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348 results on '"Markey, K"'

1. Controlling fast electron beam divergence using two laser pulses

Author

Scott, R. H. H., Beaucourt, C., Schlenvoigt, H. -P., Markey, K., Lancaster, K. L., Ridgers, C. P., Brenner, C. M., Pasley, J., Gray, R. J., Musgrave, I. O., Robinson, A. P. L, Li, K., Notley, M. M., Davies, J. R., Baton, S. D., Santos, J. J., Feugeas, J. -L., Nicolaï, Ph., Malka, G., Tikhonchuk, V. T., McKenna, P., Neely, D., Rose, S. J., and Norreys, P. A.

Subjects
Physics - Plasma Physics
Abstract

This paper describes the first experimental demonstration of the guiding of a relativistic electron beam in a solid target using two co-linear, relativistically intense, picosecond laser pulses. The first pulse creates a magnetic field which guides the higher current fast electron beam generated by the second pulse. The effects of intensity ratio, delay, total energy and intrinsic pre-pulse are examined. Thermal and K{\alpha} imaging showed reduced emission size, increased peak emission and increased total emission at delays of 4 - 6 ps, an intensity ratio of 10 : 1 (second:first) and a total energy of 186 J. In comparison to a single, high contrast shot, the inferred fast electron divergence is reduced by 2.7 times, while the fast electron current density is increased by a factor of 1.8. The enhancements are reproduced with modelling and are shown to be due to the self-generation of magnetic fields. Such a scheme could be of considerable benefit to fast ignition inertial fusion.

Published
2010
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2. Micron-scale Fast Electron Filamentation and Recirculation determined from Rear Side Optical Emission in High Intensity Laser-Solid Interactions

Author

Bellei, C., Nagel, S. R., Kar, S., Henig, A., Kneip, S., Palmer, C., Sävert, A., Willingale, L., Carroll, D., Dromey, B., Green, J. S., Markey, K., Simpson, P., Clarke, R. J., Lowe, H., Neely, D., Spindloe, C., Tolley, M., Kaluza, M., Mangles, S. P. D., McKenna, P., Norreys, P. A., Schreiber, J., Zepf, M., Davies, J. R., Krushelnick, K., and Najmudin, Z.

Subjects
Physics - Plasma Physics
Abstract

The transport of relativistic electrons generated in the interaction of petawatt class lasers with solid targets has been studied through measurements of the optical emission from their rear surface. The high degree of polarization of the emission indicates that it is predominantly optical transition radiation. A halo that surrounds the main region of emission is also polarized, and is attributed to the effect of electron recirculation. The variation of the amplitude of the transition radiation with respect to observation angle provides evidence for the presence of {$\mu$m-size} filaments., Comment: 12 pages, 7 figures

Published
2010
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3. Dynamic Control of Laser Produced Proton Beams

Author

Kar, S., Markey, K., Simpson, P. T., Dromey, B., Borghesi, M., Zepf, M., Bellei, C., Nagel, S. R., Kneip, S., Willingale, L., Najmudin, Z., Krushelnick, K., Green, J. S., Norreys, P., Clarke, R. J., Neely, D., Carroll, D. C., McKenna, P., and Clark, E. L.

Subjects
Physics - Plasma Physics, Physics - Accelerator Physics
Abstract

The emission characteristics of intense laser driven protons are controlled using ultra-strong (of the order of 10^9 V/m) electrostatic fields varying on a few ps timescale. The field structures are achieved by exploiting the high potential of the target (reaching multi-MV during the laser interaction). Suitably shaped targets result in a reduction in the proton beam divergence, and hence an increase in proton flux while preserving the high beam quality. The peak focusing power and its temporal variation are shown to depend on the target characteristics, allowing for the collimation of the inherently highly divergent beam and the design of achromatic electrostatic lenses., Comment: 9 Pages, 5 figures

Published
2007
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7. Probing bulk electron temperature via x-ray emission in a solid density plasma

Author

Makur, K, primary, Ramakrishna, B, additional, Krishnamurthy, S, additional, Kakolee, K F, additional, Kar, S, additional, Cerchez, M, additional, Prasad, R, additional, Markey, K, additional, Quinn, M N, additional, Yuan, X H, additional, Green, J S, additional, Scott, R H H, additional, McKenna, P, additional, Osterholz, J, additional, Willi, O, additional, Norreys, P A, additional, Borghesi, M, additional, and Zepf, M, additional

Published
2023
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10. 11βHSD1 Inhibition with AZD4017 Improves Lipid Profiles and Lean Muscle Mass in Idiopathic Intracranial Hypertension

Author

Hardy, RS, Botfield, H, Markey, K, Mitchell, JL, Alimajstorovic, Z, Westgate, CSJ, Sagmeister, M, Fairclough, RJ, Ottridge, RS, Yiangou, A, Storbeck, K-HH, Taylor, AE, Gilligan, LC, Arlt, W, Stewart, PM, Tomlinson, JW, Mollan, SP, Lavery, GG, and Sinclair, AJ

