Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleKanel GI, Garkushin GV, Savinykh AS, et al., 2014,
Shock response of magnesium single crystals at normal and elevated temperatures
, Journal of Applied Physics, Vol: 116, Pages: 1-9, ISSN: 0021-8979A series of magnesium single crystals, from 0.2 to 3 mm thick, were shock loaded in directions parallel and perpendicular to the c-axis of the hexagonal closed packed (hcp) structure and at 45° to the c-axis. Shock compression along the c-axis is associated with the largest Hugoniot elastic limit (HEL) for this material. Microscopic observation of recovered c-cut samples demonstrated intense twinning with a greater density of twins near the impact surface. The low-energy basal slip was activated by shock loading along the inclined direction and has the smallest HEL. In all cases, we observe the decay of the elastic precursor wave and growth of the HEL with increasing temperature. For the inclined shock compression after the HEL, two plastic waves were found where the stress level of the first plastic wave depends on the peak shock stress. Finally, the largest spall strength was along the transversal direction and the smallest in the off-axis direction. The fracture surface of the sample of transversal orientation contains numerous groves oriented along the base planes of the crystals.
-
Journal articleTunnell R, Ashcroft M, Dale R, et al., 2014,
Ammonium Perchlorate, Friend or Foe?
, PROPELLANTS EXPLOSIVES PYROTECHNICS, Vol: 39, Pages: 707-713, ISSN: 0721-3115- Author Web Link
- Cite
- Citations: 2
-
Journal articleTurrell AE, Sherlock M, Rose SJ, 2014,
Effects of Large-Angle Coulomb Collisions on Inertial Confinement Fusion Plasmas (vol 112, 245002, 2014)
, PHYSICAL REVIEW LETTERS, Vol: 113, ISSN: 0031-9007 -
Journal articleTunnell R, Ashcroft M, Dale R, et al., 2014,
Ammonium Perchlorate, Friend or Foe? Part 1: The Influence of this Oxidizer on the Aging Behavior of Propellant Compositions
, PROPELLANTS EXPLOSIVES PYROTECHNICS, Vol: 39, Pages: 504-510, ISSN: 0721-3115- Author Web Link
- Cite
- Citations: 3
-
Journal articleHill EG, Rose SJ, 2014,
Non-thermal enhancement of electron-positron pair creation in burning thermonuclear laboratory plasmas
, High Energy Density Physics -
Journal articleHall GN, Burdiak GC, Suttle L, et al., 2014,
Monochromatic radiography of high energy density physics experiments on the MAGPIE generator
, Review of Scientific Instruments, Vol: 85, ISSN: 1089-7623A monochromatic X-ray backlighter based on Bragg reflection from a spherically bent quartzcrystal has been developed for the MAGPIE pulsed power generator at Imperial College (1.4 MA,240 ns) [I. H. Mitchell et al., Rev. Sci. Instrum. 67, 1533 (2005)]. This instrument has been usedto diagnose high energy density physics experiments with 1.865 keV radiation (Silicon He-α) froma laser plasma source driven by a ∼7 J, 1 ns pulse from the Cerberus laser. The design of thediagnostic, its characterisation and performance, and initial results in which the instrument was usedto radiograph a shock physics experiment on MAGPIE are discussed.
-
Journal articleTurrell AE, Rose SJ, Sherlock M, 2014,
Effects of Large-Angle Coulomb Collisions on Inertial Confinement Fusion Plasmas
, Physical Review Letters, Vol: 112Large-angle Coulomb collisions affect the rates of energy and momentum exchange in a plasma, and it is expected that their effects will be important in many plasmas of current research interest, including in inertial confinement fusion. Their inclusion is a long-standing problem, and the first fully self-consistent method for calculating their effects is presented. This method is applied to “burn” in the hot fuel in inertial confinement fusion capsules and finds that the yield increases due to an increase in the rate of temperature equilibration between electrons and ions which is not predicted by small-angle collision theories. The equilibration rate increases are 50%–100% for number densities of 10^{30} m^{−3} and temperatures around1 keV.
-
Journal articlePike OJ, Mackenroth F, Hill EG, et al., 2014,
A photon-photon collider in a vacuum hohlraum
, Nature Photonics, Vol: 8, Pages: 434-436, ISSN: 1749-4885The ability to create matter from light is amongst the most striking predictions of quantum electrodynamics. Experimental signatures of this have been reported in the scattering of ultra-relativistic electron beams with laser beams1,2, intense laser–plasma interactions3 and laser-driven solid target scattering4. However, all such routes involve massive particles. The simplest mechanism by which pure light can be transformed into matter, Breit–Wheeler pair production (γγ′ → e+e−)5, has never been observed in the laboratory. Here, we present the design of a new class of photon–photon collider in which a gamma-ray beam is fired into the high-temperature radiation field of a laser-heated hohlraum. Matching experimental parameters to current-generation facilities, Monte Carlo simulations suggest that this scheme is capable of producing of the order of 105 Breit–Wheeler pairs in a single shot. This would provide the first realization of a pure photon–photon collider, representing the advent of a new type of high-energy physics experiment.
