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Chen Z, Hering P, Brown SB, Curry C, Tsui YY, Glenzer SH. A single-shot spatial chirp method for measuring initial AC conductivity evolution of femtosecond laser pulse excited warm dense matter. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11E548. [PMID: 27910393 DOI: 10.1063/1.4962057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
To study the rapid evolution of AC conductivity from ultrafast laser excited warm dense matter (WDM), a spatial chirp single-shot method is developed utilizing a crossing angle pump-probe configuration. The pump beam is shaped individually in two spatial dimensions so that it can provide both sufficient laser intensity to excite the material to warm dense matter state and a uniform time window of up to 1 ps with sub-100 fs FWHM temporal resolution. Temporal evolution of AC conductivity in laser excited warm dense gold was also measured.
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52
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Gauthier M, Kim JB, Curry CB, Aurand B, Gamboa EJ, Göde S, Goyon C, Hazi A, Kerr S, Pak A, Propp A, Ramakrishna B, Ruby J, Willi O, Williams GJ, Rödel C, Glenzer SH. High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11D827. [PMID: 27910336 DOI: 10.1063/1.4961270] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications.
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MacDonald MJ, Gorkhover T, Bachmann B, Bucher M, Carron S, Coffee RN, Drake RP, Ferguson KR, Fletcher LB, Gamboa EJ, Glenzer SH, Göde S, Hau-Riege SP, Kraus D, Krzywinski J, Levitan AL, Meiwes-Broer KH, O'Grady CP, Osipov T, Pardini T, Peltz C, Skruszewicz S, Swiggers M, Bostedt C, Fennel T, Döppner T. Measurement of high-dynamic range x-ray Thomson scattering spectra for the characterization of nano-plasmas at LCLS. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11E709. [PMID: 27910491 DOI: 10.1063/1.4960502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Atomic clusters can serve as ideal model systems for exploring ultrafast (∼100 fs) laser-driven ionization dynamics of dense matter on the nanometer scale. Resonant absorption of optical laser pulses enables heating to temperatures on the order of 1 keV at near solid density conditions. To date, direct probing of transient states of such nano-plasmas was limited to coherent x-ray imaging. Here we present the first measurement of spectrally resolved incoherent x-ray scattering from clusters, enabling measurements of transient temperature, densities, and ionization. Single shot x-ray Thomson scattering signals were recorded at 120 Hz using a crystal spectrometer in combination with a single-photon counting and energy-dispersive pnCCD. A precise pump laser collimation scheme enabled recording near background-free scattering spectra from Ar clusters with an unprecedented dynamic range of more than 3 orders of magnitude. Such measurements are important for understanding collective effects in laser-matter interactions on femtosecond time scales, opening new routes for the development of schemes for their ultrafast control.
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Fletcher LB, Zastrau U, Galtier E, Gamboa EJ, Goede S, Schumaker W, Ravasio A, Gauthier M, MacDonald MJ, Chen Z, Granados E, Lee HJ, Fry A, Kim JB, Roedel C, Mishra R, Pelka A, Kraus D, Barbrel B, Döppner T, Glenzer SH. High resolution x-ray Thomson scattering measurements from cryogenic hydrogen jets using the linac coherent light source. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11E524. [PMID: 27910564 DOI: 10.1063/1.4959792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present the first spectrally resolved measurements of x-rays scattered from cryogenic hydrogen jets in the single photon counting limit. The 120 Hz capabilities of the LCLS, together with a novel hydrogen jet design [J. B. Kim et al., Rev. Sci. Instrum. (these proceedings)], allow for the ability to record a near background free spectrum. Such high-dynamic-range x-ray scattering measurements enable a platform to study ultra-fast, laser-driven, heating dynamics of hydrogen plasmas. This measurement has been achieved using two highly annealed pyrolytic graphite crystal spectrometers to spectrally resolve 5.5 keV x-rays elastically and inelastically scattered from cryogenic hydrogen and focused on Cornell-SLAC pixel array detectors [S. Herrmann et al., Nucl. Instrum. Methods Phys. Res., Sect. A 718, 550 (2013)].