Abstract

Background The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) determines prereceptor metabolism and activation of glucocorticoids within peripheral tissues. Its dysregulation has been implicated in a wide array of metabolic diseases, leading to the development of selective 11β-HSD1 inhibitors. We examined the impact of the reversible competitive 11β-HSD1 inhibitor, AZD4017, on the metabolic profile in an overweight female cohort with idiopathic intracranial hypertension (IIH). Methods We conducted a UK multicenter phase II randomized, double-blind, placebo-controlled trial of 12-week treatment with AZD4017. Serum markers of glucose homeostasis, lipid metabolism, renal and hepatic function, inflammation and androgen profiles were determined and examined in relation to changes in fat and lean mass by dual-energy X-ray absorptiometry. Results Patients receiving AZD4017 showed significant improvements in lipid profiles (decreased cholesterol, increased high-density lipoprotein [HDL] and cholesterol/HDL ratio), markers of hepatic function (decreased alkaline phosphatase and gamma-glutamyl transferase), and increased lean muscle mass (1.8%, P < .001). No changes in body mass index, fat mass, and markers of glucose metabolism or inflammation were observed. Patients receiving AZD4017 demonstrated increased levels of circulating androgens, positively correlated with changes in total lean muscle mass. Conclusions These beneficial metabolic changes represent a reduction in risk factors associated with raised intracranial pressure and represent further beneficial therapeutic outcomes of 11β-HSD1 inhibition by AZD4017 in this overweight IIH cohort. In particular, beneficial changes in lean muscle mass associated with AZD4017 may reflect new applications for this nature of inhibitor in the management of conditions such as sarcopenia.

Published
2021

20. WHO Expert Committee on Biological Standardization Introduction

Author

Cichutek, K., Darko, M., Epstein, J., Hindawi, S., Jivapaisarnpong, T., Klein, H., Morris, C., Reddy, V.R., Strengers, P., Sohn, Y., Teo, D., Wang, J., Griffiths, E., Gruber, M., Hamel, H., Lacana, E., Reinhardt, J., Sun, Y., Udell, M., Besselaar, A.M.H.P. van den, Waddell, A.L., Agbanyo, F., Almond, N., Bowyer, P., Boyle, J., Burns, C., Cooper, G., Cowper, B., Elmgren, L., Engelhardt, O., Fox, B., Govind, S., Gray, E., Hamaguchi, I., Ilonze, C.C., Kato, A., Kaslow, D., Kress, J., Lery, F.X., Markey, K., Metcalfe, C., Meyer, H., Minor, P., Nam, K., Ochiai, M., Oh, H., Padley, D., Page, M., Prior, S., Rijpkema, S., Ryu, S.R., Scharer, C., Scheiblauer, H., Schneider, C., Smith, G., Southern, J., Stahl, D., Stickings, P., Studholme, L., Thelwell, C., Thorpe, R., Vasheghani, A., Verdun, N., Williams, D., Wilkinson, D., Xu, M., Yoo, S.H., Zhang, C., Yueming, R., Dellepiane, N., Paradkar, V., Yufeng, Y., Buchheit, K.H., Charton, E., Wierer, M., Neels, P., Schreitmueller, T., Ooij, M. van, Watson, K., Schwarzenberger, I., Misztela, D., Atouf, F., Akanmori, B.D., Hill, S., Cooke, E., Knezevic, I., Nubling, M., Jenner, S., Friede, M., Kang, H.N., Khadem, A., Kopp, S., Lei, D., Meurant, R., Mubangizi, D., Rosskopf, U., Shin, I., Ward, M., Zhou, T., Cree, I.A., WHO Expert Comm Biol Standardizat, Chinese Pharmacopoeia Commission, Dev Countries Vaccine Manufacturer, European Directorate Quality Med H, Int Alliance Biol Standardization, Int Federation Pharmaceutical Manu, Int Generic Biosimilar Med Assoc, Plasma Prot Therapeutics Assoc, and US Pharmacopeial Convention

Published
2018

21. Lactose drives Enterococcus expansion to promote graft-versus-host disease

Author

Stein-Thoeringer, C. K., Nichols, K. B., Lazrak, A., Docampo, M. D., Slingerland, A. E., Slingerland, J. B., Clurman, A. G., Armijo, G., Gomes, A. L. C., Shono, Y., Staffas, A., da Silva, M. Burgos, Devlin, S. M., Markey, K. A., Bajic, D., Pinedo, R., Tsakmaklis, A., Littmann, E. R., Pastore, A., Taur, Y., Monette, S., Arcila, M. E., Pickard, A. J., Maloy, M., Wright, R. J., Amoretti, L. A., Fontana, E., Pham, D., Jamal, M. A., Weber, D., Sung, A. D., Hashimoto, D., Scheid, C., Xavier, J. B., Messina, J. A., Romero, K., Lew, M., Bush, A., Bohannon, L., Hayasaka, K., Hasegawa, Y., Vehreschild, M. J. G. T., Cross, J. R., Ponce, D. M., Perales, M. A., Giralt, S. A., Jenq, R. R., Teshima, T., Holler, E., Chao, N. J., Pamer, E. G., Peled, J. U., van den Brink, M. R. M., Stein-Thoeringer, C. K., Nichols, K. B., Lazrak, A., Docampo, M. D., Slingerland, A. E., Slingerland, J. B., Clurman, A. G., Armijo, G., Gomes, A. L. C., Shono, Y., Staffas, A., da Silva, M. Burgos, Devlin, S. M., Markey, K. A., Bajic, D., Pinedo, R., Tsakmaklis, A., Littmann, E. R., Pastore, A., Taur, Y., Monette, S., Arcila, M. E., Pickard, A. J., Maloy, M., Wright, R. J., Amoretti, L. A., Fontana, E., Pham, D., Jamal, M. A., Weber, D., Sung, A. D., Hashimoto, D., Scheid, C., Xavier, J. B., Messina, J. A., Romero, K., Lew, M., Bush, A., Bohannon, L., Hayasaka, K., Hasegawa, Y., Vehreschild, M. J. G. T., Cross, J. R., Ponce, D. M., Perales, M. A., Giralt, S. A., Jenq, R. R., Teshima, T., Holler, E., Chao, N. J., Pamer, E. G., Peled, J. U., and van den Brink, M. R. M.