-
Journal articlePile D, Pike O, 2014,
Light into matter
, NATURE PHOTONICS, Vol: 8, Pages: 496-496, ISSN: 1749-4885 -
Journal articlePike OJ, Rose SJ, 2014,
Dynamical friction in a relativistic plasma
, PHYSICAL REVIEW E, Vol: 89, ISSN: 1539-3755- Author Web Link
- Cite
- Citations: 7
-
Journal articleLebedev SV, Suttle L, Swadling GF, et al., 2014,
The formation of reverse shocks in magnetized high energy density supersonic plasma flows
, PHYSICS OF PLASMAS, Vol: 21, ISSN: 1070-664X- Author Web Link
- Cite
- Citations: 30
-
Journal articleKeenan FP, Doyle JG, Madjarska MS, et al., 2014,
INTENSITY ENHANCEMENT OF O VI ULTRAVIOLET EMISSION LINES IN SOLAR SPECTRA DUE TO OPACITY
, ASTROPHYSICAL JOURNAL LETTERS, Vol: 784, ISSN: 2041-8205- Author Web Link
- Cite
- Citations: 7
-
Conference paperNguyen TT, Davey T, Proud W, 2014,
Percolation of Gas and Attenuation of Shock Waves through Granular Beds and Perforated Sheets
, New Trends in Research of Energetic Materials -
Journal articleBurdiak GC, Lebedev SV, Harvey-Thompson AJ, et al., 2014,
Radiative precursors driven by converging blast waves in noble gases
, PHYSICS OF PLASMAS, Vol: 21, ISSN: 1070-664X- Author Web Link
- Cite
- Citations: 6
-
Journal articleTear GR, Eakins DE, Chapman DJ, et al., 2014,
Technique to measure change in birefringence under shock compression
, Journal of Physics: Conference Series, Vol: 500, ISSN: 1742-6588A technique has been developed to measure the change in birefringence along the axis of shock propagation, probing the relative refractive indices of the material perpendicular to shock propagation. Experiments were performed on calcite single crystals and the results compared to previous literature studies on calcite quasi-static behaviour. Interface velocities are determined using fibre based homodyne Photon Doppler Velocimetry (PDV) operating at 1550 nm whilst the birefringence technique uses free space 532 nm optics. A change in birefringence of Δn = 0.0029 ± 0.0001 was observed. This was higher than the predicted change found using a hydrostatic model based on previous studies.
-
Journal articleWinters JBR, Bland SN, Stafford SJP, et al., 2014,
VISAR 'cross-hairs': Simultaneous perpendicular line-imaging VISAR
, Journal of Physics: Conference Series, Vol: 500, ISSN: 1742-6588Often the velocity measured at the rear surface of a dynamic compression targetvaries spatially, caused for instance by the tilt/curvature of a gas gun flyer, asymmetries inthe magnetic field on a pulsed power driven experiment, or meso-scale heterogeneous targets.One way to monitor this in an experiment is to employ multiple point velocimetry techniques,but even with multiplexing this can become expensive in terms of hardware, in particular highspeed sensors and scope channels. We report on the initial development of a multi-axis lineimagingVISAR system, which will record the spatial velocity along two orthogonal directions.Cylindrical optics are used to project a set of cross-hairs onto the target, maximising the use ofinput laser light; we then describe the image relay, interferometer configuration and alignment.This ‘quasi’ two dimensional system will become one of the principal diagnostics on the MACH(Mega Ampere Compression and Hydrodynamics) facility at Imperial College London, where themulti-axis measurement will help optimise strip-line design to achieve uniform ramp compressionof targets.
