Publications
Results
- Showing results for:
- Reset all filters
Search results
-
Conference paperButler BJ, Williams A, Tucker AW, et al., 2018,
Comparative quasi-static mechanical characterization of fresh and stored porcine trachea specimens
, 12th International Conference of the European-Association-for-the-Promotion-of-Research-into-the-Dynamic-Behaviour-of-Materials-and-its-Applications (DYMAT-Association), Publisher: SPRINGER HEIDELBERG, Pages: 55-60, ISSN: 1951-6355- Author Web Link
- Cite
- Citations: 2
-
Journal articleShelkovenko TA, Pikuz SA, Tilikin IN, et al., 2018,
X-pinch X-ray emission on a portable low-current, fast rise-time generator
, Journal of Applied Physics, Vol: 124, ISSN: 0021-8979We report on experiments exploring X-ray emission from an X-pinch driven by a small Marx-waterline generator supplying 50 kA with a risetime of 50 ns and a peak voltage of ∼250 kV. Both standard crossed wire loads and hybrid loads utilizing conical metal electrodes with a single short wire in between them were studied, and in both cases reliable modes of operation were obtained for X-ray radiography. Soft (few keV) and Hard (>5 keV) X-ray emission characteristics were observed. With standard X-pinches, soft radiation emanated from a small hot spot about 3 μm in size, along with hard radiation from a ∼200 μm region close to this hot spot. With hybrid X-pinches, the hot spot was <7 μm in size. There was a clear correlation between the soft and hard X-ray emission—pinches that produced intense soft X-ray emission from a small hot spot also produced the most intense, localized hard X-ray emission.
-
Journal articleWood JC, Chapman DJ, Poder K, et al., 2018,
Ultrafast imaging of laser driven shock waves using Betatron x-rays from a laser Wakefield accelerator
, Scientific Reports, Vol: 8, ISSN: 2045-2322Betatron radiation from laser wakefield accelerators is an ultrashort pulsedsource of hard, synchrotron-like x-ray radiation. It emanates from a centimetrescale plasma accelerator producing GeV level electron beams. In recent yearsbetatron radiation has been developed as a unique source capable of producinghigh resolution x-ray images in compact geometries. However, until now, theshort pulse nature of this radiation has not been exploited. This reportdetails the first experiment to utilise betatron radiation to image a rapidlyevolving phenomenon by using it to radiograph a laser driven shock wave in asilicon target. The spatial resolution of the image is comparable to what hasbeen achieved in similar experiments at conventional synchrotron light sources.The intrinsic temporal resolution of betatron radiation is below 100 fs,indicating that significantly faster processes could be probed in futurewithout compromising spatial resolution. Quantitative measurements of the shockvelocity and material density were made from the radiographs recorded duringshock compression and were consistent with the established shock response ofsilicon, as determined with traditional velocimetry approaches. This suggeststhat future compact betatron imaging beamlines could be useful in the imagingand diagnosis of high-energy-density physics experiments.
-
Conference paperSory DR, Amin HD, Rankin SM, et al., 2018,
Osteogenic Differentiation of Periosteum-Derived Stromal Cells in Blast-Associated Traumatic Loading
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Conference paperTear GR, Chapman DJ, Proud WG, et al., 2018,
The use of PDV to understand damage in rocket motor propellants
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AIP Publishing, ISSN: 1551-7616Photonic Doppler Velocimetry (PDV) has been fielded on small scale fragment impact experiments on double base propellant. A 130 mm block of propellant was impacted with a 20 mm diameter cylinder at 1003 ± 10 m s-1 and four PDV probes recorded rear surface motion at different radial distances between 10 mm and 60 mm from impact centre. The PDV was fielded alongside high speed video diagnostics using a dichroic mirror which reflected visible light whilst transmitting the 1550 nm wavelength which the PDV operated at. The rear surface velocity was compared to 2D numerical simulations of the experiment and found to be in good agreement. Additional material moving at up to 2 km s-1 was detected at break out.