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Kraus D, Chapman DA, Kritcher AL, Baggott RA, Bachmann B, Collins GW, Glenzer SH, Hawreliak JA, Kalantar DH, Landen OL, Ma T, Le Pape S, Nilsen J, Swift DC, Neumayer P, Falcone RW, Gericke DO, Döppner T. X-ray scattering measurements on imploding CH spheres at the National Ignition Facility. Phys Rev E 2016; 94:011202. [PMID: 27575070 DOI: 10.1103/physreve.94.011202] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Indexed: 06/06/2023]
Abstract
We have performed spectrally resolved x-ray scattering measurements on highly compressed polystyrene at pressures of several tens of TPa (100 Mbar) created by spherically convergent shocks at the National Ignition Facility. Scattering data of line radiation at 9.0 keV were recorded from the dense plasma shortly after shock coalescence. Accounting for spatial gradients, opacity effects, and source broadening, we demonstrate the sensitivity of the elastic scattering component to carbon K-shell ionization while at the same time constraining the temperature of the dense plasma. For six times compressed polystyrene, we find an average temperature of 86 eV and carbon ionization state of 4.9, indicating that widely used ionization models need revision in order to be suitable for the extreme states of matter tested in our experiment.
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Kraus D, Döppner T, Kritcher AL, Yi A, Boehm K, Bachmann B, Divol L, Fletcher LB, Glenzer SH, Landen OL, Masters N, Saunders AM, Weber C, Falcone RW, Neumayer P. Platform for spectrally resolved x-ray scattering from imploding capsules at the National Ignition Facility. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1742-6596/717/1/012067] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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57
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Sperling P, Gamboa EJ, Lee HJ, Chung HK, Galtier E, Omarbakiyeva Y, Reinholz H, Röpke G, Zastrau U, Hastings J, Fletcher LB, Glenzer SH. Free-electron X-ray laser measurements of collisional-damped plasmons in isochorically heated warm dense matter. PHYSICAL REVIEW LETTERS 2015; 115:115001. [PMID: 26406836 DOI: 10.1103/physrevlett.115.115001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Indexed: 06/05/2023]
Abstract
We present the first highly resolved measurements of the plasmon spectrum in an ultrafast heated solid. Multi-keV x-ray photons from the Linac Coherent Light Source have been focused to one micrometer diameter focal spots producing solid density aluminum plasmas with a known electron density of n_{e}=1.8×10^{23} cm^{-3}. Detailed balance is observed through the intensity ratio of up- and down-shifted plasmons in x-ray forward scattering spectra measuring the electron temperature. The plasmon damping is treated by electron-ion collision models beyond the Born approximation to determine the electrical conductivity of warm dense aluminum.
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Plagemann KU, Rüter HR, Bornath T, Shihab M, Desjarlais MP, Fortmann C, Glenzer SH, Redmer R. Ab initio calculation of the ion feature in x-ray Thomson scattering. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:013103. [PMID: 26274290 DOI: 10.1103/physreve.92.013103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Indexed: 06/04/2023]
Abstract
The spectrum of x-ray Thomson scattering is proportional to the dynamic structure factor. An important contribution is the ion feature which describes elastic scattering of x rays off electrons. We apply an ab initio method for the calculation of the form factor of bound electrons, the slope of the screening cloud of free electrons, and the ion-ion structure factor in warm dense beryllium. With the presented method we can calculate the ion feature from first principles. These results will facilitate a better understanding of x-ray scattering in warm dense matter and an accurate measurement of ion temperatures which would allow determining nonequilibrium conditions, e.g., along shock propagation.
