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Szatmári S, Nagy T, Dajka R, Kedves MÁ, Aladi M, Földes IB. Temporal contrast enhancement of a Ti:Sapphire laser by nonlinear Fourier filtering. OPTICS EXPRESS 2024; 32:17038-17047. [PMID: 38858896 DOI: 10.1364/oe.521567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/14/2024] [Indexed: 06/12/2024]
Abstract
Temporal cleaning of high-power infrared (IR) pulses generated by a Ti:Sapphire system is demonstrated by the use of the Nonlinear Fourier Filtering (NFF) method. In a proof-of-principle experiment suppression of up to 1000 is achieved for the temporal pedestal prior to the main pulse, with a moderate (20-25%) overall throughput. This includes the same suppression ratio for the picosecond coherent pedestal in the direct vicinity of the main pulse. Based on the instantaneous, intensity-dependent and high-order switching characteristics of NFF, excellent pulse cleaning performance is observed. The efficient, high-contrast removal of the coherent pedestal from the foot of the main pulse even if its duration is shorter than 100 fs is compared with the capability of the plasma mirror technique. Calculations are also performed, supporting the experimentally observed sharp intensity dependence of the switching process, pointing out the dominant role of the ionization-based refractive index change.
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Generation of Intense and Temporally Clean Pulses—Contrast Issues of High-Brightness Excimer Systems. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12042064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In high-brightness excimer systems, the direct amplification of short pulses allows temporal filters to be integral parts of the ultraviolet (UV) amplifier chain, where the only origin of the noise is the amplified spontaneous emission (ASE), generated by the amplifier(s) following the filter. The ASE, however, develops faster than the short main pulse; in this paper, the dynamic short- and long-pulse amplification properties of KrF, XeCl and XeF excimers are studied, with special emphasis on the temporal contrast. It was found that, beyond the saturation of amplification, the relaxation of the B state in KrF, together with the contribution of the absorption of the transiently populated X state in XeCl and XeF, are the main limitations for both the extraction efficiency and the contrast. For all excimers, the stimulated transition rates and the dependence of the achievable contrast on the level of saturation were derived. Local quantities were introduced to characterize the deterioration of the contrast for a unit gain length of KrF amplifiers. A KrF power amplifier of limited gain (G ≈ 3), following the newly introduced nonlinear Fourier filter, is capable of reaching contrast levels beyond the previously reported 1011–1012.
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3
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Current Progress in Femtosecond Laser Ablation/Ionisation Time-of-Flight Mass Spectrometry. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11062562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The last decade witnessed considerable progress in the development of laser ablation/ionisation time-of-flight mass spectrometry (LI-TOFMS). The improvement of both the laser ablation ion sources employing femtosecond lasers and the method of ion coupling with the mass analyser led to highly sensitive element and isotope measurements, minimisation of matrix effects, and reduction of various fractionation effects. This improvement of instrumental performance can be attributed to the progress in laser technology and accompanying commercialisation of fs-laser systems, as well as the availability of fast electronics and data acquisition systems. Application of femtosecond laser radiation to ablate the sample causes negligible thermal effects, which in turn allows for improved resolution of chemical surface imaging and depth profiling. Following in the footsteps of its predecessor ns-LIMS, fs-LIMS, which employs fs-laser ablation ion sources, has been developed in the last two decades as an important method of chemical analysis and will continue to improve its performance in subsequent decades. This review discusses the background of fs-laser ablation, overviews the most relevant instrumentation and emphasises their performance figures, and summarizes the studies on several applications, including geochemical, semiconductor, and bio-relevant materials. Improving the chemical analysis is expected by the implementation of laser pulse sequences or pulse shaping methods and shorter laser wavelengths providing current progress in mass resolution achieved in fs-LIMS. In parallel, advancing the methods of data analysis has the potential of making this technique very attractive for 3D chemical analysis with micrometre lateral and sub-micrometre vertical resolution.