-
Conference paperNguyen T-TN, Tear GR, Masouros SD, et al., 2018,
Fragment Penetrating Injury to Long Bones
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Conference paperSmith LC, Chapman DJ, Hooper PA, et al., 2018,
On the Dynamic Response of Additively Manufactured 316L
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Conference paperBrown KA, Butler BJ, Sory D, et al., 2018,
Challenges in the Characterization of Failure and Resilience of Biological Materials
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Conference paperOta TA, Chapman DJ, Richley JC, et al., 2018,
Initial Results From a Simultaneous Pyrometry and Reflectivity Diagnostic
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Journal articlede Grouchy PWL, Kusse BR, Banasek J, et al., 2018,
Observations of the magneto-Rayleigh-Taylor instability and shock dynamics in gas-puff Z-pinch experiments
, PHYSICS OF PLASMAS, Vol: 25, ISSN: 1070-664X -
Conference paperTear G, Cohen A, Magnus D, et al., 2018,
Damage characterisation for cement and concrete using microwave induced damage
, International Conference on Experimental Mechanics, Publisher: MDPI, ISSN: 2504-3900Damage leading to failure in concrete and related materials is a complex behavior. Whilst many numerical approaches are available for simulating the degradation of material strength, it is difficult to discriminate between these models experimentally in the high strain rate ballistic impact regime. An experimental method has been developed to determine when local material failure has occurred, and whether the failure can be classed as fracture or granular flow. This method is tested on Kolsky bar and ballistic impact experiments. Comparison with numerical simulations is presented.
-
Journal articleEscauriza EM, Olbinado MP, Rutherford ME, et al., 2018,
Ultra-high-speed indirect x-ray imaging system with versatile spatiotemporal sampling capabilities
, APPLIED OPTICS, Vol: 57, Pages: 5004-5010, ISSN: 1559-128X -
Journal articleWhite S, Irwin R, Warwick R, et al., 2018,
Production of photoionized plasmas in the laboratory using X-ray line radiation
, Physical Review E, Vol: 97, ISSN: 1539-3755In this paper we report the experimental implementation of a theoretically proposed technique for creating a photoionized plasma in the laboratory using x-ray line radiation. Using a Sn laser plasma to irradiate an Ar gas target, the photoionization parameter, ξ=4πF/Ne, reached values of order 50ergcms−1, where F is the radiation flux in ergcm−2s−1. The significance of this is that this technique allows us to mimic effective spectral radiation temperatures in excess of 1 keV. We show that our plasma starts to be collisionally dominated before the peak of the x-ray drive. However, the technique is extendable to higher-energy laser systems to create plasmas with parameters relevant to benchmarking codes used to model astrophysical objects.
-
Journal articleMillett JCF, Higgins DL, Chapman DJ, et al., 2018,
The Effects of Prior Cold Work on the Shock Response of Copper
, Journal of Dynamic Behavior of Materials, Vol: 4, Pages: 211-221, ISSN: 2199-7446 -
Journal articleNguyen TN, Sory DR, Rankin SM, et al., 2018,
Platform development for primary blast injury studies
, Trauma (United Kingdom), ISSN: 1460-4086© 2018, The Author(s) 2018. Explosion-related injuries are currently the most commonly occurring wounds in modern conflicts. They are observed in both military and civilian theatres, with complex injury pathophysiologies. Primary blast injuries are the most frequently encountered critical injuries experienced by victims close to the explosion. They are caused by large and rapid pressure changes of the blast waves which produce a wide range of loading patterns resulting in varied injuries. Well-characterised experimental loading devices which can reproduce the real mechanical characteristics of blast loadings on biological specimens in in vivo, ex vivo, and in vitro models are essential in determining the injury mechanisms. This paper discusses the performance and application of platforms, including shock tubes, mechanical testing machines, drop-weight rigs, and split-Hopkinson pressure bar, with regards to the replication of primary blast.