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Berger RL, Suter LJ, Divol L, London RA, Chapman T, Froula DH, Meezan NB, Neumayer P, Glenzer SH. Beyond the gain exponent: Effect of damping, scale length, and speckle length on stimulated scatter. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:031103. [PMID: 25871045 DOI: 10.1103/physreve.91.031103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Indexed: 06/04/2023]
Abstract
Three-dimensional wave propagation simulations and experiments show that the gain exponent, an often used metric to assess the likelihood of stimulated Brillouin scatter, is insufficient and must be augmented with another parameter, Nr, the ratio of the resonance length, Lres, to the laser speckle length. The damping rate of ion acoustic waves, ν, and thus Lres, which is proportional to ν, are easily varied with plasma species composition, e.g., by varying the ratio of hydrogen and carbon ions. As Nr decreases, stimulated Brillouin scattering increases despite the same gain exponent.
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Gauthier M, Fletcher LB, Ravasio A, Galtier E, Gamboa EJ, Granados E, Hastings JB, Heimann P, Lee HJ, Nagler B, Schropp A, Gleason A, Döppner T, LePape S, Ma T, Pak A, MacDonald MJ, Ali S, Barbrel B, Falcone R, Kraus D, Chen Z, Mo M, Wei M, Glenzer SH. New experimental platform to study high density laser-compressed matter. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11E616. [PMID: 25430362 DOI: 10.1063/1.4896175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have developed a new experimental platform at the Linac Coherent Light Source (LCLS) which combines simultaneous angularly and spectrally resolved x-ray scattering measurements. This technique offers a new insights on the structural and thermodynamic properties of warm dense matter. The < 50 fs temporal duration of the x-ray pulse provides near instantaneous snapshots of the dynamics of the compression. We present a proof of principle experiment for this platform to characterize a shock-compressed plastic foil. We observe the disappearance of the plastic semi-crystal structure and the formation of a compressed liquid ion-ion correlation peak. The plasma parameters of shock-compressed plastic can be measured as well, but requires an averaging over a few tens of shots.
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Döppner T, Kritcher AL, Neumayer P, Kraus D, Bachmann B, Burns S, Falcone RW, Glenzer SH, Hawreliak J, House A, Landen OL, LePape S, Ma T, Pak A, Swift D. Qualification of a high-efficiency, gated spectrometer for x-ray Thomson scattering on the National Ignition Facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11D617. [PMID: 25430193 DOI: 10.1063/1.4890253] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have designed, built, and successfully fielded a highly efficient and gated Bragg crystal spectrometer for x-ray Thomson scattering measurements on the National Ignition Facility (NIF). It utilizes a cylindrically curved Highly Oriented Pyrolytic Graphite crystal. Its spectral range of 7.4-10 keV is optimized for scattering experiments using a Zn He-α x-ray probe at 9.0 keV or Mo K-shell line emission around 18 keV in second diffraction order. The spectrometer has been designed as a diagnostic instrument manipulator-based instrument for the NIF target chamber at the Lawrence Livermore National Laboratory, USA. Here, we report on details of the spectrometer snout, its novel debris shield configuration and an in situ spectral calibration experiment with a Brass foil target, which demonstrated a spectral resolution of E/ΔE = 220 at 9.8 keV.
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Fletcher LB, Lee HJ, Barbrel B, Gauthier M, Galtier E, Nagler B, Döppner T, LePape S, Ma T, Pak A, Turnbull D, White T, Gregori G, Wei M, Falcone RW, Heimann P, Zastrau U, Hastings JB, Glenzer SH. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11E702. [PMID: 25430365 DOI: 10.1063/1.4891186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.