Abstract

Disruption of intestinal microbial communities appears to underlie many human illnesses, but the mechanisms that promote this dysbiosis and its adverse consequences are poorly understood. In patients who received allogeneic hematopoietic cell transplantation (allo-HCT), we describe a high incidence of enterococcal expansion, which was associated with graft-versus-host disease (GVHD) and mortality. We found that Enterococcus also expands in the mouse gastrointestinal tract after allo-HCT and exacerbates disease severity in gnotobiotic models. Enterococcus growth is dependent on the disaccharide lactose, and dietary lactose depletion attenuates Enterococcus outgrowth and reduces the severity of GVHD in mice. Allo-HCT patients carrying lactose-nonabsorber genotypes showed compromised clearance of postantibiotic Enterococcus domination. We report lactose as a common nutrient that drives expansion of a commensal bacterium that exacerbates an intestinal and systemic inflammatory disease.

Published
2019

23. Lactose drives Enterococcus expansion to promote graft-versus-host disease

Author

Stein-Thoeringer, C. K., primary, Nichols, K. B., additional, Lazrak, A., additional, Docampo, M. D., additional, Slingerland, A. E., additional, Slingerland, J. B., additional, Clurman, A. G., additional, Armijo, G., additional, Gomes, A. L. C., additional, Shono, Y., additional, Staffas, A., additional, Burgos da Silva, M., additional, Devlin, S. M., additional, Markey, K. A., additional, Bajic, D., additional, Pinedo, R., additional, Tsakmaklis, A., additional, Littmann, E. R., additional, Pastore, A., additional, Taur, Y., additional, Monette, S., additional, Arcila, M. E., additional, Pickard, A. J., additional, Maloy, M., additional, Wright, R. J., additional, Amoretti, L. A., additional, Fontana, E., additional, Pham, D., additional, Jamal, M. A., additional, Weber, D., additional, Sung, A. D., additional, Hashimoto, D., additional, Scheid, C., additional, Xavier, J. B., additional, Messina, J. A., additional, Romero, K., additional, Lew, M., additional, Bush, A., additional, Bohannon, L., additional, Hayasaka, K., additional, Hasegawa, Y., additional, Vehreschild, M. J. G. T., additional, Cross, J. R., additional, Ponce, D. M., additional, Perales, M. A., additional, Giralt, S. A., additional, Jenq, R. R., additional, Teshima, T., additional, Holler, E., additional, Chao, N. J., additional, Pamer, E. G., additional, Peled, J. U., additional, and van den Brink, M. R. M., additional

Published
2019
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25. Micron-scale fast electron filaments and recirculation determined from rear-side optical emission in high-intensity laser-solid interactions

Author

Bellei, C, Nagel, SR, Kar, S, Henig, A, Kneip, S, Palmer, C, Sävert, A, Willingale, L, Carroll, D, Dromey, B, Green, J, Markey, K, Simpson, P, Clarke, R, Lowe, H, Neely, D, Spindloe, C, Tolley, M, Kaluza, M, Mangles, S, McKenna, P, Norreys, P, Schreiber, J, Zepf, M, and Davies, JR

Abstract

The transport of relativistic electrons generated in the interaction of petawatt class lasers with solid targets has been studied through measurements of the second harmonic optical emission from their rear surface. The high degree of polarization of the emission indicates that it is predominantly optical transition radiation (TR). A halo that surrounds the main region of emission is also polarized and is attributed to the effect of electron recirculation. The variation of the polarization state and intensity of radiation with the angle of observation indicates that the emission of TR is highly directional and provides evidence for the presence of μm-size filaments. A brief discussion on the possible causes of such a fine electron beam structure is given. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Published
2016
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26. Water adsorption behaviour of CAU-10-H

Author

Fröhlich, D., Pantatosaki, E., Kolokathis, P.D., Markey, K., Reinsch, H., Baumgartner, M., Veen, M.A. van der, Vos, D.E. de, Stock, N., Papadopoulos, G.K., Henninger, S.K., Janiak, C., and Publica

Subjects
Thermische Anlagen und Gebäudetechnik, adsorption chiller, adsorption heat pump, adsorption, adsorptive coating, Wärme- und Kälteversorgung, Gebäudeenergietechnik, Materialien und Komponenten für Wärmetransformation, MOF
Abstract

Aluminium isophthalate CAU-10-H [Al(OH)(benzene-1,3-dicarboxylate)]·nH2O exhibits water adsorption characteristics which make it a promising adsorbent for application in heat-exchange processes. Herein we prepared a stable coating of this MOF and evaluated its long-term stability under closed-cycle conditions for 10000 water adsorption and desorption cycles, which are typical lifetimes for adsorption heat storage (AHS) applications. No degradation of the adsorption capacity could be observed which makes CAU-10-H the most stable MOF under these humid cycling conditions reported until now. Moreover, thermophysical properties like thermal conductivity and heat of adsorption were directly measured. In order to identify the structural features associated with the adsorption behaviour, the structural differences between the dry and the water loaded CAU-10-H were studied by Rietveld refinements and second harmonic generation (SHG) microscopy.

