO, Gregori G. Observation of inhibited electron-ion coupling in strongly heated graphite. Sci Rep 2012. [PMID: 23189238 PMCID: PMC3506979 DOI: 10.1038/srep00889] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Creating non-equilibrium states of matter with highly unequal electron and lattice temperatures (T(ele)≠T(ion)) allows unsurpassed insight into the dynamic coupling between electrons and ions through time-resolved energy relaxation measurements. Recent studies on low-temperature laser-heated graphite suggest a complex energy exchange when compared to other materials. To avoid problems related to surface preparation, crystal quality and poor understanding of the energy deposition and transport mechanisms, we apply a different energy deposition mechanism, via laser-accelerated protons, to isochorically and non-radiatively heat macroscopic graphite samples up to temperatures close to the melting threshold. Using time-resolved x ray diffraction, we show clear evidence of a very small electron-ion energy transfer, yielding approximately three times longer relaxation times than previously reported. This is indicative of the existence of an energy transfer bottleneck in non-equilibrium warm dense matter.
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81
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Michel P, Rozmus W, Williams EA, Divol L, Berger RL, Town RPJ, Glenzer SH, Callahan DA. Stochastic ion heating from many overlapping laser beams in fusion plasmas. PHYSICAL REVIEW LETTERS 2012; 109:195004. [PMID: 23215392 DOI: 10.1103/physrevlett.109.195004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Indexed: 06/01/2023]
Abstract
In this Letter, we show through numerical simulations and analytical results that overlapping multiple (N) laser beams in plasmas can lead to strong stochastic ion heating from many (~N(2)) electrostatic perturbations driven by beat waves between pairs of laser beams. For conditions typical of inertial-confinement-fusion experiment conditions, hundreds of such beat waves are driven in mm(3)-scale plasmas, leading to ion heating rates of several keV/ns. This mechanism saturates cross-beam energy transfer, with a reduction of linear gains by a factor ~4-5 and can strongly modify the overall hydrodynamics evolution of such laser-plasma systems.
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82
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Gatu Johnson M, Frenje JA, Casey DT, Li CK, Séguin FH, Petrasso R, Ashabranner R, Bionta RM, Bleuel DL, Bond EJ, Caggiano JA, Carpenter A, Cerjan CJ, Clancy TJ, Doeppner T, Eckart MJ, Edwards MJ, Friedrich S, Glenzer SH, Haan SW, Hartouni EP, Hatarik R, Hatchett SP, Jones OS, Kyrala G, Le Pape S, Lerche RA, Landen OL, Ma T, MacKinnon AJ, McKernan MA, Moran MJ, Moses E, Munro DH, McNaney J, Park HS, Ralph J, Remington B, Rygg JR, Sepke SM, Smalyuk V, Spears B, Springer PT, Yeamans CB, Farrell M, Jasion D, Kilkenny JD, Nikroo A, Paguio R, Knauer JP, Glebov VY, Sangster TC, Betti R, Stoeckl C, Magoon J, Shoup MJ, Grim GP, Kline J, Morgan GL, Murphy TJ, Leeper RJ, Ruiz CL, Cooper GW, Nelson AJ. Neutron spectrometry--an essential tool for diagnosing implosions at the National Ignition Facility (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10D308. [PMID: 23126835 DOI: 10.1063/1.4728095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
DT neutron yield (Y(n)), ion temperature (T(i)), and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of inertial confinement fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-time-of-flight (nTOF) spectrometers and a magnetic recoil spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the complementarity required for reliable measurements of Y(n), T(i), and dsr. From the measured dsr value, an areal density (ρR) is determined through the relationship ρR(tot) (g∕cm(2)) = (20.4 ± 0.6) × dsr(10-12 MeV). The proportionality constant is determined considering implosion geometry, neutron attenuation, and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration of the as-built spectrometers, which are now performing to the required accuracy. Recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental ignition threshold factor (ITFx), which is a function of dsr (or fuel ρR) and Y(n), has improved almost two orders of magnitude since the first shot in September, 2010.