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Kraus D, Döppner T, Kritcher AL, Bachmann B, Chapman DA, Collins GW, Glenzer SH, Hawreliak JA, Landen OL, Ma T, Le Pape S, Neumayer P, Swift DC, Falcone RW. X-ray continuum emission spectroscopy from hot dense matter at Gbar pressures. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11D606. [PMID: 25430182 DOI: 10.1063/1.4890263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have measured the time-resolved x-ray continuum emission spectrum of ∼30 times compressed polystyrene created at stagnation of spherically convergent shock waves within the Gbar fundamental science campaign at the National Ignition Facility. From an exponential emission slope between 7.7 keV and 8.1 keV photon energy and using an emission model which accounts for reabsorption, we infer an average electron temperature of 375 ± 21 eV, which is in good agreement with HYDRA-1D simulations.
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64
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Zastrau U, Fletcher LB, Förster E, Galtier EC, Gamboa E, Glenzer SH, Heimann P, Marschner H, Nagler B, Schropp A, Wehrhan O, Lee HJ. Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:093106. [PMID: 25273706 DOI: 10.1063/1.4894821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a cylindrically curved GaAs x-ray spectrometer with energy resolution ΔE/E = 1.1 × 10(-4) and wave-number resolution of Δk/k = 3 × 10(-3), allowing plasmon scattering at the resolution limits of the Linac Coherent Light Source (LCLS) x-ray free-electron laser. It spans scattering wavenumbers of 3.6 to 5.2/Å in 100 separate bins, with only 0.34% wavenumber blurring. The dispersion of 0.418 eV/13.5 μm agrees with predictions within 1.3%. The reflection homogeneity over the entire wavenumber range was measured and used to normalize the amplitude of scattering spectra. The proposed spectrometer is superior to a mosaic highly annealed pyrolytic graphite spectrometer when the energy resolution needs to be comparable to the LCLS seeded bandwidth of 1 eV and a significant range of wavenumbers must be covered in one exposure.
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65
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Zastrau U, Sperling P, Becker A, Bornath T, Bredow R, Döppner T, Dziarzhytski S, Fennel T, Fletcher LB, Förster E, Fortmann C, Glenzer SH, Göde S, Gregori G, Harmand M, Hilbert V, Holst B, Laarmann T, Lee HJ, Ma T, Mithen JP, Mitzner R, Murphy CD, Nakatsutsumi M, Neumayer P, Przystawik A, Roling S, Schulz M, Siemer B, Skruszewicz S, Tiggesbäumker J, Toleikis S, Tschentscher T, White T, Wöstmann M, Zacharias H, Redmer R. Equilibration dynamics and conductivity of warm dense hydrogen. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:013104. [PMID: 25122398 DOI: 10.1103/physreve.90.013104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Indexed: 06/03/2023]
Abstract
We investigate subpicosecond dynamics of warm dense hydrogen at the XUV free-electron laser facility (FLASH) at DESY (Hamburg). Ultrafast impulsive electron heating is initiated by a ≤ 300-fs short x-ray burst of 92-eV photon energy. A second pulse probes the sample via x-ray scattering at jitter-free variable time delay. We show that the initial molecular structure dissociates within (0.9 ± 0.2) ps, allowing us to infer the energy transfer rate between electrons and ions. We evaluate Saha and Thomas-Fermi ionization models in radiation hydrodynamics simulations, predicting plasma parameters that are subsequently used to calculate the static structure factor. A conductivity model for partially ionized plasma is validated by two-temperature density-functional theory coupled to molecular dynamic simulations and agrees with the experimental data. Our results provide important insights and the needed experimental data on transport properties of dense plasmas.