Published
2016

28. Evaluation of a cognitive skills programme for male prisoners – exploring treatment effectiveness

Author

Ireland, Jane Louise, Bates-Gaston, J, Markey, K, Greenwood, Leah Charlotte, Ireland, Carol Ann, Ireland, Jane Louise, Bates-Gaston, J, Markey, K, Greenwood, Leah Charlotte, and Ireland, Carol Ann

Abstract

Aim: The current study provides an evaluation of a cognitive skills programme (Enhanced Thinking Skills) with adult prisoners. Method: A pre and post treatment-only design with 171 male prisoners, using self-report psychometric measures. Results: Significant differences were found in the direction expected. Clinical recovery using stringent methods was not indicated, although improvement/partial response was across a number of domains. Originality: This study represents the first prison study to distinguish between levels of positive change. It questions previous interpretations of treatment outcome. Implications for practice: Expectations for treatment outcome for short term interventions should be more realistic; Cognitive skills programmes may be best considered as precursors to longer term therapies; Treatment outcome should focus on improvement and not recovery.

Published
2016

29. Water adsorption behaviour of CAU-10-H: a thorough investigation of its structure–property relationships

Author

Fröhlich, D. (author), Pantatosaki, E. (author), Kolokathis, P.D. (author), Markey, K (author), Reinsch, H. (author), Baumgartner, M. (author), van der Veen, M.A. (author), De Vos, D.E. (author), Stock, N (author), Papadopoulos, G.K. (author), Henninger, S.K. (author), Janiak, C. (author), Fröhlich, D. (author), Pantatosaki, E. (author), Kolokathis, P.D. (author), Markey, K (author), Reinsch, H. (author), Baumgartner, M. (author), van der Veen, M.A. (author), De Vos, D.E. (author), Stock, N (author), Papadopoulos, G.K. (author), Henninger, S.K. (author), and Janiak, C. (author)

Abstract

Aluminium isophthalate CAU-10-H [Al(OH)(benzene-1,3-dicarboxylate)]·nH2O exhibits water adsorption characteristics which make it a promising adsorbent for application in heat-exchange processes. Herein we prepared a stable coating of this MOF and evaluated its long-term stability under closed-cycle conditions for 10 000 water adsorption and desorption cycles, which are typical lifetimes for adsorption heat storage (AHS) applications. No degradation of the adsorption capacity could be observed which makes CAU-10-H the most stable MOF under these humid cycling conditions reported until now. Moreover, thermophysical properties like thermal conductivity and heat of adsorption were directly measured. In order to identify the structural features associated with the adsorption behaviour, the structural differences between the dry and the water loaded CAU-10-H were studied by Rietveld refinements and second harmonic generation (SHG) microscopy. The observed transition of space group symmetry from I41 to I41/amd between the humid and dry forms is induced by the adsorption/desorption of water into/out of the MOF channels. This originates from a torsional motion around the C–C bond between the carboxylate groups and the aromatic ring in half of the linker molecules. These observations are in excellent agreement with molecular dynamics simulations which confirm the energetic benefit of this transition., ChemE/Catalysis Engineering

Published
2016
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30. Second harmonic generation microscopy reveals hidden polar organization in fluoride doped MIL-53(Fe)

Author

Markey, K. (author), Putzeys, T. (author), Horcajada, P. (author), Devic, T. (author), Guillou, N. (author), Wübbenhorst, M. (author), Van Cleuvenbergen, S. (author), Verbiest, T. (author), De Vos, D.E. (author), Van der Veen, M.A. (author), Markey, K. (author), Putzeys, T. (author), Horcajada, P. (author), Devic, T. (author), Guillou, N. (author), Wübbenhorst, M. (author), Van Cleuvenbergen, S. (author), Verbiest, T. (author), De Vos, D.E. (author), and Van der Veen, M.A. (author)

Abstract

Polar metal–organic frameworks have potential applications as functional non-linear optical, piezoelectric, pyroelectric and ferroelectric materials. Using second harmonic generation microscopy we found that fluoride doping of the microporous iron(III) terephthalate MOF MIL-53(Fe) induces a polar organization in its structure, which was not previously detected with XRD. The polar order is only observed when both fluoride and guest molecules are present, and may be related to a complex interplay between the adsorbates and the framework, leading to a modification of the positioning of fluoride in the inorganic Fe-chains. Combined polarized second harmonic generation microscopy and scanning pyroelectric microscopy show that the polar axis is unidirectional and of the same sense over the whole crystal, extending up to 100 micrometers. This finding shows how MOF materials can be endowed with useful properties by doping MOFs with fluoride., Chemical Engineering, Applied Sciences

Published
2016
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33. Optimized retinal nerve fiber layer segmentation based on optical reflectivity and birefringence for polarization-sensitive optical coherence tomography

Author

Biwei Yin, Markey K. Markey, Bingqing Wang, Thomas E. Milner, H. Grady Rylander, Amit S. Paranjape, and Shuang Liu

Subjects
Materials science, Birefringence, genetic structures, medicine.diagnostic_test, business.industry, Nerve fiber layer, Speckle noise, Image processing, Retinal ganglion, eye diseases, Speckle pattern, Optics, medicine.anatomical_structure, Optical coherence tomography, medicine, sense organs, business, Refractive index
Abstract

Segmentation of the retinal nerve fiber layer (RNFL) from swept source polarization-sensitive optical coherence tomography (SS-PSOCT) images is required to determine RNFL thickness and calculate birefringence. Traditional RNFL segmentation methods based on image processing and boundary detection algorithms utilize only optical reflectivity contrast information, which is strongly affected by speckle noise. We present a novel approach to segment the retinal nerve fiber layer (RNFL) using SS-PSOCT images including both optical reflectivity and phase retardation information. The RNFL anterior boundary is detected based on optical reflectivity change due to refractive index difference between the vitreous and inner limiting membrane. The posterior boundary of the RNFL is a transition zone composed of birefringent axons extending from retinal ganglion cells and may be detected by a change in birefringence. A posterior boundary detection method is presented that segments the RNFL by minimizing the uncertainty of RNFL birefringence determined by a Levenberg-Marquardt nonlinear fitting algorithm. Clinical results from a healthy volunteer show that the proposed segmentation method estimates RNFL birefringence and phase retardation with lower uncertainty and higher continuity than traditional intensity-based approaches.

