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Wilson R, King M, Butler NMH, Carroll DC, Frazer TP, Duff MJ, Higginson A, Dance RJ, Jarrett J, Davidson ZE, Armstrong CD, Liu H, Hawkes SJ, Clarke RJ, Neely D, Gray RJ, McKenna P. Influence of spatial-intensity contrast in ultraintense laser-plasma interactions. Sci Rep 2022; 12:1910. [PMID: 35115579 PMCID: PMC8814164 DOI: 10.1038/s41598-022-05655-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 01/05/2022] [Indexed: 11/09/2022] Open
Abstract
Increasing the intensity to which high power laser pulses are focused has opened up new research possibilities, including promising new approaches to particle acceleration and phenomena such as high field quantum electrodynamics. Whilst the intensity achievable with a laser pulse of a given power can be increased via tighter focusing, the focal spot profile also plays an important role in the interaction physics. Here we show that the spatial-intensity distribution, and specifically the ratio of the intensity in the peak of the laser focal spot to the halo surrounding it, is important in the interaction of ultraintense laser pulses with solid targets. By comparing proton acceleration measurements from foil targets irradiated with by a near-diffraction-limited wavelength scale focal spot and larger F-number focusing, we find that this spatial-intensity contrast parameter strongly influences laser energy coupling to fast electrons. We find that for multi-petawatt pulses, spatial-intensity contrast is potentially as important as temporal-intensity contrast.
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Affiliation(s)
- R Wilson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - M King
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.,The Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - N M H Butler
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - D C Carroll
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - T P Frazer
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - M J Duff
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - A Higginson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - R J Dance
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - J Jarrett
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - Z E Davidson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - C D Armstrong
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.,Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - H Liu
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - S J Hawkes
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - R J Clarke
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - D Neely
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.,Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - R J Gray
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - P McKenna
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK. .,The Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK.
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Najmudin Z, Kneip S, Bloom MS, Mangles SPD, Chekhlov O, Dangor AE, Döpp A, Ertel K, Hawkes SJ, Holloway J, Hooker CJ, Jiang J, Lopes NC, Nakamura H, Norreys PA, Rajeev PP, Russo C, Streeter MJV, Symes DR, Wing M. Compact laser accelerators for X-ray phase-contrast imaging. Philos Trans A Math Phys Eng Sci 2014; 372:20130032. [PMID: 24470414 PMCID: PMC3900035 DOI: 10.1098/rsta.2013.0032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Advances in X-ray imaging techniques have been driven by advances in novel X-ray sources. The latest fourth-generation X-ray sources can boast large photon fluxes at unprecedented brightness. However, the large size of these facilities means that these sources are not available for everyday applications. With advances in laser plasma acceleration, electron beams can now be generated at energies comparable to those used in light sources, but in university-sized laboratories. By making use of the strong transverse focusing of plasma accelerators, bright sources of betatron radiation have been produced. Here, we demonstrate phase-contrast imaging of a biological sample for the first time by radiation generated by GeV electron beams produced by a laser accelerator. The work was performed using a greater than 300 TW laser, which allowed the energy of the synchrotron source to be extended to the 10-100 keV range.
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Affiliation(s)
- Z. Najmudin
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - S. Kneip
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - M. S. Bloom
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - S. P. D. Mangles
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - O. Chekhlov
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, UK
| | - A. E. Dangor
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - A. Döpp
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - K. Ertel
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, UK
| | - S. J. Hawkes
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, UK
| | - J. Holloway
- Department of Physics and Astronomy, University College London, London, UK
| | - C. J. Hooker
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, UK
| | - J. Jiang
- Grupo de Lasers e Plasmas, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Lisboa, Portugal
| | - N. C. Lopes
- Grupo de Lasers e Plasmas, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Lisboa, Portugal
| | - H. Nakamura
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - P. A. Norreys
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, UK
| | - P. P. Rajeev
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, UK
| | - C. Russo
- Grupo de Lasers e Plasmas, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Lisboa, Portugal
| | - M. J. V. Streeter
- John Adams Institute, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK
| | - D. R. Symes
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, UK
| | - M. Wing
- Department of Physics and Astronomy, University College London, London, UK
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Kneip S, Nagel SR, Martins SF, Mangles SPD, Bellei C, Chekhlov O, Clarke RJ, Delerue N, Divall EJ, Doucas G, Ertel K, Fiuza F, Fonseca R, Foster P, Hawkes SJ, Hooker CJ, Krushelnick K, Mori WB, Palmer CAJ, Phuoc KT, Rajeev PP, Schreiber J, Streeter MJV, Urner D, Vieira J, Silva LO, Najmudin Z. Near-GeV acceleration of electrons by a nonlinear plasma wave driven by a self-guided laser pulse. Phys Rev Lett 2009; 103:035002. [PMID: 19659287 DOI: 10.1103/physrevlett.103.035002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Indexed: 05/28/2023]
Abstract
The acceleration of electrons to approximately 0.8 GeV has been observed in a self-injecting laser wakefield accelerator driven at a plasma density of 5.5x10(18) cm(-3) by a 10 J, 55 fs, 800 nm laser pulse in the blowout regime. The laser pulse is found to be self-guided for 1 cm (>10zR), by measurement of a single filament containing >30% of the initial laser energy at this distance. Three-dimensional particle in cell simulations show that the intensity within the guided filament is amplified beyond its initial focused value to a normalized vector potential of a0>6, thus driving a highly nonlinear plasma wave.