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66
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Döppner T, Kritcher AL, Kraus D, Glenzer SH, Bachmann BL, Chapman D, Collins GW, Falcone RW, Hawreliak J, Landen OL, Lee HJ, Pape SL, Ma T, Neumayer P, Redmer R, Swift DC. X-ray Thomson scattering as a temperature probe for Gbar shock experiments. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/500/19/192019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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67
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Fletcher LB, Kritcher AL, Pak A, Ma T, Döppner T, Fortmann C, Divol L, Jones OS, Landen OL, Scott HA, Vorberger J, Chapman DA, Gericke DO, Mattern BA, Seidler GT, Gregori G, Falcone RW, Glenzer SH. Observations of continuum depression in warm dense matter with x-ray Thomson scattering. PHYSICAL REVIEW LETTERS 2014; 112:145004. [PMID: 24765979 DOI: 10.1103/physrevlett.112.145004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Indexed: 06/03/2023]
Abstract
Detailed measurements of the electron densities, temperatures, and ionization states of compressed CH shells approaching pressures of 50 Mbar are achieved with spectrally resolved x-ray scattering. Laser-produced 9 keV x-rays probe the plasma during the transient state of three-shock coalescence. High signal-to-noise x-ray scattering spectra show direct evidence of continuum depression in highly degenerate warm dense matter states with electron densities ne>1024 cm-3. The measured densities and temperatures agree well with radiation-hydrodynamic modeling when accounting for continuum lowering in calculations that employ detailed configuration accounting.
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68
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Zastrau U, Sperling P, Harmand M, Becker A, Bornath T, Bredow R, Dziarzhytski S, Fennel T, Fletcher LB, Förster E, Göde S, Gregori G, Hilbert V, Hochhaus D, Holst B, Laarmann T, Lee HJ, Ma T, Mithen JP, Mitzner R, Murphy CD, Nakatsutsumi M, Neumayer P, Przystawik A, Roling S, Schulz M, Siemer B, Skruszewicz S, Tiggesbäumker J, Toleikis S, Tschentscher T, White T, Wöstmann M, Zacharias H, Döppner T, Glenzer SH, Redmer R. Resolving ultrafast heating of dense cryogenic hydrogen. PHYSICAL REVIEW LETTERS 2014; 112:105002. [PMID: 24679300 DOI: 10.1103/physrevlett.112.105002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Indexed: 06/03/2023]
Abstract
We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a ≲300 fs, 92 eV free electron laser x-ray burst. The rise of the x-ray scattering amplitude from a second x-ray pulse probes the transition from dense cryogenic molecular hydrogen to a nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time of ∼0.9 ps. The rise time agrees with radiation hydrodynamics simulations based on a conductivity model for partially ionized plasma that is validated by two-temperature density-functional theory.
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69
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Albert F, Pollock BB, Shaw JL, Marsh KA, Ralph JE, Chen YH, Alessi D, Pak A, Clayton CE, Glenzer SH, Joshi C. Angular dependence of betatron x-ray spectra from a laser-wakefield accelerator. PHYSICAL REVIEW LETTERS 2013; 111:235004. [PMID: 24476282 DOI: 10.1103/physrevlett.111.235004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Indexed: 06/03/2023]
Abstract
We present the first measurements of the angular dependence of the betatron x-ray spectrum produced by electrons inside the cavity of a laser-wakefield accelerator. Electrons accelerated up to 300 MeV energies produce a beam of broadband, forward-directed betatron x-ray radiation extending up to 80 keV. The angular resolved spectrum from an image plate-based spectrometer with differential filtering provides data in a single laser shot. The simultaneous spectral and spatial x-ray analysis allows for a three-dimensional reconstruction of electron trajectories with micrometer resolution, and we find that the angular dependence of the x-ray spectrum is showing strong evidence of anisotropic electron trajectories.