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83
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Ma T, Izumi N, Tommasini R, Bradley DK, Bell P, Cerjan CJ, Dixit S, Döppner T, Jones O, Kline JL, Kyrala G, Landen OL, LePape S, Mackinnon AJ, Park HS, Patel PK, Prasad RR, Ralph J, Regan SP, Smalyuk VA, Springer PT, Suter L, Town RPJ, Weber SV, Glenzer SH. Imaging of high-energy x-ray emission from cryogenic thermonuclear fuel implosions on the NIF. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10E115. [PMID: 23126937 DOI: 10.1063/1.4733313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide broadband time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered implosions. This diagnostic measures the temperature- and density-sensitive bremsstrahlung emission and provides estimates of hot spot mass, mix mass, and pressure.
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84
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Pollock BB, Meinecke J, Kuschel S, Ross JS, Shaw JL, Stoafer C, Divol L, Tynan GR, Glenzer SH. Simultaneous imaging electron- and ion-feature Thomson scattering measurements of radiatively heated Xe. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10E348. [PMID: 23127005 DOI: 10.1063/1.4740526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Uniform density and temperature Xe plasmas have been produced over >4 mm scale-lengths using x-rays generated in a cylindrical Pb cavity. The cavity is 750 μm in depth and diameter, and is heated by a 300 J, 2 ns square, 1054 nm laser pulse focused to a spot size of 200 μm at the cavity entrance. The plasma is characterized by simultaneous imaging Thomson scattering measurements from both the electron and ion scattering features. The electron feature measurement determines the spatial electron density and temperature profile, and using these parameters as constraints in the ion feature analysis allows an accurate determination of the charge state of the Xe ions. The Thomson scattering probe beam is 40 J, 200 ps, and 527 nm, and is focused to a 100 μm spot size at the entrance of the Pb cavity. Each system has a spatial resolution of 25 μm, a temporal resolution of 200 ps (as determined by the probe duration), and a spectral resolution of 2 nm for the electron feature system and 0.025 nm for the ion feature system. The experiment is performed in a Xe filled target chamber at a neutral pressure of 3-10 Torr, and the x-rays produced in the Pb ionize and heat the Xe to a charge state of 20±4 at up to 200 eV electron temperatures.
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85
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Pak A, Divol L, Weber S, Döppner T, Kyrala GA, Kilne J, Izumi N, Glenn S, Ma T, Town RP, Bradley DK, Glenzer SH. Diagnosing radiative shocks from deuterium and tritium implosions on NIF. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10E507. [PMID: 23127014 DOI: 10.1063/1.4729498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
During the recent ignition tuning campaign at the National Ignition Facility, layered cryogenic deuterium and tritium capsules were imploded via x-ray driven ablation. The hardened gated x-ray imager diagnostic temporally and spatially resolves the x-ray emission from the core of the capsule implosion at energies above ~8 keV. On multiple implosions, ~200-400 ps after peak compression a spherically expanding radiative shock has been observed. This paper describes the methods used to characterize the radial profile and rate of expansion of the shock induced x-ray emission.
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86
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Döppner T, Dewald EL, Divol L, Thomas CA, Burns S, Celliers PM, Izumi N, Kline JL, LaCaille G, McNaney JM, Prasad RR, Robey HF, Glenzer SH, Landen OL. Hard x-ray (>100 keV) imager to measure hot electron preheat for indirectly driven capsule implosions on the NIF. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10E508. [PMID: 23127015 DOI: 10.1063/1.4731742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We have fielded a hard x-ray (>100 keV) imager with high aspect ratio pinholes to measure the spatially resolved bremsstrahlung emission from energetic electrons slowing in a plastic ablator shell during indirectly driven implosions at the National Ignition Facility. These electrons are generated in laser plasma interactions and are a source of preheat to the deuterium-tritium fuel. First measurements show that hot electron preheat does not limit obtaining the fuel areal densities required for ignition and burn.