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Affiliation(s)
- S Kneip
- The Blackett Laboratory, Imperial College London, London, SW7 2BZ, United Kingdom
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Buse K, Lalji N, Mayhew SH, Imran M, Hawkes SJ. Political feasibility of scaling-up five evidence-informed HIV interventions in Pakistan: a policy analysis. Sex Transm Infect 2009; 85 Suppl 2:ii37-42. [DOI: 10.1136/sti.2008.034058] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Paz-Bailey G, Ramaswamy M, Hawkes SJ, Geretti AM. Herpes simplex virus type 2: epidemiology and management options in developing countries. Sex Transm Infect 2006; 84:299-306. [PMID: 17098770 PMCID: PMC2598582 DOI: 10.1136/sti.2006.020966] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Genital herpes simplex virus type 2 (HSV2) is highly prevalent worldwide and an increasingly important cause of genital ulcer disease (GUD). Continued HSV2 transmission is facilitated by the large number of undiagnosed cases, the frequency of atypical disease and the occurrence of asymptomatic shedding. The lack of easy, affordable diagnostic methods and specific antiviral treatment in countries with low and middle income is of great concern, given the ability of GUD to enhance HIV transmission and acquisition. With rising HSV2 prevalence contributing to an increase in the proportion of GUD attributed to genital herpes in high-HIV prevalence settings, a safe and effective HSV vaccine is urgently needed. Meanwhile, multifaceted interventions are required to improve recognition of genital herpes, to prevent its spread and also to prevent its potential to promote HIV transmission in developing countries.
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Affiliation(s)
- G Paz-Bailey
- Global AIDS Program for Central America National Center for HIV, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
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Clarke RJ, Neely D, Edwards RD, Wright PNM, Ledingham KWD, Heathcote R, McKenna P, Danson CN, Brummitt PA, Collier JL, Hatton PE, Hawkes SJ, Hernandez-Gomez C, Holligan P, Hutchinson MHR, Kidd AK, Lester WJ, Neville DR, Norreys PA, Pepler DA, Winstone TB, Wyatt RWW, Wyborn BE. Radiological characterisation of photon radiation from ultra-high-intensity laser-plasma and nuclear interactions. J Radiol Prot 2006; 26:277-86. [PMID: 16926470 DOI: 10.1088/0952-4746/26/3/002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
With the increasing number of multi-terawatt (10(12) W) and petawatt (10(15) W) laser interaction facilities being built, the need for a detailed understanding of the potential radiological hazards is required and their impact on personnel is of major concern. Experiments at a number of facilities are being undertaken to achieve this aim. This paper describes the recent work completed on the Vulcan petawatt laser system at the CCLRC Rutherford Appleton Laboratory, where photon doses of up to 43 mSv at 1 m per shot have been measured during commissioning studies. It also overviews the shielding in place on the facility in order to comply with the Ionising Radiation Regulations 1999 (IRR99), maintaining a dose to personnel of less than 1 mSv yr(-1) and as low as reasonably practicable (ALARP).
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Affiliation(s)
- R J Clarke
- CCLRC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK.
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Hernandez-Gomez C, Collier JL, Hawkes SJ, Danson CN, Edwards CB, Pepler DA, Ross IN, Winstone TB. Wave-front control of a large-aperture laser system by use of a static phase corrector. Appl Opt 2000; 39:1954-1961. [PMID: 18345093 DOI: 10.1364/ao.39.001954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In large-aperture, ultrahigh-intensity laser systems, such as Vulcan at the Rutherford Appleton Laboratory, one of the most important factors that determines the ultimate on-target focused intensity is the wave-front quality of the laser pulse. We report on a wave-front analysis carried out on Vulcan to determine the nature and contribution of the aberrations present in the laser pulse that effectively limited the available on-target intensity. We also report on a significant improvement to the wave-front quality that was achieved by static correction of the main aberration, resulting in an increase of focused intensities by a factor of 4.
