Publications


Prospects for Multi kJ plasma ampliefiers

Optics InfoBase Conference Papers Part F38-FiO 2016 (2014)

J Sadler, R Trines, L Ceurvorst, N Ratan, M Kasim, R Bingham, P Norreys

© OSA 2016.Plasma amplifiers potentially offer a route to low cost, high efficiency, multi-kJ, tunable laser pulses. I will describe numerical simulations underpinning careful experiment design and interpretation to optimize this process at the University of Rochester.


Compression of X-ray Free Electron Laser Pulses to Attosecond Duration.

Scientific reports 5 (2015) 16755-

JD Sadler, R Nathvani, P Oleśkiewicz, LA Ceurvorst, N Ratan, MF Kasim, RMGM Trines, R Bingham, PA Norreys

State of the art X-ray Free Electron Laser facilities currently provide the brightest X-ray pulses available, typically with mJ energy and several hundred femtosecond duration. Here we present one- and two-dimensional Particle-in-Cell simulations, utilising the process of stimulated Raman amplification, showing that these pulses are compressed to a temporally coherent, sub-femtosecond pulse at 8% efficiency. Pulses of this type may pave the way for routine time resolution of electrons in nm size potentials. Furthermore, evidence is presented that significant Landau damping and wave-breaking may be beneficial in distorting the rear of the interaction and further reducing the final pulse duration.


Imaging Shock Waves in Diamond with Both High Temporal and Spatial Resolution at an XFEL.

Scientific reports 5 (2015) 11089-

A Schropp, R Hoppe, V Meier, J Patommel, F Seiboth, Y Ping, DG Hicks, MA Beckwith, GW Collins, A Higginbotham, JS Wark, HJ Lee, B Nagler, EC Galtier, B Arnold, U Zastrau, JB Hastings, CG Schroer

The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range, and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by using the short XFEL pulse to image an elastic compression wave in diamond. The elastic wave was initiated by an intense optical laser pulse and was imaged at different delay times after the optical pump pulse using magnified x-ray phase-contrast imaging. The temporal evolution of the shock wave can be monitored, yielding detailed information on shock dynamics, such as the shock velocity, the shock front width, and the local compression of the material. The method provides a quantitative perspective on the state of matter in extreme conditions.


Generation of high-flux neutron beam from radiation pressure driven deuterium ion bunches

42nd European Physical Society Conference on Plasma Physics, EPS 2015 (2015)

A Alejo, S Kar, H Ahmed, AG Krygier, R Clarke, RR Freeman, J Fuchs, A Green, JS Green, D Jung, A Kleinschmidt, JT Morrison, Z Najmudin, H Nakamura, P Norreys, M Notley, M Oliver, M Roth, L Vassura, M Zepf, M Borghesi


Pellet ignition using ions shock accelerated in the corona

42nd European Physical Society Conference on Plasma Physics, EPS 2015 (2015)

RA Cairns, E Boella, M Vranic, LO Silva, R Trines, P Norreys, R Bingham


The creation of large-volume, gradient-free warm dense matter with an x-ray free-electron laser

Physics of Plasmas 22 (2015)

A Lévy, P Audebert, R Shepherd, J Dunn, M Cammarata, O Ciricosta, F Deneuville, F Dorchies, M Fajardo, C Fourment, D Fritz, J Fuchs, J Gaudin, M Gauthier, A Graf, HJ Lee, H Lemke, B Nagler, J Park, O Peyrusse, AB Steel, SM Vinko, JS Wark, GO Williams, D Zhu, RW Lee

© 2015 AIP Publishing LLC. The efficiency and uniformity of heating induced by hard x-ray free-electron laser pulse is investigated for 0.5 μm silver foils using the X-ray Pump Probe instrument at the Linac Coherent Light Source facility. Intense 8.9 keV x-ray pulses of 60fs duration deposit energy predominantly via inner-shell ionization to create a non-equilibrium Ag solid density plasma. The x-ray pulses are focused to 14 × 17 μm2 by means of beryllium lenses and by varying the total beam energy, the energy deposition is varied over a range of irradiances from 4.4 to 6.5 × 1015 ∼ W/cm2. Two time-and-space resolved interferometers simultaneously probed the expansion of the front and rear sample surfaces and find evidence of a nearly symmetric expansion pointing to the uniformity of energy deposition over the full target thickness. The experimental results are compared with two different hydrodynamic simulations of the sample expansion. The agreement between experimental and theoretical results yields an estimate of the temperature evolution as a function of x-ray irradiance that varies from 8 to 10 eV for the x-ray irradiances studied.