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87
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Ross JS, Park HS, Amendt P, Divol L, Kugland NL, Rozmus W, Glenzer SH. Thomson scattering diagnostic for the measurement of ion species fraction. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10E323. [PMID: 23126981 DOI: 10.1063/1.4731007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Simultaneous Thomson scattering measurements of collective electron-plasma and ion-acoustic fluctuations have been utilized to determine ion species fraction from laser produced CH plasmas. The CH(2) foil is heated with 10 laser beams, 500 J per beam, at the Omega Laser facility. Thomson scattering measurements are made 4 mm from the foil surface using a 30 J 2ω probe laser with a 1 ns pulse length. Using a series of target shots the plasma evolution is measured from 2.5 ns to 9 ns after the rise of the heater beams. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the two-ion species theoretical form factor for the ion feature such that the ion temperature, plasma flow velocity and ion species fraction are determined. The ion species fraction is determined to an accuracy of ±0.06 in species fraction.
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88
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Hau-Riege SP, Graf A, Döppner T, London RA, Krzywinski J, Fortmann C, Glenzer SH, Frank M, Sokolowski-Tinten K, Messerschmidt M, Bostedt C, Schorb S, Bradley JA, Lutman A, Rolles D, Rudenko A, Rudek B. Ultrafast transitions from solid to liquid and plasma states of graphite induced by x-ray free-electron laser pulses. PHYSICAL REVIEW LETTERS 2012; 108:217402. [PMID: 23003301 DOI: 10.1103/physrevlett.108.217402] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Indexed: 06/01/2023]
Abstract
We used photon pulses from an x-ray free-electron laser to study ultrafast x-ray-induced transitions of graphite from solid to liquid and plasma states. This was accomplished by isochoric heating of graphite samples and simultaneous probing via Bragg and diffuse scattering at high time resolution. We observe that disintegration of the crystal lattice and ion heating of up to 5 eV occur within tens of femtoseconds. The threshold fluence for Bragg-peak degradation is smaller and the ion-heating rate is faster than current x-ray-matter interaction models predict.
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89
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Mackinnon AJ, Kline JL, Dixit SN, Glenzer SH, Edwards MJ, Callahan DA, Meezan NB, Haan SW, Kilkenny JD, Döppner T, Farley DR, Moody JD, Ralph JE, MacGowan BJ, Landen OL, Robey HF, Boehly TR, Celliers PM, Eggert JH, Krauter K, Frieders G, Ross GF, Hicks DG, Olson RE, Weber SV, Spears BK, Salmonsen JD, Michel P, Divol L, Hammel B, Thomas CA, Clark DS, Jones OS, Springer PT, Cerjan CJ, Collins GW, Glebov VY, Knauer JP, Sangster C, Stoeckl C, McKenty P, McNaney JM, Leeper RJ, Ruiz CL, Cooper GW, Nelson AG, Chandler GGA, Hahn KD, Moran MJ, Schneider MB, Palmer NE, Bionta RM, Hartouni EP, LePape S, Patel PK, Izumi N, Tommasini R, Bond EJ, Caggiano JA, Hatarik R, Grim GP, Merrill FE, Fittinghoff DN, Guler N, Drury O, Wilson DC, Herrmann HW, Stoeffl W, Casey DT, Johnson MG, Frenje JA, Petrasso RD, Zylestra A, Rinderknecht H, Kalantar DH, Dzenitis JM, Di Nicola P, Eder DC, Courdin WH, Gururangan G, Burkhart SC, Friedrich S, Blueuel DL, Bernstein LA, Eckart MJ, Munro DH, Hatchett SP, Macphee AG, Edgell DH, Bradley DK, Bell PM, Glenn SM, Simanovskaia N, Barrios MA, Benedetti R, Kyrala GA, Town RPJ, Dewald EL, Milovich JL, Widmann K, Moore AS, LaCaille G, Regan