Published
2011
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35. Effect of laser intensity on fast-electron-beam divergence in solid-density plasmas (Physical Review Letters (2008) 100 (015003))

Author

Green, JS, Ovchinnikov, VM, Evans, RG, Akli, KU, Azechi, H, Beg, FN, Bellei, C, Freeman, RR, Habara, H, Heathcote, R, Key, MH, King, JA, Lancaster, KL, Lopes, NC, Ma, T, MacKinnon, AJ, Markey, K, McPhee, A, Najmudin, Z, Nilson, P, Onofrei, R, Stephens, R, Takeda, K, Tanaka, KA, Theobald, W, Tanimoto, T, Waugh, J, Van Woerkom, L, Woolsey, NC, Zepf, M, Davies, JR, and Norreys, PA

Published
2008

36. Nationwide Census of Institutional Repositories: Preliminary Findings

Author

Markey, K., Beth St. Jean, Soo, Y. R., Yakel, E., Kim, J., Kim, Y. -M, and Institute of Museum and Library Services (IMLS) through a National Leadership Grant (LG 06-05-0126).

Subjects
Institutional Repositories, Perceived benefits, Staffing, Recruitment of Contributions, Costs
Abstract

The MIRACLE (Making Institutional Repositories A Collaborative Learning Environment) Project is a multi-phased research project that is investigating the development of institutional repositories (IRs) in U. S. colleges and universities to identify models and best practices in the administration, technical infrastructure, access to, and preservation of repository collections. This paper features preliminary findings from the project’s first phase, a nationwide census that will reveal the extent of college and university involvement with IRs in the United States. Preliminary findings address the types of investigative activities that institutions are conducting prior to making the decision to implement an IR, perceived benefits of IRs, staffing for IRs, methods of recruiting digital content, characteristics of operational IRs including their costs, and participating institutions’ next steps on the road to implementing an IR.

Published
2007

39. CSF-1-Dependant M2 Macrophages Mediate Chronic Graft-Versus-Host Disease.

Author

Alexander, K., primary, Flynn, R., additional, Lineburg, K., additional, Kuns, R., additional, Janela, B., additional, Teal, B., additional, Olver, S., additional, Lor, M., additional, Raffelt, N., additional, Koyama, M., additional, Leveque, L., additional, Le Texier, L., additional, Melino, M., additional, Markey, K., additional, Varelias, A., additional, Ginhoux, F., additional, Engwerda, C., additional, Clouston, A., additional, Blazer, B., additional, Hill, G., additional, and MacDonald, K., additional

Published
2014
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40. High energy conversion efficiency in laser-proton acceleration by controlling laser-energy deposition onto thin foil targets

Author

Brenner, C. M., primary, Robinson, A. P. L., additional, Markey, K., additional, Scott, R. H. H., additional, Gray, R. J., additional, Rosinski, M., additional, Deppert, O., additional, Badziak, J., additional, Batani, D., additional, Davies, J. R., additional, Hassan, S. M., additional, Lancaster, K. L., additional, Li, K., additional, Musgrave, I. O., additional, Norreys, P. A., additional, Pasley, J., additional, Roth, M., additional, Schlenvoigt, H.-P., additional, Spindloe, C., additional, Tatarakis, M., additional, Winstone, T., additional, Wolowski, J., additional, Wyatt, D., additional, McKenna, P., additional, and Neely, D., additional

Published
2014
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41. Enhancement of ion generation in femtosecond ultraintense laser-foil interactions by defocusing

Author

Xu, M. H., Li, Y. T., Carroll, D. C., Foster, P. S., Hawkes, S., Kar, S., Liu, F., Markey, K., McKenna, P., Streeter, M. J. V., Spindloe, C., Sheng, Z. M., Wahlström, Claes-Göran, Zepf, M., Zheng, J., Zhang, J., Neely, D., Xu, M. H., Li, Y. T., Carroll, D. C., Foster, P. S., Hawkes, S., Kar, S., Liu, F., Markey, K., McKenna, P., Streeter, M. J. V., Spindloe, C., Sheng, Z. M., Wahlström, Claes-Göran, Zepf, M., Zheng, J., Zhang, J., and Neely, D.

Abstract

A simple method to enhance ion generation with femtosecond ultraintense lasers is demonstrated experimentally by defocusing laser beams on target surface. When the laser is optimally defocused, we find that the population of medium and low energy protons from ultra-thin foils is increased significantly while the proton cutoff energy is almost unchanged. In this way, the total proton yield can be enhanced by more than 1 order, even though the peak laser intensity drops. The depression of the amplified spontaneous emission (ASE) effect and the population increase of moderate-energy electrons are believed to be the main reasons for the effective enhancement. (C) 2012 American Institute of Physics. [doi:10.1063/1.3688027]