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70
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Dewald EL, Milovich JL, Michel P, Landen OL, Kline JL, Glenn S, Jones O, Kalantar DH, Pak A, Robey HF, Kyrala GA, Divol L, Benedetti LR, Holder J, Widmann K, Moore A, Schneider MB, Döppner T, Tommasini R, Bradley DK, Bell P, Ehrlich B, Thomas CA, Shaw M, Widmayer C, Callahan DA, Meezan NB, Town RPJ, Hamza A, Dzenitis B, Nikroo A, Moreno K, Van Wonterghem B, Mackinnon AJ, Glenzer SH, MacGowan BJ, Kilkenny JD, Edwards MJ, Atherton LJ, Moses EI. Early-time symmetry tuning in the presence of cross-beam energy transfer in ICF experiments on the National Ignition Facility. PHYSICAL REVIEW LETTERS 2013; 111:235001. [PMID: 24476279 DOI: 10.1103/physrevlett.111.235001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Indexed: 06/03/2023]
Abstract
On the National Ignition Facility, the hohlraum-driven implosion symmetry is tuned using cross-beam energy transfer (CBET) during peak power, which is controlled by applying a wavelength separation between cones of laser beams. In this Letter, we present early-time measurements of the instantaneous soft x-ray drive at the capsule using reemission spheres, which show that this wavelength separation also leads to significant CBET during the first shock, even though the laser intensities are 30× smaller than during the peak. We demonstrate that the resulting early drive P2/P0 asymmetry can be minimized and tuned to <1% accuracy (well within the ±7.5% requirement for ignition) by varying the relative input powers between different cones of beams. These experiments also provide time-resolved measurements of CBET during the first 2 ns of the laser drive, which are in good agreement with radiation-hydrodynamics calculations including a linear CBET model.
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71
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Smalyuk VA, Atherton LJ, Benedetti LR, Bionta R, Bleuel D, Bond E, Bradley DK, Caggiano J, Callahan DA, Casey DT, Celliers PM, Cerjan CJ, Clark D, Dewald EL, Dixit SN, Döppner T, Edgell DH, Edwards MJ, Frenje J, Gatu-Johnson M, Glebov VY, Glenn S, Glenzer SH, Grim G, Haan SW, Hammel BA, Hartouni EP, Hatarik R, Hatchett S, Hicks DG, Hsing WW, Izumi N, Jones OS, Key MH, Khan SF, Kilkenny JD, Kline JL, Knauer J, Kyrala GA, Landen OL, Le Pape S, Lindl JD, Ma T, MacGowan BJ, Mackinnon AJ, MacPhee AG, McNaney J, Meezan NB, Moody JD, Moore A, Moran M, Moses EI, Pak A, Parham T, Park HS, Patel PK, Petrasso R, Ralph JE, Regan SP, Remington BA, Robey HF, Ross JS, Spears BK, Springer PT, Suter LJ, Tommasini R, Town RP, Weber SV, Widmann K. Performance of high-convergence, layered DT implosions with extended-duration pulses at the National Ignition Facility. PHYSICAL REVIEW LETTERS 2013; 111:215001. [PMID: 24313493 DOI: 10.1103/physrevlett.111.215001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Indexed: 06/02/2023]
Abstract
Radiation-driven, low-adiabat, cryogenic DT layered plastic capsule implosions were carried out on the National Ignition Facility (NIF) to study the sensitivity of performance to peak power and drive duration. An implosion with extended drive and at reduced peak power of 350 TW achieved the highest compression with fuel areal density of ~1.3±0.1 g/cm2, representing a significant step from previously measured ~1.0 g/cm2 toward a goal of 1.5 g/cm2. Future experiments will focus on understanding and mitigating hydrodynamic instabilities and mix, and improving symmetry required to reach the threshold for thermonuclear ignition on NIF.