SP, Suter LJ, Felker B, Ashabranner RC, Jackson MC, Prasad R, Richardson MJ, Kohut TR, Datte PS, Krauter GW, Klingman JJ, Burr RF, Land TA, Hermann MR, Latray DA, Saunders RL, Weaver S, Cohen SJ, Berzins L, Brass SG, Palma ES, Lowe-Webb RR, McHalle GN, Arnold PA, Lagin LJ, Marshall CD, Brunton GK, Mathisen DG, Wood RD, Cox JR, Ehrlich RB, Knittel KM, Bowers MW, Zacharias RA, Young BK, Holder JP, Kimbrough JR, Ma T, La Fortune KN, Widmayer CC, Shaw MJ, Erbert GV, Jancaitis KS, DiNicola JM, Orth C, Heestand G, Kirkwood R, Haynam C, Wegner PJ, Whitman PK, Hamza A, Dzenitis EG, Wallace RJ, Bhandarkar SD, Parham TG, Dylla-Spears R, Mapoles ER, Kozioziemski BJ, Sater JD, Walters CF, Haid BJ, Fair J, Nikroo A, Giraldez E, Moreno K, Vanwonterghem B, Kauffman RL, Batha S, Larson DW, Fortner RJ, Schneider DH, Lindl JD, Patterson RW, Atherton LJ, Moses EI. Assembly of high-areal-density deuterium-tritium fuel from indirectly driven cryogenic implosions. PHYSICAL REVIEW LETTERS 2012; 108:215005. [PMID: 23003274 DOI: 10.1103/physrevlett.108.215005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Indexed: 06/01/2023]
Abstract
The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement. These conditions were obtained using 192 laser beams with total energy of 1-1.6 MJ and peak power up to 420 TW to create a hohlraum drive with a shaped power profile, peaking at a soft x-ray radiation temperature of 275-300 eV. This pulse delivered a series of shocks that compressed a capsule containing cryogenic deuterium-tritium to a radius of 25-35 μm. Neutron images of the implosion were used to estimate a fuel density of 500-800 g cm(-3).
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90
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Fortmann C, Lee HJ, Döppner T, Falcone RW, Kritcher AL, Landen OL, Glenzer SH. Measurement of the adiabatic index in be compressed by counterpropagating shocks. PHYSICAL REVIEW LETTERS 2012; 108:175006. [PMID: 22680877 DOI: 10.1103/physrevlett.108.175006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Indexed: 06/01/2023]
Abstract
We report on the first direct measurement of the adiabatic index γ through x-ray Thomson scattering from shock-compressed beryllium. 9 keV x-ray photons probe the bulk properties of matter during the collision of two counterpropagating shocks. This novel experimental technique determines γ by using only the measured mass densities and vanishing particle velocity at the point of shock collision to close the Rankine-Hugoniot equations. We find γ>5/3 at 3× compression, clearly different from ideal gas behavior. At 6× compression, γ shows the convergence to the ideal gas limit, in agreement with linear scaling laws.
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91
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Visco AJ, Drake RP, Glenzer SH, Döppner T, Gregori G, Froula DH, Grosskopf MJ. Measurement of radiative shock properties by x-ray Thomson scattering. PHYSICAL REVIEW LETTERS 2012; 108:145001. [PMID: 22540798 DOI: 10.1103/physrevlett.108.145001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Indexed: 05/31/2023]
Abstract
X-ray Thomson scattering has enabled us to measure the temperature of a shocked layer, produced in the laboratory, that is relevant to shocks emerging from supernovas. High energy lasers are used to create a shock in argon gas which is probed by x-ray scattering. The scattered, inelastic Compton feature allows inference of the electron temperature. It is measured to be 34 eV in the radiative precursor and ∼60 eV near the shock. Comparison of energy fluxes implied by the data demonstrates that the shock wave is strongly radiative.
