Publications


An investigation of the L-shell X-ray conversion efficiency for laser-irradiated tin foils

Plasma Science and Technology IOP Publishing (0)

D Bailie, C Hyland, R Singh, S White, G Sarri, F Keenan, D Riley, S Rose, E Hill, F Wang, D Yuan, G Zhao, H Wei, B Han, B Zhu, J Zhu, P Yang


Modified Friedmann equations via conformal Bohm -- De Broglie gravity

The Astrophysical Journal: an international review of astronomy and astronomical physics American Astronomical Society (0)

G Gregori, B Reville, B Larder

We use an alternative interpretation of quantum mechanics, based on the Bohmian trajectory approach, and show that the quantum effects can be included in the classical equation of motion via a conformal transformation on the background metric. We apply this method to the Robertson-Walker metric to derive a modified version of Friedmann's equations for a Universe consisting of scalar, spin-zero, massive particles. These modified equations include additional terms that result from the non-local nature of matter and appear as an acceleration in the expansion of the Universe. We see that the same effect may also be present in the case of an inhomogeneous expansion.


Fast Non-Adiabatic Dynamics of Many-Body Quantum Systems

Science Advances Springer Verlag (0)

B Larder, D Gericke, S Richardson, P Mabey, T White, G Gregori

Modeling many-body quantum systems with strong interactions is one of the core challenges of modern physics. A range of methods has been developed to approach this task, each with its own idiosyncrasies, approximations, and realm of applicability. Perhaps the most successful and ubiquitous of these approaches is density functional theory (DFT). Its Kohn-Sham formulation has been the basis for many fundamental physical insights, and it has been successfully applied to fields as diverse as quantum chemistry, condensed matter and dense plasmas. Despite the progress made by DFT and related schemes, however, there remain many problems that are intractable for existing methods. In particular, many approaches face a huge computational barrier when modeling large numbers of coupled electrons and ions at finite temperature. Here, we address this shortfall with a new approach to modeling many-body quantum systems. Based on the Bohmian trajectories formalism, our new method treats the full particle dynamics with a considerable increase in computational speed. As a result, we are able to perform large-scale simulations of coupled electron-ion systems without employing the adiabatic Born-Oppenheimer approximation.


Vibrational excitation induced by electron beam and cosmic rays in normal and superconductive aluminum bars

ArXiv (0)

M Bassan, B Buonomo, G Cavallari, E Coccia, S D'Antonio, V Fafone, LG Foggetta, C Ligi, A Marini, G Mazzitelli, G Modestino, G Pizzella, L Quintieri, F Ronga, P Valente, SM Vinko

We report new measurements of the acoustic excitation of an Al5056 superconductive bar when hit by an electron beam, in a previously unexplored temperature range, down to 0.35 K. These data, analyzed together with previous results of the RAP experiment obtained for T > 0.54 K, show a vibrational response enhanced by a factor 4.9 with respect to that measured in the normal state. This enhancement explains the anomalous large signals due to cosmic rays previously detected in the NAUTILUS gravitational wave detector.


Experimental study of high energy electron interactions in a superconducting aluminum alloy resonant bar

ArXiv (0)

M Barucci, M Bassan, B Buonomo, G Cavallari, E Coccia, S D'Antonio, V Fafone, C Ligi, L Lolli, A Marini, G Mazzitelli, G Modestino, G Pizzella, L Quintieri, L Risegari, A Rocchi, F Ronga, P Valente, G Ventura, SM Vinko

Peak amplitude measurements of the fundamental mode of oscillation of a suspended aluminum alloy bar hit by an electron beam show that the amplitude is enhanced by a factor ~3.5 when the material is in the superconducting state. This result is consistent with the cosmic ray observations made by the resonant gravitational wave detector NAUTILUS, made of the same alloy, when operated in the superconducting state. A comparison of the experimental data with the predictions of the model describing the underlying physical process is also presented.


XUV Opacity of Aluminum between the Cold-Solid to Warm-Plasma Transition

High Energy Density Physics Elsevier BV (2009)

SM Vinko, G Gregori, B Nagler, TJ Whitcher, MP Desjarlais, RW Lee, P Audebert, JS Wark

We present calculations of the free-free XUV opacity of warm, solid-density aluminum at photon energies between the plasma frequency at 15 eV and the L-edge at 73 eV, using both density functional theory combined with molecular dynamics and a semi-analytical model in the RPA framework with the inclusion of local field corrections. As the temperature is increased from room temperature to 10 eV, with the ion and electron temperatures equal, we calculate an increase in the opacity in the range over which the degree of ionization is constant. The effect is less pronounced if only the electron temperature is allowed to increase. The physical significance of these increases is discussed in terms of intense XUV-laser matter interactions on both femtosecond and picosecond time-scales.


Explanations for the observed increase in fast electron penetration in laser shock compressed materials

Physical Review E American Physical Society (APS) 61 (0) 5725-5733

D Batani, JR Davies, A Bernardinello, F Pisani, M Koenig, TA Hall, S Ellwi, P Norreys, S Rose, A Djaoui, D Neely


Single-Shot Multi-keV X-Ray Absorption Spectroscopy Using an Ultrashort Laser-Wakefield Accelerator Source

Physical Review Letters American Physical Society (APS) 123 (0) 254801

B Kettle, E Gerstmayr, MJV Streeter, F Albert, RA Baggott, N Bourgeois, JM Cole, S Dann, K Falk, I Gallardo González, AE Hussein, N Lemos, NC Lopes, O Lundh, Y Ma, SJ Rose, C Spindloe, DR Symes, M Šmíd, AGR Thomas, R Watt, SPD Mangles


The Role of Collisionality and Radiative Cooling in Supersonic Plasma Jet Collisions of Different Materials

Physical Review E: Statistical, Nonlinear, and Soft Matter Physics American Physical Society (0)

G GREGORI


Ab initio simulations and measurements of the free-free opacity in Aluminum

Physical Review E American Physical Society (0)

JUSTIN WARK


How to control the laser emission in single longitudinal mode

Optica Pura y Aplicada Sociedad Espanola de Optica 48 (0) 141-144

V Gonzalez-Fernandez, E Vasallo, G Perez, K Grutzmacher, LM Fuentes, C Perez, MI de la Rosa


Nonlinear crystals: are they magic?

Optica Pura y Aplicada Sociedad Espanola de Optica 48 (0) 135-139

V Gonzalez-Fernandez, G Perez, E Vasallo, K Grutzmacher, LM Fuentes, C Perez, MI de la Rosa


Sherlocket al.Reply:

Physical Review Letters American Physical Society (APS) 116 (0) 159502

M Sherlock, W Rozmus, EG Hill, SJ Rose


Experimental characterization of the interaction zone between counter propagating Taylor Sedov blast waves

Physics of Plasmas AIP Publishing (0)

G GREGORI

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