Observation of finite-wavelength screening in high-energy-density matter.

Nature communications 6 (2015) 6839-

DA Chapman, J Vorberger, LB Fletcher, RA Baggott, L Divol, T Döppner, RW Falcone, SH Glenzer, G Gregori, TM Guymer, AL Kritcher, OL Landen, T Ma, AE Pak, DO Gericke

A key component for the description of charged particle systems is the screening of the Coulomb interaction between charge carriers. First investigated in the 1920s by Debye and Hückel for electrolytes, charge screening is important for determining the structural and transport properties of matter as diverse as astrophysical and laboratory plasmas, nuclear matter such as quark-gluon plasmas, electrons in solids, planetary cores and charged macromolecules. For systems with negligible dynamics, screening is still mostly described using a Debye-Hückel-type approach. Here, we report the novel observation of a significant departure from the Debye-Hückel-type model in high-energy-density matter by probing laser-driven, shock-compressed plastic with high-energy X-rays. We use spectrally resolved X-ray scattering in a geometry that enables direct investigation of the screening cloud, and demonstrate that the observed elastic scattering amplitude is only well described within a more general approach.


Quantitative single shot and spatially resolved plasma wakefield diagnostics

Physical Review Special Topics: Accelerators and Beams American Physical Society 18 (2015)

M Kasim, J Holloway, L Ceurvorst, MC Levy, N Ratan, R Bingham, J Sadler, P Burrows, M Wing, R Trines, P Norreys

Diagnosing plasma conditions can give great advantages in optimizing plasma wakefield accelerator experiments. One possible method is that of photon acceleration. By propagating a laser probe pulse through a plasma wakefield and extracting the imposed frequency modulation, one can obtain an image of the density modulation of the wakefield. In order to diagnose the wakefield parameters at a chosen point in the plasma, the probe pulse crosses the plasma at oblique angles relative to the wakefield. In this paper, mathematical expressions relating the frequency modulation of the laser pulse and the wakefield density profile of the plasma for oblique crossing angles are derived. Multidimensional particle-in-cell simulation results presented in this paper confirm that the frequency modulation profiles and the density modulation profiles agree to within 10%. Limitations to the accuracy of the measurement are discussed in this paper. This technique opens new possibilities to quantitatively diagnose the plasma wakefield density at known positions within the plasma column.


Enhanced proton beam collimation in the ultra-intense short pulse regime

PLASMA PHYSICS AND CONTROLLED FUSION 56 (2014) ARTN 084001

JS Green, NP Dover, M Borghesi, CM Brenner, FH Cameron, DC Carroll, PS Foster, P Gallegos, G Gregori, P McKenna, CD Murphy, Z Najmudin, CAJ Palmer, R Prasad, L Romagnani, KE Quinn, J Schreiber, MJV Streeter, S Ter-Avetisyan, O Tresca, M Zepf, D Neely


Nanosecond Imaging of Shock- and Jet-Like Features

IEEE TRANSACTIONS ON PLASMA SCIENCE 42 (2014) 2496-2497

ER Tubman, R Crowston, R Alraddadi, HW Doyle, J Meinecke, JE Cross, R Bolis, D Lamb, P Tzeferacos, D Doria, B Reville, H Ahmed, M Borghesi, G Gregori, NC Woolsey


SCALING OF MAGNETO-QUANTUM-RADIATIVE HYDRODYNAMIC EQUATIONS: FROM LASER-PRODUCED PLASMAS TO ASTROPHYSICS

ASTROPHYSICAL JOURNAL 795 (2014) ARTN 59

JE Cross, B Reville, G Gregori


Quantum theory of Thomson scattering

HIGH ENERGY DENSITY PHYSICS 13 (2014)