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92
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Döppner T, Thomas CA, Divol L, Dewald EL, Celliers PM, Bradley DK, Callahan DA, Dixit SN, Harte JA, Glenn SM, Haan SW, Izumi N, Kyrala GA, LaCaille G, Kline JK, Kruer WL, Ma T, MacKinnon AJ, McNaney JM, Meezan NB, Robey HF, Salmonson JD, Suter LJ, Zimmerman GB, Edwards MJ, MacGowan BJ, Kilkenny JD, Lindl JD, Van Wonterghem BM, Atherton LJ, Moses EI, Glenzer SH, Landen OL. Direct measurement of energetic electrons coupling to an imploding low-adiabat inertial confinement fusion capsule. PHYSICAL REVIEW LETTERS 2012; 108:135006. [PMID: 22540711 DOI: 10.1103/physrevlett.108.135006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Indexed: 05/31/2023]
Abstract
We have imaged hard x-ray (>100 keV) bremsstrahlung emission from energetic electrons slowing in a plastic ablator shell during indirectly driven implosions at the National Ignition Facility. We measure 570 J in electrons with E>100 keV impinging on the fusion capsule under ignition drive conditions. This translates into an acceptable increase in the adiabat α, defined as the ratio of total deuterium-tritium fuel pressure to Fermi pressure, of 3.5%. The hard x-ray observables are consistent with detailed radiative-hydrodynamics simulations, including the sourcing and transport of these high energy electrons.
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93
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Pollock BB, Clayton CE, Ralph JE, Albert F, Davidson A, Divol L, Filip C, Glenzer SH, Herpoldt K, Lu W, Marsh KA, Meinecke J, Mori WB, Pak A, Rensink TC, Ross JS, Shaw J, Tynan GR, Joshi C, Froula DH. Demonstration of a narrow energy spread, ∼0.5 GeV electron beam from a two-stage laser wakefield accelerator. PHYSICAL REVIEW LETTERS 2011; 107:045001. [PMID: 21867013 DOI: 10.1103/physrevlett.107.045001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Indexed: 05/31/2023]
Abstract
Laser wakefield acceleration of electrons holds great promise for producing ultracompact stages of GeV scale, high-quality electron beams for applications such as x-ray free electron lasers and high-energy colliders. Ultrahigh intensity laser pulses can be self-guided by relativistic plasma waves (the wake) over tens of vacuum diffraction lengths, to give >1 GeV energy in centimeter-scale low density plasmas using ionization-induced injection to inject charge into the wake even at low densities. By restricting electron injection to a distinct short region, the injector stage, energetic electron beams (of the order of 100 MeV) with a relatively large energy spread are generated. Some of these electrons are then further accelerated by a second, longer accelerator stage, which increases their energy to ∼0.5 GeV while reducing the relative energy spread to <5% FWHM.
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94
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Kritcher AL, Döppner T, Fortmann C, Ma T, Landen OL, Wallace R, Glenzer SH. In-flight measurements of capsule shell adiabats in laser-driven implosions. PHYSICAL REVIEW LETTERS 2011; 107:015002. [PMID: 21797548 DOI: 10.1103/physrevlett.107.015002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Indexed: 05/31/2023]
Abstract
We present the first x-ray Thomson scattering measurements of temperature and density from spherically imploding matter. The shape of the Compton downscattered spectrum provides a first-principles measurement of the electron velocity distribution function, dependent on T(e) and the Fermi temperature T(F)∼n(e)(2/3). In-flight compressions of Be and CH targets reach 6-13 times solid density, with T(e)/T(F)∼0.4-0.7 and Γ(ii)∼5, resulting in minimum adiabats of ∼1.6-2. These measurements are consistent with low-entropy implosions and predictions by radiation-hydrodynamic modeling.
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95
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Michel P, Divol L, Town RPJ, Rosen MD, Callahan DA, Meezan NB, Schneider MB, Kyrala GA, Moody JD, Dewald EL, Widmann K, Bond E, Kline JL, Thomas CA, Dixit S, Williams EA, Hinkel DE, Berger RL, Landen OL, Edwards MJ, MacGowan BJ, Lindl JD, Haynam C, Suter LJ, Glenzer SH, Moses E. Three-wavelength scheme to optimize hohlraum coupling on the National Ignition Facility. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:046409. [PMID: 21599318 DOI: 10.1103/physreve.83.046409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/04/2011] [Indexed: 05/30/2023]
Abstract
By using three tunable wavelengths on different cones of laser beams on the National Ignition Facility, numerical simulations show that the energy transfer between beams can be tuned to redistribute the energy within the cones of beams most prone to backscatter instabilities. These radiative hydrodynamics and laser-plasma interaction simulations have been tested against large-scale hohlraum experiments with two tunable wavelengths and reproduce the hohlraum energetics and symmetry. Using a third wavelength provides a greater level of control of the laser energy distribution and coupling in the hohlraum, and could significantly reduce stimulated Raman scattering losses and increase the hohlraum radiation drive while maintaining a good implosion symmetry.