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Choi IW, Jeon C, Lee SG, Kim SY, Kim TY, Kim IJ, Lee HW, Woo Yoon J, Sung JH, Lee SK, Nam CH. Highly efficient double plasma mirror producing ultrahigh-contrast multi-petawatt laser pulses. OPTICS LETTERS 2020; 45:6342-6345. [PMID: 33258807 DOI: 10.1364/ol.409749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/22/2020] [Indexed: 06/12/2023]
Abstract
We present a highly efficient double plasma mirror (DPM) that provides ultrahigh-contrast multi-petawatt (PW) laser pulses with a temporal contrast ratio reaching 1017 up to 160 ps and 1012 up to 2 ps before the main pulse. The high reflectivity of 70%, along with the high-contrast enhancement factor of 700,000, was achieved from the DPM installed after the final stage of a 4 PW Ti:sapphire laser. The 4 PW laser was equipped with cross-polarized wave generation and optical parametric chirped-pulse amplification stages for initial high-contrast operation. The DPM operation was undertaken with conditions that did not modify the spatiotemporal profiles of incident multi-PW laser pulses. This highly efficient DPM with the high-contrast enhancement promises the utilization of multiple PMs as a practical rear end for upcoming tens of petawatt lasers to achieve ultrahigh temporal contrast.
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Martynenko AS, Pikuz SA, Skobelev IY, Ryazantsev SN, Baird C, Booth N, Doehl L, Durey P, Faenov AY, Farley D, Kodama R, Lancaster K, McKenna P, Murphy CD, Spindloe C, Pikuz TA, Woolsey N. Effect of plastic coating on the density of plasma formed in Si foil targets irradiated by ultra-high-contrast relativistic laser pulses. Phys Rev E 2020; 101:043208. [PMID: 32422777 DOI: 10.1103/physreve.101.043208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/13/2020] [Indexed: 11/07/2022]
Abstract
The formation of high energy density matter occurs in inertial confinement fusion, astrophysical, and geophysical systems. In this context, it is important to couple as much energy as possible into a target while maintaining high density. A recent experimental campaign, using buried layer (or "sandwich" type) targets and the ultrahigh laser contrast Vulcan petawatt laser facility, resulted in 500 Mbar pressures in solid density plasmas (which corresponds to about 4.6×10^{7}J/cm^{3} energy density). The densities and temperatures of the generated plasma were measured based on the analysis of x-ray spectral line profiles and relative intensities.
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Affiliation(s)
- A S Martynenko
- Joint Institute for High Temperatures of Russian Academy of Sciences, 125412 Moscow, Russia.,National Research Nuclear University MEPhI, Kashirskoe Sh. 31, 115409 Moscow, Russia
| | - S A Pikuz
- Joint Institute for High Temperatures of Russian Academy of Sciences, 125412 Moscow, Russia.,National Research Nuclear University MEPhI, Kashirskoe Sh. 31, 115409 Moscow, Russia
| | - I Yu Skobelev
- Joint Institute for High Temperatures of Russian Academy of Sciences, 125412 Moscow, Russia.,National Research Nuclear University MEPhI, Kashirskoe Sh. 31, 115409 Moscow, Russia
| | - S N Ryazantsev
- Joint Institute for High Temperatures of Russian Academy of Sciences, 125412 Moscow, Russia.,National Research Nuclear University MEPhI, Kashirskoe Sh. 31, 115409 Moscow, Russia
| | - C Baird
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, England, United Kingdom
| | - N Booth
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, England, United Kingdom
| | - L Doehl
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, England, United Kingdom
| | - P Durey
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, England, United Kingdom
| | - A Ya Faenov
- Joint Institute for High Temperatures of Russian Academy of Sciences, 125412 Moscow, Russia.,Open and Transdisciplinary Research Initiative, Osaka University, Osaka 565-0871, Japan
| | - D Farley
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, England, United Kingdom
| | - R Kodama
- Open and Transdisciplinary Research Initiative, Osaka University, Osaka 565-0871, Japan.,Institute of Laser Engineering, Osaka University, Suita 565-0871, Japan
| | - K Lancaster
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, England, United Kingdom
| | - P McKenna
- Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG, Scotland, United Kingdom
| | - C D Murphy
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, England, United Kingdom
| | - C Spindloe
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, England, United Kingdom
| | - T A Pikuz