Published
2012

42. ELI - Extreme Light Infrastructure Science and Technology with Ultra-Intense Lasers. Whitebook

Author

Aleonard, M. M., Altarelli, M., Antici, P., Apolonskiy, A., Audebert, P., Bartnik, A., Barty, C. P. J., Bernstein, A., Biegert, J., Böni, P., Booth, N., Borghesi, M., Bote, D., Bulanov, S. V., Butkus, R., Cardoso, L., Chambaret, J. P., Charambilidis, D., Cheriaux, G., Clarke, R., Collier, J., Cramer, L., Czitrovsky, A., D’Humières, E., Di Piazza, A., Dietz, B., Ditmire, T., Dombi, P., Dorobantu, A., Dyer, G., Ernstorfer, R., Ertel, K., Esarey, E., Esirkepov, T. Z., Esposito, A., Fajardo, M., Fedotov, A., Fenic, C., Fernandez, F., Ferrari, A., Földes, I. D., Frederickson, C., Fuchs, J., Fülöp, J. A., Fülöp, Z., Galimberti, M., Gaul, E., Gies, H., Giulietti, A., Giulietti, D., Gizzi, L., Gliksohn, F., Goulielmakis, E., Grigsby, W., Gross, M., Grüner, F., Habs, D., Hajdu, J., Hajima, R., Harman, Z., Hatsagortsian, K. Z., Hebling, J., Kalashnikov, M. P., Kalpouzos, C., Karsch, S., Keitel, C. H., Kiefer, D., Kienberger, R., Kling, M., Kneip, S., Korn, G., Köster, U., Kovács, M., Kozlova, M., Kraft, G., Kraft, S., Krausz, F., Lancaster, K. L., Le Blanc, C., Le Garrec, B., Leemans, W., Lenner, M., Limpouch, J., Lippenyi, T., Lopes, N. C., Lopez-Martens, R., Ma, W., Major, Z., Margarone, D., Markey, K., Marklund, M., Marti, M., Martinez, M., Mason, P., Mathieu, F., Metzger, T., Mocek, T., Molls, M., Mourou, G., Moustaizis, S. D., Müller, C., Murphy, C. D., Musgrave, I., Narozhny, N. B., Naumova, N., Neely, D., Negoita, F., Nickles, P. V., Nisoli, M., Oliva, E., Osvay, K., Paillard, J. L., Pepler, D., Pegoraro, F., Pervak, V., Petrillo, V., Pfeiffer, F., Pietralla, N., Piskarksas, A., Ploumistakis, I., Poleto, L., Priebe, G., Rodriguez Tajes, C., Rohlena, K., Roth, M., Ruhl, H., Ruiz, C., Rus, B., Ruth, R., Růžička, V., Sandner, W., Sansone, G., Savran, D., Schreiber, J., Schützhold, R., Serafini, L., Silva, L., Silvestri, S., Sonnabend, K., Stehle, C., Symes, D. R., Szabo, G., Tajima, T., Tempea, G., Thirolf, P. G., Thomas, A. G. R., Tikhonchuk, V., Tsakiris, G. D., Tsohantjis, I., Tzallas, P., Urruti, E., Ursescu, D., Varjú, K., Veisz, L., Vrakking, M., Weidenmüller, H. A., White, W., Wilkens, J. J., Will, I., Winstone, T., Wittman, T., Woolsey, N., Wormser, G., Yan, X. Q., Zamfir, N. V., Zepf, M., Aleonard, M. M., Altarelli, M., Antici, P., Apolonskiy, A., Audebert, P., Bartnik, A., Barty, C. P. J., Bernstein, A., Biegert, J., Böni, P., Booth, N., Borghesi, M., Bote, D., Bulanov, S. V., Butkus, R., Cardoso, L., Chambaret, J. P., Charambilidis, D., Cheriaux, G., Clarke, R., Collier, J., Cramer, L., Czitrovsky, A., D’Humières, E., Di Piazza, A., Dietz, B., Ditmire, T., Dombi, P., Dorobantu, A., Dyer, G., Ernstorfer, R., Ertel, K., Esarey, E., Esirkepov, T. Z., Esposito, A., Fajardo, M., Fedotov, A., Fenic, C., Fernandez, F., Ferrari, A., Földes, I. D., Frederickson, C., Fuchs, J., Fülöp, J. A., Fülöp, Z., Galimberti, M., Gaul, E., Gies, H., Giulietti, A., Giulietti, D., Gizzi, L., Gliksohn, F., Goulielmakis, E., Grigsby, W., Gross, M., Grüner, F., Habs, D., Hajdu, J., Hajima, R., Harman, Z., Hatsagortsian, K. Z., Hebling, J., Kalashnikov, M. P., Kalpouzos, C., Karsch, S., Keitel, C. H., Kiefer, D., Kienberger, R., Kling, M., Kneip, S., Korn, G., Köster, U., Kovács, M., Kozlova, M., Kraft, G., Kraft, S., Krausz, F., Lancaster, K. L., Le Blanc, C., Le Garrec, B., Leemans, W., Lenner, M., Limpouch, J., Lippenyi, T., Lopes, N. C., Lopez-Martens, R., Ma, W., Major, Z., Margarone, D., Markey, K., Marklund, M., Marti, M., Martinez, M., Mason, P., Mathieu, F., Metzger, T., Mocek, T., Molls, M., Mourou, G., Moustaizis, S. D., Müller, C., Murphy, C. D., Musgrave, I., Narozhny, N. B., Naumova, N., Neely, D., Negoita, F., Nickles, P. V., Nisoli, M., Oliva, E., Osvay, K., Paillard, J. L., Pepler, D., Pegoraro, F., Pervak, V., Petrillo, V., Pfeiffer, F., Pietralla, N., Piskarksas, A., Ploumistakis, I., Poleto, L., Priebe, G., Rodriguez Tajes, C., Rohlena, K., Roth, M., Ruhl, H., Ruiz, C., Rus, B., Ruth, R., Růžička, V., Sandner, W., Sansone, G., Savran, D., Schreiber, J., Schützhold, R., Serafini, L., Silva, L., Silvestri, S., Sonnabend, K., Stehle, C., Symes, D. R., Szabo, G., Tajima, T., Tempea, G., Thirolf, P. G., Thomas, A. G. R., Tikhonchuk, V., Tsakiris, G. D., Tsohantjis, I., Tzallas, P., Urruti, E., Ursescu, D., Varjú, K., Veisz, L., Vrakking, M., Weidenmüller, H. A., White, W., Wilkens, J. J., Will, I., Winstone, T., Wittman, T., Woolsey, N., Wormser, G., Yan, X. Q., Zamfir, N. V., and Zepf, M.