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Glenzer SH, MacGowan BJ, Meezan NB, Adams PA, Alfonso JB, Alger ET, Alherz Z, Alvarez LF, Alvarez SS, Amick PV, Andersson KS, Andrews SD, Antonini GJ, Arnold PA, Atkinson DP, Auyang L, Azevedo SG, Balaoing BNM, Baltz JA, Barbosa F, Bardsley GW, Barker DA, Barnes AI, Baron A, Beeler RG, Beeman BV, Belk LR, Bell JC, Bell PM, Berger RL, Bergonia MA, Bernardez LJ, Berzins LV, Bettenhausen RC, Bezerides L, Bhandarkar SD, Bishop CL, Bond EJ, Bopp DR, Borgman JA, Bower JR, Bowers GA, Bowers MW, Boyle DT, Bradley DK, Bragg JL, Braucht J, Brinkerhoff DL, Browning DF, Brunton GK, Burkhart SC, Burns SR, Burns KE, Burr B, Burrows LM, Butlin RK, Cahayag NJ, Callahan DA, Cardinale PS, Carey RW, Carlson JW, Casey AD, Castro C, Celeste JR, Chakicherla AY, Chambers FW, Chan C, Chandrasekaran H, Chang C, Chapman RF, Charron K, Chen Y, Christensen MJ, Churby AJ, Clancy TJ, Cline BD, Clowdus LC, Cocherell DG, Coffield FE, Cohen SJ, Costa RL, Cox JR, Curnow GM, Dailey MJ, Danforth PM, Darbee R, Datte PS, Davis JA, Deis GA, Demaret RD, Dewald EL, Di Nicola P, Di Nicola JM, Divol L, Dixit S, Dobson DB, Doppner T, Driscoll JD, Dugorepec J, Duncan JJ, Dupuy PC, Dzenitis EG, Eckart MJ, Edson SL, Edwards GJ, Edwards MJ, Edwards OD, Edwards PW, Ellefson JC, Ellerbee CH, Erbert GV, Estes CM, Fabyan WJ, Fallejo RN, Fedorov M, Felker B, Fink JT, Finney MD, Finnie LF, Fischer MJ, Fisher JM, Fishler BT, Florio JW, Forsman A, Foxworthy CB, Franks RM, Frazier T, Frieder G, Fung T, Gawinski GN, Gibson CR, Giraldez E, Glenn SM, Golick BP, Gonzales H, Gonzales SA, Gonzalez MJ, Griffin KL, Grippen J, Gross SM, Gschweng PH, Gururangan G, Gu K, Haan SW, Hahn SR, Haid BJ, Hamblen JE, Hammel BA, Hamza AV, Hardy DL, Hart DR, Hartley RG, Haynam CA, Heestand GM, Hermann MR, Hermes GL, Hey DS, Hibbard RL, Hicks DG, Hinkel DE, Hipple DL, Hitchcock JD, Hodtwalker DL, Holder JP, Hollis JD, Holtmeier GM, Huber SR, Huey AW, Hulsey DN, Hunter SL, Huppler TR, Hutton MS, Izumi N, Jackson JL, Jackson MA, Jancaitis KS, Jedlovec DR, Johnson B, Johnson MC, Johnson T, Johnston MP, Jones OS, Kalantar DH, Kamperschroer JH, Kauffman RL, Keating GA, Kegelmeyer LM, Kenitzer SL, Kimbrough JR, King K, Kirkwood RK, Klingmann JL, Knittel KM, Kohut TR, Koka KG, Kramer SW, Krammen JE, Krauter KG, Krauter GW, Krieger EK, Kroll JJ, La Fortune KN, Lagin LJ, Lakamsani VK, Landen OL, Lane SW, Langdon AB, Langer SH, Lao N, Larson DW, Latray D, Lau GT, Le Pape S, Lechleiter BL, Lee Y, Lee TL, Li