- Joint Institute for High Temperatures of Russian Academy of Sciences, 125412 Moscow, Russia.,Open and Transdisciplinary Research Initiative, Osaka University, Osaka 565-0871, Japan
| | - N Woolsey
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, England, United Kingdom
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Edghill B, Forestier-Colleoni P, Park J, Rubenchik A, Beg FN, Ma T. Plasma mirror focal spot quality for glass and aluminum mirrors for laser pulses up to 20 ps. OPTICS LETTERS 2020; 45:1228-1231. [PMID: 32108812 DOI: 10.1364/ol.385326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/20/2020] [Indexed: 06/10/2023]
Abstract
High-intensity short-pulse lasers are being pushed further as applications continue to demand higher laser intensities. Uses such as radiography and laser-driven particle acceleration require these higher intensities to produce the necessary x-ray and particle fluxes. Achieving these intensities, however, is limited by the damage threshold of costly optics and the complexity of target chambers. This is evidenced by the Advanced Radiographic Capability (ARC) short-pulse laser at the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory, producing four high-energy $ \approx 1\;{\rm kJ} $≈1kJ laser pulses at 30 ps pulse duration, being limited to an intensity of $ {10^{18}}\;{\rm W}/{{\rm cm}^2} $1018W/cm2 by the large focal spot size of $ \approx 100\;{\unicode{x00B5}{\rm m}} $≈100µm. Due to the setup complexity of NIF, changing the location of the final focusing parabola in order to improve the focal spot size is not an option. This leads to the possible use of disposable ellipsoidal plasma mirrors (PMs) placed within the chamber, close to the target in an attempt to refocus the four ARC beams. However, the behavior of PMs at these relatively long pulse durations (tens of picoseconds) is not well characterized. The results from the COMET laser at the Jupiter Laser Facility carried out at 0.5 to 20 ps pulse durations on flat mirrors are presented as a necessary first step towards focusing curved mirrors. The findings show defocusing at longer pulse durations and higher intensities, with less degradation when using aluminum coated mirrors.
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7
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Gilicze B, Homik Z, Szatmári S. High-contrast, high-brightness ultraviolet laser system. OPTICS EXPRESS 2019; 27:17377-17386. [PMID: 31252948 DOI: 10.1364/oe.27.017377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/07/2019] [Indexed: 06/09/2023]
Abstract
In this paper, improved operation of a high-contrast, high-brightness ultraviolet laser system is described. The laser system is based on a conventional short-pulse dye/excimer design, modified to contain 3 KrF excimer short-pulse amplifiers and the recently developed nonlinear Fourier-filtering stage for contrast improvement. The final amplifier accepts a beam size of ~4x4 cm2, producing 100 mJ energy of short-pulses using a two-beam interferometric multiplexing setup. Temporal measurements of the output showed positively chirped pulses of ~700 fs duration, beside a focusability of ~2 times the diffraction limit. Amplified spontaneous emission-as the only source of the temporal background-results in a focused intensity contrast of >1012 in the entire temporal window. These unique parameters give access to laser-matter interaction experiments above 1019 W/cm2 intensity at 248 nm.
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Gilicze B, Dajka R, Földes IB, Szatmári S. Improvement of the temporal and spatial contrast of the nonlinear Fourier-filter. OPTICS EXPRESS 2017; 25:20791-20797. [PMID: 29041757 DOI: 10.1364/oe.25.020791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/09/2017] [Indexed: 06/07/2023]
Abstract
Recently a novel method called nonlinear Fourier-filtering was suggested for temporal and spatial cleaning of high-brightness laser pulses. In this paper experimental demonstration of the associated spatial filtering of this method and significant improvement of the temporal filtering feature are presented. The formerly found limit of ~103 for the temporal contrast improvement is identified as diffraction effects caused by the limited numerical aperture of imaging. It is shown by numerical simulation that proper apodization of the object can lead to sufficiently higher limit (>108). Using an advanced experimental arrangement the improvement of >2 orders of magnitude is experimentally verified in the ultraviolet and an indirect proof is presented that the background caused by the optical arrangement is reduced below 10-7.