Abstract

The ELI Whitebook contains the description of the science, the technology basis and the implementation of the new international scientific infrastructure Extreme Light Infrastructure (ELI)

Published
2011

43. Third harmonic order imaging as a focal spot diagnostic for high intensity laser-solid interactions

Author

Dromey, B., Bellei, C., Carroll, D. C., Clarke, R. J., Green, J. S., Kar, S., Kneip, S., Markey, K., Nagel, S. R., Willingale, L., McKenna, P., Neely, D., Najmudin, Z., Krushelnick, K., Norreys, P. A., Zepf, M., Dromey, B., Bellei, C., Carroll, D. C., Clarke, R. J., Green, J. S., Kar, S., Kneip, S., Markey, K., Nagel, S. R., Willingale, L., McKenna, P., Neely, D., Najmudin, Z., Krushelnick, K., Norreys, P. A., and Zepf, M.

Abstract

As the state of the art for high power laser systems increases from terawatt to petawatt level and beyond, a crucial parameter for routinely monitoring high intensity performance is laser spot size on a solid target during an intense interaction in the tight focus regime (<10 mu m). Here we present a novel, simple technique for characterizing the spatial profile of such a laser focal spot by imaging the interaction region in third harmonic order (3 omega(laser)). Nearly linear intensity dependence of 3 omega(laser) generation for interactions > 10(19) Wcm(-2) is demonstrated experimentally and shown to provide the basis for an effective focus diagnostic. Importantly, this technique is also shown to allow in-situ diagnosis of focal spot quality achieved after reflection from a double plasma mirror setup for very intense high contrast interactions (> 10(20) Wcm(-2)) an important application for the field of high laser contrast interaction science.

Published
2009

44. Dynamic control of laser-produced proton beams

Author

Kar, S., Markey, K., Simpson, P. T., Bellei, C., Green, J. S., Nagel, S. R., Kneip, S., Carroll, D. C., Dromey, B., Willingale, L., Clark, E. L., McKenna, P., Najmudin, Z., Krushelnick, K., Norreys, P., Clarke, R. J., Neely, D., Borghesi, M., Zepf, M., Kar, S., Markey, K., Simpson, P. T., Bellei, C., Green, J. S., Nagel, S. R., Kneip, S., Carroll, D. C., Dromey, B., Willingale, L., Clark, E. L., McKenna, P., Najmudin, Z., Krushelnick, K., Norreys, P., Clarke, R. J., Neely, D., Borghesi, M., and Zepf, M.

Abstract

The emission characteristics of intense laser driven protons are controlled using ultrastrong (of the order of 10(9) V/m) electrostatic fields varying on a few ps time scale. The field structures are achieved by exploiting the high potential of the target (reaching multi-MV during the laser interaction). Suitably shaped targets result in a reduction in the proton beam divergence, and hence an increase in proton flux while preserving the high beam quality. The peak focusing power and its temporal variation are shown to depend on the target characteristics, allowing for the collimation of the inherently highly divergent beam and the design of achromatic electrostatic lenses.

Published
2008

45. Laser driven MeV proton beam focussing by auto-charged electrostatic lens configuration

Author

Kar, S., Markey, K., Simpson, P. T., Bellei, C., Green, J. S., Nagel, S. R., Kneip, S., Carroll, D. C., Dromey, B., Willingale, L., Clark, E. L., McKenna, P., Najmudin, Z., Krushelnick, K., Norreys, P., Clarke, R. J., Neely, D., Borghesi, M., Schiavi, A., Zepf, M., Kar, S., Markey, K., Simpson, P. T., Bellei, C., Green, J. S., Nagel, S. R., Kneip, S., Carroll, D. C., Dromey, B., Willingale, L., Clark, E. L., McKenna, P., Najmudin, Z., Krushelnick, K., Norreys, P., Clarke, R. J., Neely, D., Borghesi, M., Schiavi, A., and Zepf, M.

Abstract

Significant reduction of inherent large divergence of the laser driven MeV proton beams is achieved by strong (of the order of 10(9) V/m) electrostatic focussing field generated in the confined region of a suitably shaped structure attached to the proton generating foil. The scheme exploits the positively charging of the target following an intense laser interaction. Reduction in the proton beam divergence, and commensurate increase in proton flux is observed while preserving the beam laminarity. The underlying mechanism has been established by the help of particle tracing simulations. Dynamic focussing power of the lens, mainly due to the target discharging, can also be exploited in order to bring up the desired chromaticity of the lens for the proton beams of broad energy range.

Published
2008

46. Nuclear activation as a high dynamic range diagnostic of laser-plasma interactions

Author

Clarke, R. J., Simpson, P. T., Kar, S., Green, J. S., Bellei, C., Carroll, D. C., Dromey, B., Kneip, S., Markey, K., McKenna, P., Murphy, W., Nagel, S., Willingale, L., Zepf, M., Clarke, R. J., Simpson, P. T., Kar, S., Green, J. S., Bellei, C., Carroll, D. C., Dromey, B., Kneip, S., Markey, K., McKenna, P., Murphy, W., Nagel, S., Willingale, L., and Zepf, M.