-
Journal articleGurovich V, Virozub A, Rososhek A, et al., 2018,
Quasi-isentropic compression using compressed water flow generated by underwater electrical explosion of a wire array
, Journal of Applied Physics, Vol: 123, ISSN: 0021-8979A major experimental research area in material equation-of-state today involves the use of off-Hugoniot measurements rather than shock experiments that give only Hugoniot data. There is a wide range of applications using quasi-isentropic compression of matter including the direct measurement of the complete isentrope of materials in a single experiment and minimizing the heating of flyer plates for high-velocity shock measurements. We propose a novel approach to generating quasi-isentropic compression of matter. Using analytical modeling and hydrodynamic simulations, we show that a working fluid composed of compressed water, generated by an underwater electrical explosion of a planar wire array, might be used to efficiently drive the quasi-isentropic compression of a copper target to pressures ∼2 × 10 11 Pa without any complex target designs.
-
Journal articleRose SJ, Santos JJ, Bailly-Grandvaux M, et al., 2018,
Laser-driven strong magnetostatic fields with applications to charged beam transport and magnetized high energy-density physics
, Physics of Plasmas, Vol: 25, ISSN: 1070-664XPowerful laser-plasma processes are explored to generate discharge currents of a few 100 kA in coil targets,yielding magnetostatic fields (B-fields) in excess of 0.5 kT. The quasi-static currents are provided from hotelectron ejection from the laser-irradiated surface. According to our model, which describes the evolution ofthe discharge current, the major control parameter is the laser irradianceIlasλ2las. The space-time evolutionof the B-fields is experimentally characterized by high-frequency bandwidth B-dot probes and by proton-deflectometry measurements. The magnetic pulses, of ns-scale, are long enough to magnetize secondary targetsthrough resistive diffusion. We applied it in experiments of laser-generated relativistic electron transportthrough solid dielectric targets, yielding an unprecedented 5-fold enhancement of the energy-density flux at60μm depth, compared to unmagnetized transport conditions. These studies pave the ground for magnetizedhigh-energy density physics investigations, related to laser-generated secondary sources of radiation and/orhigh-energy particles and their transport, to high-gain fusion energy schemes and to laboratory astrophysics.
-
Journal articleHill EG, Perez-Callejo G, Rose SJ, 2018,
ALICE: A non-LTE plasma atomic physics, kinetics and lineshape code
, High Energy Density Physics, Vol: 26, Pages: 56-67, ISSN: 1574-1818All three parts of an atomic physics, atomic kinetics and lineshape code, ALICE, are described. Examples of the code being used to model the emissivity and opacity of plasmas are discussed and interesting features of the code which build on the existing corpus of models are shown throughout.
-
Conference paperDerrick J, Rutherford M, Davison T, et al., 2018,
Interrogating Heterogeneous Compaction of Analogue Materials at the Mesoscale Through Numerical Modeling and Experiments
, 20th Biennial Conference of the APS Topical Group on Shock Compression of Condensed Matter, Publisher: AIP Publishing, ISSN: 1551-7616 -
Journal articleZhang X, Wang G, Luo B, et al., 2018,
Mechanical response of near-equiatomic NiTi alloy at dynamic high pressure and strain rate
, Journal of Alloys and Compounds, Vol: 731, Pages: 569-576, ISSN: 0925-8388Understanding the behavior of near equi-atomic NiTi alloys under high strain rates and high pressures is important for the development of shock mitigating structures, particularly those that protect satellite and space vehicles from the impact of hyper velocity space debris. In this paper, the equation of state and constitutive relationships of NiTi alloy at pressures of 20–50 GPa and strain rates from 104s−1 to 107s−1 were investigated by means of magnetically driven quasi-isentropic compression and by shock compression from the impact of magnetically launched flyer plates. An inflection point at a pressure of 2–3 GPa was found on plots of Lagrangian sound speed versus particle velocity in both quasi-isentropic and shock compression experiments, and it shows the elastic-plastic transition of austenitic NiTi alloy. The effect of the strain rate on the elastic limit of NiTi alloy was clearly seen between strain rates of 104s−1 and 107s−1. We also found that the bulk sound speed calculated from the shock data was lower than that deduced from the ultrasonic measurements. Finally, a rate dependent Johnson–Cook model was modified to describe the dynamic responses of NiTi. With this modified model, hydrodynamic simulations agreed well with our observations.