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9
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Experiment and simulation of novel liquid crystal plasma mirrors for high contrast, intense laser pulses. Sci Rep 2016; 6:32041. [PMID: 27557592 PMCID: PMC4997343 DOI: 10.1038/srep32041] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/01/2016] [Indexed: 11/08/2022] Open
Abstract
We describe the first demonstration of plasma mirrors made using freely suspended, ultra-thin films formed dynamically and in-situ. We also present novel particle-in-cell simulations that for the first time incorporate multiphoton ionization and dielectric models that are necessary for describing plasma mirrors. Dielectric plasma mirrors are a crucial component for high intensity laser applications such as ion acceleration and solid target high harmonic generation because they greatly improve pulse contrast. We use the liquid crystal 8CB and introduce an innovative dynamic film formation device that can tune the film thickness so that it acts as its own antireflection coating. Films can be formed at a prolonged, high repetition rate without the need for subsequent realignment. High intensity reflectance above 75% and low-field reflectance below 0.2% are demonstrated, as well as initial ion acceleration experimental results that demonstrate increased ion energy and yield on shots cleaned with these plasma mirrors.
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Borisov AB, McCorkindale JC, Poopalasingam S, Longworth JW, Simon P, Szatmári S, Rhodes CK. Rewriting the rules governing high intensity interactions of light with matter. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:046401. [PMID: 27007146 DOI: 10.1088/0034-4885/79/4/046401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The trajectory of discovery associated with the study of high-intensity nonlinear radiative interactions with matter and corresponding nonlinear modes of electromagnetic propagation through material that have been conducted over the last 50 years can be presented as a landscape in the intensity/quantum energy [I-ħω] plane. Based on an extensive series of experimental and theoretical findings, a universal zone of anomalous enhanced electromagnetic coupling, designated as the fundamental nonlinear domain, can be defined. Since the lower boundaries of this region for all atomic matter correspond to ħω ~ 10(3) eV and I ≈ 10(16) W cm(-2), it heralds a future dominated by x-ray and γ-ray studies of all phases of matter including nuclear states. The augmented strength of the interaction with materials can be generally expressed as an increase in the basic electromagnetic coupling constant in which the fine structure constant α → Z(2)α, where Z denotes the number of electrons participating in an ordered response to the driving field. Since radiative conditions strongly favoring the development of this enhanced electromagnetic coupling are readily produced in self-trapped plasma channels, the processes associated with the generation of nonlinear interactions with materials stand in natural alliance with the nonlinear mechanisms that induce confined propagation. An experimental example involving the Xe (4d(10)5s(2)5p(6)) supershell for which Z ≅ 18 that falls in the specified anomalous nonlinear domain is described. This yields an effective coupling constant of Z(2)α ≅ 2.4 > 1, a magnitude comparable to the strong interaction and a value rendering as useless conventional perturbative analyses founded on an expansion in powers of α. This enhancement can be quantitatively understood as a direct consequence of the dominant role played by coherently driven multiply-excited states in the dynamics of the coupling. It is also conclusively demonstrated by an abundance of data that the utterly peerless champion of the experimental campaign leading to the definition of the fundamental nonlinear domain was excimer laser technology. The basis of this unique role was the ability to satisfy simultaneously a triplet (ω, I, P) of conditions stating the minimal values of the frequency ω, intensity I, and the power P necessary to enable the key physical processes to be experimentally observed and controllably combined. The historical confluence of these developments creates a solid foundation for the prediction of future advances in the fundamental understanding of ultra-high power density states of matter. The atomic findings graciously generalize to the composition of a nuclear stanza expressing the accessibility of the nuclear domain. With this basis serving as the launch platform, a cadenza of three grand challenge problems representing both new materials and new interactions is presented for future solution; they are (1) the performance of an experimental probe of the properties of the vacuum state associated with the dark energy at an intensity approaching the Schwinger/Heisenberg limit, (2) the attainment of amplification in the γ-ray region (~1 MeV) and the discovery of a nuclear excimer, and (3) the determination of a path to the projected super-heavy nuclear island of stability.