Abstract

Proton imaging has become a common diagnostic technique for use in laser-plasma research experiments due to their ability to diagnose electric field effects and to resolve small density differences caused through shock effects. These interactions are highly dependent on the use of radiochromic film (RCF) as a detection system for the particle probe, and produces very high-resolution images. However, saturation effects, and in many cases, damage to the film limits the usefulness of this technique for high-flux particle probing. This paper outlines the use of a new technique using contact radiography of (p,n)-generated isotopes in activation samples to produce high dynamic range 2D images with high spatial resolution and extremely high dynamic range, whilst maintaining both energy resolution and absolute flux measurements. (C)007 Elsevier B.V. All rights reserved.

Published
2008

47. Fast Fourier-Transform Second-Harmonic Generation (FFT-SHG) Provides a Solution for Measuring Nonlinear Effects on Fragile Structures

Author

Vanbel, M. K., primary, Paesen, R., additional, Brullot, W., additional, Vandendriessche, S., additional, Asselberghs, I., additional, Markey, K., additional, Valvekens, P., additional, van der Veen, M. A., additional, De Vos, D., additional, Ameloot, M., additional, Valev, V. K., additional, Locquet, J.-P., additional, and Verbiest, T., additional

Published
2013
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48. High harmonics from relativistically oscillating plasma surfaces - a high brightness attosecond source at keV photon energies

Author

Zepf, M., Dromey, B., Kar, S., Bellei, C., Carroll, D. C., Clarke, R. J., Green, J. S., Kneip, S., Markey, K., Nagel, S. R., Simpson, P. T., Willingale, L., McKenna, P., Neely, D., Najmudin, Z., Krushelnick, K., Norreys, P. A., Zepf, M., Dromey, B., Kar, S., Bellei, C., Carroll, D. C., Clarke, R. J., Green, J. S., Kneip, S., Markey, K., Nagel, S. R., Simpson, P. T., Willingale, L., McKenna, P., Neely, D., Najmudin, Z., Krushelnick, K., and Norreys, P. A.

Abstract

An intense laser pulse interacting with a near discontinuous plasma vacuum interface causes the plasma surface to perform relativistic oscillations. The reflected laser radiation then contains very high order harmonics of fundamental frequency and-according to current theory-must be bunched in radiation bursts of a few attoseconds duration. Recent experimental results have demonstrated x-ray harmonic radiation extending to 3.3 angstrom (3.8 keV, order n > 3200) with the harmonic conversion efficiency scaling as eta(n) n(-2.5) over the entire observed spectrum ranging from 17 nm to 3.3 angstrom. This scaling holds up to a maximum order, n(RO) 81 8(1/2)gamma(3), where gamma is the peak value of the Lorentz factor, above which the harmonic efficiency decreases more rapidly. The coherent nature of the generated harmonics is demonstrated by the highly directional beamed emission, which for photon energy h nu > 1 keV is found to be into a cone angle similar to 4 degrees, significantly less than that of the incident laser cone (20 degrees).

Published
2007

49. Bright multi-keV harmonic generation from relativistically oscillating plasma surfaces

Author

Dromey, B., Kar, S., Bellei, C., Carroll, D. C., Clarke, R. J., Green, J. S., Kneip, S., Markey, K., Nagel, S. R., Simpson, P. T., Willingale, L., McKenna, P., Neely, D., Najmudin, Z., Krushelnick, K., Norreys, P. A., Zepf, M., Dromey, B., Kar, S., Bellei, C., Carroll, D. C., Clarke, R. J., Green, J. S., Kneip, S., Markey, K., Nagel, S. R., Simpson, P. T., Willingale, L., McKenna, P., Neely, D., Najmudin, Z., Krushelnick, K., Norreys, P. A., and Zepf, M.

Abstract

The first evidence of x-ray harmonic radiation extending to 3.3 A, 3.8 keV (order n > 3200) from petawatt class laser-solid interactions is presented, exhibiting relativistic limit efficiency scaling (eta similar to n(-2.5)-n(-3)) at multi-keV energies. This scaling holds up to a maximum order, n(RO)similar to 8(1/2)gamma(3), where gamma is the relativistic Lorentz factor, above which the first evidence of an intensity dependent efficiency rollover is observed. The coherent nature of the generated harmonics is demonstrated by the highly directional beamed emission, which for photon energy h nu > 1 keV is found to be into a cone angle similar to 4 degrees, significantly less than that of the incident laser cone (20 degrees).

Published
2007

50. Controlling Fast-Electron-Beam Divergence Using Two Laser Pulses

Author

Scott, R. H. H., primary, Beaucourt, C., additional, Schlenvoigt, H.-P., additional, Markey, K., additional, Lancaster, K. L., additional, Ridgers, C. P., additional, Brenner, C. M., additional, Pasley, J., additional, Gray, R. J., additional, Musgrave, I. O., additional, Robinson, A. P. L, additional, Li, K., additional, Notley, M. M., additional, Davies, J. R., additional, Baton, S. D., additional, Santos, J. J., additional, Feugeas, J.-L., additional, Nicolaï, Ph., additional, Malka, G., additional, Tikhonchuk, V. T., additional, McKenna, P., additional, Neely, D., additional, Rose, S. J., additional, and Norreys, P. A., additional

Published
2012
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