-
Conference paperMagnus D, Smith LC, Proud WG, 2018,
Multiple Wave Compression of Granular Materials Using the Split-Hopkinson Pressure Bar
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Conference paperMagnus D, Haller A, Jouffroy A, et al., 2018,
Tensile Characterisation of the Aorta across Quasi-static to Blast Loading Strain Rates
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Conference paperProud WG, Ellison K, Yapp SH, et al., 2018,
The Response of Simple Polymer Structures to Dynamic Loading
, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X -
Journal articleRutherford ME, Chapman DJ, Derrick JG, et al., 2017,
Corrigendum: Probing the early stages of shock-induced chondritic meteorite formation at the mesoscale.
, Scientific Reports, Vol: 7, Pages: 1-1, ISSN: 2045-2322This corrects the article DOI: 10.1038/srep45206.
-
Journal articlearora H, nila A, Vitharana K, et al., 2017,
Microstructural consequences of blast lung injury characterised with digital volume correlation
, Frontiers in Materials, Vol: 4, ISSN: 2296-8016This study focuses on microstructural changes that occur within the mammalian lung when subject to blast and how these changes influence strain distributions within the tissue. Shock tube experiments were performed to generate the blast injured specimens (cadaveric Sprague-Dawley rats). Blast overpressures of 100 and 180 kPa were studied. Synchrotron tomography imaging was used to capture volumetric image data of lungs. Specimens were ventilated using a custom-built system to study multiple inflation pressures during each tomography scan. These data enabled the first digital volume correlation (DVC) measurements in lung tissue to be performed. Quantitative analysis was performed to describe the damaged architecture of the lung. No clear changes in the microstructure of the tissue morphology were observed due to controlled low- to moderate-level blast exposure. However, significant focal sites of injury were observed using DVC, which allowed the detection of bias and concentration in the patterns of strain level. Morphological analysis corroborated the findings, illustrating that the focal damage caused by a blast can give rise to diffuse influence across the tissue. It is important to characterize the non-instantly fatal doses of blast, given the transient nature of blast lung in the clinical setting. This research has highlighted the need for better understanding of focal injury and its zone of influence (alveolar interdependency and neighboring tissue burden as a result of focal injury). DVC techniques show great promise as a tool to advance this endeavor, providing a new perspective on lung mechanics after blast.
-
Journal articleRose SJ, Keenan FP, Poppenhaeger K, et al., 2017,
X-ray line coincidence photopumping in a solar flare
, Monthly Notices of the Royal Astronomical Society, Vol: 474, Pages: 3782-3786, ISSN: 0035-8711Line coincidence photopumping is a process where the electrons of an atomic or molecular species are radiatively excited through the absorption of line emission from another species at a coincident wavelength. There are many instances of line coincidence photopumping in astrophysical sources at optical and ultraviolet wavelengths, with the most famous example being Bowen fluorescence (pumping of O III 303.80 Å by He II), but none to our knowledge in X-rays. However, here we report on a scheme where a He-like line of Ne IX at 11.000 Å is photopumped by He-like Na X at 11.003 Å, which predicts significant intensity enhancement in the Ne IX 82.76 Å transition under physical conditions found in solar flare plasmas. A comparison of our theoretical models with published X-ray observations of a solar flare obtained during a rocket flight provides evidence for line enhancement, with the measured degree of enhancement being consistent with that expected from theory, a truly surprising result. Observations of this enhancement during flares on stars other than the Sun would provide a powerful new diagnostic tool for determining the sizes of flare loops in these distant, spatially unresolved, astronomical sources.