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Affiliation(s)
- Alex B Borisov
- Laboratory for X-Ray Microimaging and Bioinformatics, Department of Physics, University of Illinois at Chicago, Chicago, IL 60607-7059, USA
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11
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Kaganovich D, Peñano JR, Helle MH, Gordon DF, Hafizi B, Ting A. Origin and control of the subpicosecond pedestal in femtosecond laser systems. OPTICS LETTERS 2013; 38:3635-3638. [PMID: 24104833 DOI: 10.1364/ol.38.003635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The picosecond time scale pedestal of a multiterawatt femtosecond laser pulse is investigated experimentally and analytically. The origin of the pedestal is related to the finite bandwidth of the laser system. By deliberately introducing a modulated spectrum with minima that match this limited bandwidth, the pedestal can be reduced, with no deleterious effect on the main pulse. Using this technique, we experimentally demonstrate a subpicosecond scale order of magnitude enhancement of contrast ratio while preserving the energy in the main pulse.
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12
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Bang W, Dyer G, Quevedo HJ, Bernstein AC, Gaul E, Donovan M, Ditmire T. Optimization of the neutron yield in fusion plasmas produced by Coulomb explosions of deuterium clusters irradiated by a petawatt laser. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:023106. [PMID: 23496630 DOI: 10.1103/physreve.87.023106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Revised: 01/28/2013] [Indexed: 06/01/2023]
Abstract
The kinetic energy of hot (multi-keV) ions from the laser-driven Coulomb explosion of deuterium clusters and the resulting fusion yield in plasmas formed from these exploding clusters has been investigated under a variety of conditions using the Texas Petawatt laser. An optimum laser intensity was found for producing neutrons in these cluster fusion plasmas with corresponding average ion energies of 14 keV. The substantial volume (1-10 mm(3)) of the laser-cluster interaction produced by the petawatt peak power laser pulse led to a fusion yield of 1.6×10(7) neutrons in a single shot with a 120 J, 170 fs laser pulse. Possible effects of prepulses are discussed.
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Affiliation(s)
- W Bang
- Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712, USA.
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13
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Macphee AG, Divol L, Kemp AJ, Akli KU, Beg FN, Chen CD, Chen H, Hey DS, Fedosejevs RJ, Freeman RR, Henesian M, Key MH, Le Pape S, Link A, Ma T, Mackinnon AJ, Ovchinnikov VM, Patel PK, Phillips TW, Stephens RB, Tabak M, Town R, Tsui YY, Van Woerkom LD, Wei MS, Wilks SC. Limitation on prepulse level for cone-guided fast-ignition inertial confinement fusion. PHYSICAL REVIEW LETTERS 2010; 104:055002. [PMID: 20366771 DOI: 10.1103/physrevlett.104.055002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Indexed: 05/29/2023]
Abstract
The viability of fast-ignition (FI) inertial confinement fusion hinges on the efficient transfer of laser energy to the compressed fuel via multi-MeV electrons. Preformed plasma due to the laser prepulse strongly influences ultraintense laser plasma interactions and hot electron generation in the hollow cone of an FI target. We induced a prepulse and consequent preplasma in copper cone targets and measured the energy deposition zone of the main pulse by imaging the emitted K_{alpha} radiation. Simulation of the radiation hydrodynamics of the preplasma and particle in cell modeling of the main pulse interaction agree well with the measured deposition zones and provide an insight into the energy deposition mechanism and electron distribution. It was demonstrated that a under these conditions a 100 mJ prepulse eliminates the forward going component of approximately 2-4 MeV electrons.
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Affiliation(s)
- A G Macphee
- Lawrence Livermore National Laboratory, Livermore, California, USA.
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14
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Giguère D, Olivié G, Vidal F, Toetsch S, Girard G, Ozaki T, Kieffer JC, Nada O, Brunette I. Laser ablation threshold dependence on pulse duration for fused silica and corneal tissues: experiments and modeling. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2007; 24:1562-8. [PMID: 17491624 DOI: 10.1364/josaa.24.001562] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The surface ablation threshold fluence of fused silica and two porcine cornea layers, the epithelium and the stroma, is characterized as a function of the laser pulse duration in the range of 100 fs-5 ps for a wavelength of 800 nm (Ti:sapphire laser system). The plateaulike region observed between 100 fs and 1 ps for the corneal layers indicates that for use in laser surgery, laser pulse durations chosen within this range should be practically equivalent. Our model predicts that the ablation threshold will decrease rapidly for pulse durations in the low end of the femtosecond regime.