BJB Crowley, G Gregori


Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

PLASMA PHYSICS AND CONTROLLED FUSION 56 (2014) ARTN 084013

R Assmann, R Bingham, T Bohl, C Bracco, B Buttenschoen, A Butterworth, A Caldwell, S Chattopadhyay, S Cipiccia, E Feldbaumer, RA Fonseca, B Goddard, M Gross, O Grulke, E Gschwendtner, J Holloway, C Huang, D Jaroszynski, S Jolly, P Kempkes, N Lopes, K Lotov, J Machacek, SR Mandry, JW McKenzie, M Meddahi, BL Militsyn, N Moschuering, P Muggli, Z Najmudin, TCQ Noakes, PA Norreys, E Oez, A Pardons, A Petrenko, A Pukhov, K Rieger, O Reimann, H Ruhl, E Shaposhnikova, LO Silva, A Sosedkin, R Tarkeshian, RMGN Trines, T Tueckmantel, J Vieira, H Vincke, M Wing, G Xia


Equilibration dynamics and conductivity of warm dense hydrogen.

Physical review. E, Statistical, nonlinear, and soft matter physics 90 (2014) 013104-

U Zastrau, P Sperling, A Becker, T Bornath, R Bredow, T Döppner, S Dziarzhytski, T Fennel, LB Fletcher, E Förster, C Fortmann, SH Glenzer, S Göde, G Gregori, M Harmand, V Hilbert, B Holst, T Laarmann, HJ Lee, T Ma, JP Mithen, R Mitzner, CD Murphy, M Nakatsutsumi, P Neumayer, A Przystawik, S Roling, M Schulz, B Siemer, S Skruszewicz, J Tiggesbäumker, S Toleikis, T Tschentscher, T White, M Wöstmann, H Zacharias, R Redmer

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.


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 85 (2014) 11E702-

LB Fletcher, HJ Lee, B Barbrel, M Gauthier, E Galtier, B Nagler, T Döppner, S LePape, T Ma, A Pak, D Turnbull, T White, G Gregori, M Wei, RW Falcone, P Heimann, U Zastrau, JB Hastings, SH Glenzer

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.


Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers.

The Review of scientific instruments 85 (2014) 093303-

A Alejo, S Kar, H Ahmed, AG Krygier, D Doria, R Clarke, J Fernandez, RR Freeman, J Fuchs, A Green, JS Green, D Jung, A Kleinschmidt, CLS Lewis, JT Morrison, Z Najmudin, H Nakamura, G Nersisyan, P Norreys, M Notley, M Oliver, M Roth, JA Ruiz, L Vassura, M Zepf, M Borghesi

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C(6+), O(8+), etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.


Equilibration dynamics and conductivity of warm dense hydrogen

PHYSICAL REVIEW E 90 (2014) ARTN 013104

U Zastrau, P Sperling, A Becker, T Bornath, R Bredow, T Doeppner, S Dziarzhytski, T Fennel, LB Fletcher, E Forster, C Fortmann, SH Glenzer, S Goede, G Gregori, M Harmand, V Hilbert, B Holst, T Laarmann, HJ Lee, T Ma, JP Mithen, R Mitzner, CD Murphy, M Nakatsutsumi, P Neumayer, A Przystawik, S Roling, M Schulz, B Siemer, S Skruszewicz, J Tiggesbaeumker, S Toleikis, T Tschentscher, T White, M Woestmann, H Zacharias, R Redmer


Electron-phonon equilibration in laser-heated gold films

PHYSICAL REVIEW B 90 (2014) ARTN 014305

TG White, P Mabey, DO Gericke, NJ Hartley, HW Doyle, D McGonegle, DS Rackstraw, A Higginbotham, G Gregori


In-depth plasma-wave heating of dense plasma irradiated by short laser pulses.

Physical review letters 113 (2014) 255001-

M Sherlock, EG Hill, RG Evans, SJ Rose, W Rozmus

We investigate the mechanism by which relativistic electron bunches created at the surface of a target irradiated by a very short and intense laser pulse transfer energy to the deeper parts of the target. In existing theories, the dominant heating mechanism is that of resistive heating by the neutralizing return current. In addition to this, we find that large amplitude plasma waves are induced in the plasma in the wake of relativistic electron bunches. The subsequent collisional damping of these waves represents a source of heating that can exceed the resistive heating rate. As a result, solid targets heat significantly faster than has been previously considered. A new hybrid model, capable of reproducing these results, is described.


Non-thermal enhancement of electron-positron pair creation in burning thermonuclear laboratory plasmas

HIGH ENERGY DENSITY PHYSICS 13 (2014)

EG Hill, SJ Rose

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