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Affiliation(s)
- C Hernandez-Gomez
- Rutherford Appleton Laboratory, Central Laboratory of the Research Councils, Chilton, Didcot, Oxon OX11 0QX, UK.
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Low NM, Hawkes SJ. Rising HIV-1 prevalence in STD clinic attenders in Jamaica; traumatic sex and genital ulcers as risk factors. J Acquir Immune Defic Syndr Hum Retrovirol 1995; 8:214-6. [PMID: 7834408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Abstract
This is a review of recent publications on the subject of travel (taken in its widest sense) and HIV/AIDS. As with all epidemics caused by transmissible pathogens, AIDS has been seen in many countries as an imported problem. What this perspective fails to recognize is that with the explosion of international travel in the past thirty years it is virtually impossible to prevent the spread of infectious disease across international frontiers. Here we highlight the relative paucity of studies that describe or investigate the context in which sexual risk behaviour of travellers takes place, and suggest areas of further research which could increase understanding of the nature of sexual risk taking, and help in the design of health education programmes.
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Affiliation(s)
- S J Hawkes
- Academic Department of Genito-Urinary Medicine, University College and Middlesex School of Medicine, Middlesex Hospital, London, United Kingdom
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Winder WW, Loy SF, Burke DS, Hawkes SJ. Liver glycogenolysis during exercise in adrenodemedullated male and female rats. Am J Physiol 1986; 251:R1151-5. [PMID: 3024510 DOI: 10.1152/ajpregu.1986.251.6.r1151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Previous studies have shown that adrenodemedullation has no effect on the rate of liver glycogenolysis during exercise in male rats. Mature female rats have been reported to have a higher hepatic beta-adrenergic receptor activity than do male rats of the same age. The present study was undertaken to determine the role of plasma epinephrine in stimulating liver glycogenolysis during exercise in female rats. Both male and female rats were adrenodemedullated or sham operated. Three weeks later rats were run for 60 min at 21 m/min up a 15% grade. The rate of liver glycogenolysis during exercise was not affected by adrenodemedullation in either female rats or male rats. Hepatic adenosine 3',5'-cyclic monophosphate increased to approximately the same extent in sham operated as in adrenodemedullated female rats during exercise. Adrenodemedullation caused a significant reduction in the amount of glycogen utilized by the soleus muscle and in the degree of hyperglycemia during exercise. We conclude that epinephrine is unessential for stimulation of liver glycogenolysis during exercise in either male or female rats.
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Hawkes SJ. Letters to the Editor. J Chromatogr Sci 1979. [DOI: 10.1093/chromsci/17.11.640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Hawkes EC, Hawkes SJ. Variation of Retention Volume with Molecular Weight of Polyethylene Glycol and with Carbon Number of n-Alkanols. J Chromatogr Sci 1979; 17:285-6. [DOI: 10.1093/chromsci/17.5.285] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Roberts GL, Hawkes SJ. Definition of the Activity Coefficient for Polymeric Liquid Phases: Regression Equations for Retention Data of Homologous Series. J Chromatogr Sci 1973. [DOI: 10.1093/chromsci/11.1.16] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Hartmann N, Hawkes SJ. Statistical Analysis of Multivariate Chromatographic Data on Natural Mixtures, with Particular Reference to Peppermint Oils. J Chromatogr Sci 1970. [DOI: 10.1093/chromsci/8.10.610] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Hawkes SJ, Steed SP. Packing Structure, Obstruction Factors, Flow Laminarity and Permeability in Chromosorb and Bead Packings. J Chromatogr Sci 1970. [DOI: 10.1093/chromsci/8.5.256] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Hawkes SJ. Analytical Technique:
The Practice of Gas Chromatography
. Leslie S. Ettre and Albert Zlatikis, Eds. Interscience (Wiley), New York, 1967. xvi + 591 pp., illus. $14.95. Science 1968. [DOI: 10.1126/science.161.3847.1235-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- S. J. Hawkes
- Department of Chemistry, Brigham Young University, Provo, Utah
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Hawkes SJ. Analytical Technique:
The Practice of Gas Chromatography
. Leslie S. Ettre and Albert Zlatikis, Eds. Interscience (Wiley), New York, 1967. xvi + 591 pp., illus. $14.95. Science 1968. [DOI: 10.1126/science.161.3847.1235.b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- S. J. Hawkes
- Department of Chemistry, Brigham Young University, Provo, Utah
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