J, Liebman JA, Lindl JD, Locke SF, Loey HK, London RA, Lopez FJ, Lord DM, Lowe-Webb RR, Lown JG, Ludwigsen AP, Lum NW, Lyons RR, Ma T, MacKinnon AJ, Magat MD, Maloy DT, Malsbury TN, Markham G, Marquez RM, Marsh AA, Marshall CD, Marshall SR, Maslennikov IL, Mathisen DG, Mauger GJ, Mauvais MY, McBride JA, McCarville T, McCloud JB, McGrew A, McHale B, MacPhee AG, Meeker JF, Merill JS, Mertens EP, Michel PA, Miller MG, Mills T, Milovich JL, Miramontes R, Montesanti RC, Montoya MM, Moody J, Moody JD, Moreno KA, Morris J, Morriston KM, Nelson JR, Neto M, Neumann JD, Ng E, Ngo QM, Olejniczak BL, Olson RE, Orsi NL, Owens MW, Padilla EH, Pannell TM, Parham TG, Patterson RW, Pavel G, Prasad RR, Pendlton D, Penko FA, Pepmeier BL, Petersen DE, Phillips TW, Pigg D, Piston KW, Pletcher KD, Powell CL, Radousky HB, Raimondi BS, Ralph JE, Rampke RL, Reed RK, Reid WA, Rekow VV, Reynolds JL, Rhodes JJ, Richardson MJ, Rinnert RJ, Riordan BP, Rivenes AS, Rivera AT, Roberts CJ, Robinson JA, Robinson RB, Robison SR, Rodriguez OR, Rogers SP, Rosen MD, Ross GF, Runkel M, Runtal AS, Sacks RA, Sailors SF, Salmon JT, Salmonson JD, Saunders RL, Schaffer JR, Schindler TM, Schmitt MJ, Schneider MB, Segraves KS, Shaw MJ, Sheldrick ME, Shelton RT, Shiflett MK, Shiromizu SJ, Shor M, Silva LL, Silva SA, Skulina KM, Smauley DA, Smith BE, Smith LK, Solomon AL, Sommer S, Soto JG, Spafford NI, Speck DE, Springer PT, Stadermann M, Stanley F, Stone TG, Stout EA, Stratton PL, Strausser RJ, Suter LJ, Sweet W, Swisher MF, Tappero JD, Tassano JB, Taylor JS, Tekle EA, Thai C, Thomas CA, Thomas A, Throop AL, Tietbohl GL, Tillman JM, Town RPJ, Townsend SL, Tribbey KL, Trummer D, Truong J, Vaher J, Valadez M, Van Arsdall P, Van Prooyen AJ, Vergel de Dios EO, Vergino MD, Vernon SP, Vickers JL, Villanueva GT, Vitalich MA, Vonhof SA, Wade FE, Wallace RJ, Warren CT, Warrick AL, Watkins J, Weaver S, Wegner PJ, Weingart MA, Wen J, White KS, Whitman PK, Widmann K, Widmayer CC, Wilhelmsen K, Williams EA, Williams WH, Willis L, Wilson EF, Wilson BA, Witte MC, Work K, Yang PS, Young BK, Youngblood KP, Zacharias RA, Zaleski T, Zapata PG, Zhang H, Zielinski JS, Kline JL, Kyrala GA, Niemann C, Kilkenny JD, Nikroo A, Van Wonterghem BM, Atherton LJ, Moses EI. Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums. PHYSICAL REVIEW LETTERS 2011; 106:085004. [PMID: 21405580 DOI: 10.1103/physrevlett.106.085004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Indexed: 05/30/2023]
Abstract
We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.