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Meezan NB, Hicks DG, Callahan DA, Olson RE, Schneider MS, Thomas CA, Robey HF, Celliers PM, Kline JL, Dixit SN, Michel PA, Jones OS, Clark DS, Ralph JE, Döppner T, MacKinnon AJ, Haan SW, Landen OL, Glenzer SH, Suter LJ, Edwards MJ, MacGowan BJ, Lindl JD, Atherton LJ. Hohlraum designs for high velocity implosions on NIF. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20135902002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ma T, Patel PK, Izumi N, Springer PT, Key MH, Atherton LJ, Benedetti LR, Bradley DK, Callahan DA, Celliers PM, Cerjan CJ, Clark DS, Dewald EL, Dixit SN, Döppner T, Edgell DH, Epstein R, Glenn S, Grim G, Haan SW, Hammel BA, Hicks D, Hsing WW, Jones OS, Khan SF, Kilkenny JD, Kline JL, Kyrala GA, Landen OL, Le Pape S, MacGowan BJ, Mackinnon AJ, MacPhee AG, Meezan NB, Moody JD, Pak A, Parham T, Park HS, Ralph JE, Regan SP, Remington BA, Robey HF, Ross JS, Spears BK, Smalyuk V, Suter LJ, Tommasini R, Town RP, Weber SV, Lindl JD, Edwards MJ, Glenzer SH, Moses EI. Onset of hydrodynamic mix in high-velocity, highly compressed inertial confinement fusion implosions. PHYSICAL REVIEW LETTERS 2013; 111:085004. [PMID: 24010449 DOI: 10.1103/physrevlett.111.085004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Indexed: 06/02/2023]
Abstract
Deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility have demonstrated yields ranging from 0.8 to 7×10(14), and record fuel areal densities of 0.7 to 1.3 g/cm2. These implosions use hohlraums irradiated with shaped laser pulses of 1.5-1.9 MJ energy. The laser peak power and duration at peak power were varied, as were the capsule ablator dopant concentrations and shell thicknesses. We quantify the level of hydrodynamic instability mix of the ablator into the hot spot from the measured elevated absolute x-ray emission of the hot spot. We observe that DT neutron yield and ion temperature decrease abruptly as the hot spot mix mass increases above several hundred ng. The comparison with radiation-hydrodynamic modeling indicates that low mode asymmetries and increased ablator surface perturbations may be responsible for the current performance.
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Regan SP, Epstein R, Hammel BA, Suter LJ, Scott HA, Barrios MA, Bradley DK, Callahan DA, Cerjan C, Collins GW, Dixit SN, Döppner T, Edwards MJ, Farley DR, Fournier KB, Glenn S, Glenzer SH, Golovkin IE, Haan SW, Hamza A, Hicks DG, Izumi N, Jones OS, Kilkenny JD, Kline JL, Kyrala GA, Landen OL, Ma T, MacFarlane JJ, MacKinnon AJ, Mancini RC, McCrory RL, Meezan NB, Meyerhofer DD, Nikroo A, Park HS, Ralph J, Remington BA, Sangster TC, Smalyuk VA, Springer PT, Town RPJ. Hot-spot mix in ignition-scale inertial confinement fusion targets. PHYSICAL REVIEW LETTERS 2013; 111:045001. [PMID: 23931375 DOI: 10.1103/physrevlett.111.045001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 04/04/2013] [Indexed: 06/02/2023]
Abstract
Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. Low neutron yields and hot-spot mix mass between 34(-13,+50) ng and 4000(-2970,+17 160) ng are observed.
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Moody JD, Strozzi DJ, Divol L, Michel P, Robey HF, LePape S, Ralph J, Ross JS, Glenzer SH, Kirkwood RK, Landen OL, MacGowan BJ, Nikroo A, Williams EA. Raman backscatter as a remote laser power sensor in high-energy-density plasmas. PHYSICAL REVIEW LETTERS 2013; 111:025001. [PMID: 23889410 DOI: 10.1103/physrevlett.111.025001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Indexed: 06/02/2023]
Abstract
Stimulated Raman backscatter is used as a remote sensor to quantify the instantaneous laser power after transfer from outer to inner cones that cross in a National Ignition Facility (NIF) gas-filled hohlraum plasma. By matching stimulated Raman backscatter between a shot reducing outer versus a shot reducing inner power we infer that about half of the incident outer-cone power is transferred to inner cones, for the specific time and wavelength configuration studied. This is the first instantaneous nondisruptive measure of power transfer in an indirect drive NIF experiment using optical measurements.
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