-
Journal articleYanuka D, Rososhek A, Bland SN, et al., 2017,
Uniformity of cylindrical imploding underwater shockwaves at very small radii
, Applied Physics Letters, Vol: 111, ISSN: 1077-3118We compare the convergent shockwaves generated from underwater, cylindrical arrays of copperwire exploded by multiple kilo-ampere current pulses on nanosecond and microsecond scales. Inboth cases, the pulsed power devices used for the experiments had the same stored energy ( 500 J)and the wire mass was adjusted to optimize energy transfer to the shockwave. Laser backlit framingimages of the shock front were achieved down to the radius of 30lm. It was found that even in thecase of initial azimuthal non-symmetry, the shock wave self-repairs in the final stages of its motion,leading to a highly uniform implosion. In both these and previous experiments, interference fringeshave been observed in streak and framing images as the shockwave approached the axis. We havebeen able to accurately model the origin of the fringes, which is due to the propagation of the laserbeam diffracting off the uniform converging shock front. The dynamics of the shockwave and itsuniformity at small radii indicate that even with only 500 J stored energies, this technique shouldproduce pressures above 10¹⁰Pa on the axis, with temperatures and densities ideal for warm densematter research.
-
Journal articleOwen GD, Chapman DJ, Whiteman G, et al., 2017,
Spall behaviour of single crystal aluminium at three principal orientations
, Journal of Applied Physics, Vol: 122, ISSN: 0021-8979A series of plate impact experiments have been conducted to study the spall strength of the three principal crystallographic orientations of single crystal aluminium ([100], [110] and, [111]) and ultra-pure polycrystalline aluminium. The samples have been shock loaded at two impact stresses (4 GPa and 10 GPa). Significant differences have been observed in the elastic behaviour, the pullback velocities, and the general shape of the wave profiles, which can be accounted for by considerations of the microscale homogeneity, the dislocation density, and the absence of grain boundaries in the single crystal materials. The data have shown that there is a consistent order of spall strength measured for the four sample materials. The [111] orientation has the largest spall strength and elastic limit, followed closely by [110], [100], and then the polycrystalline material. This order is consistent with both quasi-static data and geometrical consideration of Schmid factors.
-
Journal articleDavison TM, Derrick JG, Collins GS, et al., 2017,
Impact-induced compaction of primitive solar system solids: The need for mesoscale modelling and experiments
, Procedia Engineering, Vol: 204, Pages: 405-412, ISSN: 1877-7058Primitive solar system solids were accreted as highly porous bimodal mixtures of mm-sized chondrules and sub-μm matrix grains. To understand the compaction and lithification of these materials by shock, it is necessary to investigate the process at the mesoscale; i.e., the scale of individual chondrules. Here we document simulations of hypervelocity compaction of primitive materials using the iSALE shock physics model. We compare the numerical methods employed here with shock compaction experiments involving bimodal mixtures of glass beads and silica powder and find good agreement in bulk material response between the experiments and models. The heterogeneous response to shock of bimodal porous mixtures with a composition more appropriate for primitive solids was subsequently investigated: strong temperature dichotomies between the chondrules and matrix were observed (non-porous chondrules remained largely cold, while the porous matrix saw temperature increases of 100’s K). Matrix compaction was heterogeneous, and post-shock porosity was found to be lower on the lee-side of chondrules. The strain in the matrix was shown to be higher near the chondrule rims, in agreement with observations from meteorites. Chondrule flattening in the direction of the shock increases with increasing impact velocity, with flattened chondrules oriented with their semi-minor axis parallel to the shock direction.
-
Journal articleWhiteman G, Owen GD, De'Ath J, et al., 2017,
Spatially resolved measurements of grain size effects on the shock and spall response of quasi-Taylor wave loaded pure copper
, JOURNAL OF APPLIED PHYSICS, Vol: 122, ISSN: 0021-8979
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.