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Kline JL, Glenzer SH, Olson RE, Suter LJ, Widmann K, Callahan DA, Dixit SN, Thomas CA, Hinkel DE, Williams EA, Moore AS, Celeste J, Dewald E, Hsing WW, Warrick A, Atherton J, Azevedo S, Beeler R, Berger R, Conder A, Divol L, Haynam CA, Kalantar DH, Kauffman R, Kyrala GA, Kilkenny J, Liebman J, Le Pape S, Larson D, Meezan NB, Michel P, Moody J, Rosen MD, Schneider MB, Van Wonterghem B, Wallace RJ, Young BK, Landen OL, MacGowan BJ. Observation of high soft x-ray drive in large-scale hohlraums at the National Ignition Facility. PHYSICAL REVIEW LETTERS 2011; 106:085003. [PMID: 21405579 DOI: 10.1103/physrevlett.106.085003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Indexed: 05/30/2023]
Abstract
The first soft x-ray radiation flux measurements from hohlraums using both a 96 and a 192 beam configuration at the National Ignition Facility have shown high x-ray conversion efficiencies of ∼85%-90%. These experiments employed gold vacuum hohlraums, 6.4 mm long and 3.55 mm in diameter, heated with laser energies between 150-635 kJ. The hohlraums reached radiation temperatures of up to 340 eV. These hohlraums for the first time reached coronal plasma conditions sufficient for two-electron processes and coronal heat conduction to be important for determining the radiation drive.
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98
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Pelka A, Gregori G, Gericke DO, Vorberger J, Glenzer SH, Günther MM, Harres K, Heathcote R, Kritcher AL, Kugland NL, Li B, Makita M, Mithen J, Neely D, Niemann C, Otten A, Riley D, Schaumann G, Schollmeier M, Tauschwitz A, Roth M. Ultrafast melting of carbon induced by intense proton beams. PHYSICAL REVIEW LETTERS 2010; 105:265701. [PMID: 21231678 DOI: 10.1103/physrevlett.105.265701] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 10/05/2010] [Indexed: 05/30/2023]
Abstract
Laser-produced proton beams have been used to achieve ultrafast volumetric heating of carbon samples at solid density. The isochoric melting of carbon was probed by a scattering of x rays from a secondary laser-produced plasma. From the scattering signal, we have deduced the fraction of the material that was melted by the inhomogeneous heating. The results are compared to different theoretical approaches for the equation of state which suggests modifications from standard models.
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Thiele R, Sperling P, Chen M, Bornath T, Fäustlin RR, Fortmann C, Glenzer SH, Kraeft WD, Pukhov A, Toleikis S, Tschentscher T, Redmer R. Thomson scattering on inhomogeneous targets. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:056404. [PMID: 21230599 DOI: 10.1103/physreve.82.056404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Indexed: 05/30/2023]
Abstract
The introduction of brilliant free-electron lasers enables new pump-probe experiments to characterize warm dense matter states. For instance, a short-pulse optical laser irradiates a liquid hydrogen jet that is subsequently probed with brilliant soft x-ray radiation. The strongly inhomogeneous plasma prepared by the optical laser is characterized with particle-in-cell simulations. The interaction of the soft x-ray probe radiation for different time delays between pump and probe with the inhomogeneous plasma is also taken into account via radiative hydrodynamic simulations. We calculate the respective scattering spectrum based on the Born-Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We can identify plasmon modes that are generated in different target regions and monitor their temporal evolution. Therefore, such pump-probe experiments are promising tools not only to measure the important plasma parameters density and temperature but also to gain valuable information about their time-dependent profile through the target. The method described here can be applied to various pump-probe scenarios by combining optical lasers and soft x ray, as well as x-ray sources.
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Moody JD, Datte P, Krauter K, Bond E, Michel PA, Glenzer SH, Divol L, Niemann C, Suter L, Meezan N, MacGowan BJ, Hibbard R, London R, Kilkenny J, Wallace R, Kline JL, Knittel K, Frieders G, Golick B, Ross G, Widmann K, Jackson J, Vernon S, Clancy T. Backscatter measurements for NIF ignition targets (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:10D921. [PMID: 21033953 DOI: 10.1063/1.3491035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of ∼15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.
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