-
Journal articleChapman DJ, Eakins DE, Proud WG, et al., 2014,
On the residual yield stress of shocked metals
, Journal of Physics: Conference Series, Vol: 500, ISSN: 1742-6588ffects of time and strain on material strength. With this objective, we performed a carefulcomparative measurement of the free-surface velocity of shock loaded aluminium AD1 andmagnesium alloy Ma2 samples of various thicknesses in the range 0.2 mm to 5 mm. Weobserved the expected decay in the elastic precursor state with increasing sample thicknessfor both aluminium and magnesium alloy. However, we also observed a small change in themagnitude of hysteresis in the elastic-plastic compression-unloading cycle; where qualitativelythe peak free-surface velocity also increased with increasing specimen thickness. Interestingly,the observed change in hysteresis as function of specimen thickness for the Ma2 alloy wasrelatively smaller than the AD1, in contrast with the larger change in precursor magnitudeobserved for the magnesium. We propose that softening due to multiplication of dislocations isrelatively large in Ma2 and results in a smaller hysteresis in the elastic-plastic cycle.
-
Conference paperWeinwurm M, Bland SN, Chittenden JP, 2014,
Metal liner-driven cylindrically convergent isentropic compression of cryogenic deuterium
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588 -
Conference paperBo C, Williams A, Rankin S, et al., 2014,
Integrated experimental platforms to study blast injuries: a bottom-up approach
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 4
-
Conference paperSuzuki-Vidal F, Lebedev SV, Ciardi A, et al., 2014,
Laboratory Astrophysics Experiments with Magnetically Driven Plasma Jets
, 15th International Congress on Plasma Physics (ICPP) / 13th Latin American Workshop on Plasma Physics (LAWPP), Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 2
-
Conference paperGarkushin GV, Savinykh AS, Kanel GI, et al., 2014,
Response of magnesium single crystals to shock-wave loading at room and elevated temperatures.
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 7
-
Conference paperWilgeroth JM, Nguyen T-TN, Proud WG, 2014,
Interaction between blast wave and reticulated foam: assessing the potential for auditory protection systems
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 1
-
Conference paperKhan AS, Balzer JE, Wilgeroth JM, et al., 2014,
Temperature effects on the mechanical behaviour of PZT 95/5
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 5
-
Conference paperButler BJ, Bo C, Tucker AW, et al., 2014,
Mechanical and histological characterization of trachea tissue subjected to blast-type pressures
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 3
-
Conference paperProud WG, 2014,
Gas percolation through sand
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 1
-
Conference paperKhan AS, Balzer JE, Wilgeroth JM, et al., 2014,
Aspect ratio compression effects on metals and polymers
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 6
-
Conference paperNguyen T-TN, Wilgeroth JM, Proud WG, 2014,
Controlling blast wave generation in a shock tube for biological applications
, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588- Author Web Link
- Cite
- Citations: 20
-
Journal articleSuzuki Vidal F, Patankar S, Lebedev SV, et al., 2013,
Observation of energetic protons trapped in laboratory magnetic-tower jets
, New Journal of Physics, Vol: 15, ISSN: 1367-2630Preliminary results of the self-emission of charged particles frommagnetically driven plasma jets has been investigated. The jets were launchedand driven by a toroidal magnetic field generated by introducing a ∼1.4 MA,250 ns electrical current pulse from the MAGPIE generator into a radialwire array. This configuration has shown to reproduce some aspects of theastrophysical magnetic-tower jet launching model, in which a jet is collimatedby a toroidal magnetic field inside a magnetic cavity. The emission of ions andprotons from the plasma was recorded onto Columbia Resin 39 plates using timeintegratedpinhole cameras. In addition a fly-eye camera, an array of 25–496cylindrical apertures allowed estimating the location of the ion emitting source.The results show the ion emission comes from both the jet and its surroundingmagnetic cavity, with the emission extending to a height of at least ∼9 cm fromthe initial position of the wires. The emission of ions is consistent with the dynamics of the jet obtained from time-resolved imaging diagnostics, i.e. opticallaser probing and self-emission of the plasma in the extreme ultra-violet. Thesepreliminary results suggest the ions are trapped inside the cavity due to the strongtoroidal magnetic field which drives the jet. In addition these studies providefirst estimates of the energy and fluence of protons for future laser-driven protonprobing diagnostics aimed at measuring the magnetic field in these experiments.
-
Journal articleTurrell AE, Sherlock M, Rose SJ, 2013,
A Monte Carlo algorithm for degenerate plasmas
, JOURNAL OF COMPUTATIONAL PHYSICS, Vol: 249, Pages: 13-21, ISSN: 0021-9991- Author Web Link
- Cite
- Citations: 7
-
Journal articleScott RHH, Perez F, Streeter MJV, et al., 2013,
Fast electron beam measurements from relativistically intense, frequency-doubled laser-solid interactions
, NEW JOURNAL OF PHYSICS, Vol: 15, ISSN: 1367-2630- Author Web Link
- Cite
- Citations: 5
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.
Publications Archive
View the ISP Publications Archive