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Affiliation(s)
- Dominic Giguère
- Institut National de la Recherche Scientifique-Energie, Matériaux et Télécommunications, Varennes, Quebec, Canada
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15
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Khattak FY, Percie du Sert OAMB, Riley D, Foster PS, Divall EJ, Hooker CJ, Langley AJ, Smith J, Gibbon P. Comparison of experimental and simulated Kalpha yield for 400 nm ultrashort pulse laser irradiation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 74:027401. [PMID: 17025569 DOI: 10.1103/physreve.74.027401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Indexed: 05/12/2023]
Abstract
Ti Kalpha emission yields from foils irradiated with approximately 45 fs, p-polarized pulses of a frequency-doubled Ti:sapphire laser are presented. A simple model invoking vacuum heating to predict absorption and hot electron temperature was coupled with the cross section for K -shell ionization of Ti and the Bethe-Bloch stopping power equation for electrons. The peak predicted Kalpha emission was in generally good agreement with experiment. This contrasts strongly with previous work at the fundamental frequency. Similar predictions using particle-in-cell (PIC) code simulation to estimate the number and temperature of hot electrons also gave good agreement for yield.
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Affiliation(s)
- F Y Khattak
- School of Mathematics and Physics, Queen's University of Belfast, University Road, Belfast BT7 1NN, United Kingdom
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16
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Dobosz S, Doumy G, Stabile H, D'Oliveira P, Monot P, Réau F, Hüller S, Martin P. Probing hot and dense laser-induced plasmas with ultrafast XUV pulses. PHYSICAL REVIEW LETTERS 2005; 95:025001. [PMID: 16090690 DOI: 10.1103/physrevlett.95.025001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Indexed: 05/03/2023]
Abstract
In this Letter, we demonstrate the instantaneous creation of a hot solid-density plasma generated by focusing an intense femtosecond, high temporal contrast laser on an ultrathin foil (100 nm) in the 10(18) W/cm2 intensity range. The use of high-order harmonics generated in a gas jet, providing a probe beam of sufficiently short wavelengths to penetrate such a medium, enables the study of the dynamics of this plasma on the 100 fs time scale. The comparison of the transmission of two successive harmonics permits us to determine the electronic density and the temperature with accuracies better than 15%, never achieved up to this date in the regime of laser pulses at relativistic intensity.
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Affiliation(s)
- S Dobosz
- Service des Photons, Atomes et Molécules, Commissariat à l'Energie Atomique, DSM/DRECAM, CEN Saclay, 91191 Gif sur Yvette, France
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17
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Riley D, Angulo-Gareta JJ, Khattak FY, Lamb MJ, Foster PS, Divall EJ, Hooker CJ, Langley AJ, Clarke RJ, Neely D. Kalpha yields from Ti foils irradiated with ultrashort laser pulses. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:016406. [PMID: 15697734 DOI: 10.1103/physreve.71.016406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Indexed: 05/24/2023]
Abstract
We have studied the emission of Kalpha radiation from Ti foils irradiated with ultrashort (45 fs) laser pulses. We utilized the fundamental (800 nm) light from a Ti:sapphire laser on bare foils and foils coated with a thin layer of parylene E (CH). The focusing was varied widely to give a range of intensities from approximately 10(15) - 10(19) W cm(-2). Our results show a conversion efficiency of laser to Kalpha energy of approximately 10(-4) at tight focus for both types of targets. In addition, the coated targets exhibited strong secondary peaks of conversion at large defocus, which we believe are due to modification of the extent of preformed plasma due to the dielectric nature of the plastic layer. This in turn affects the level of resonance absorption. A simple model of Kalpha production predicts a much higher conversion than seen experimentally and possible reasons for this are discussed.
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Affiliation(s)
- D Riley
- School of Mathematics and Physics, Queen's University of Belfast, University Road, Belfast, BT7 1NN, Northern Ireland.
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Ditmire T, Bless S, Dyer G, Edens A, Grigsby W, Hays G, Madison K, Maltsev A, Colvin J, Edwards M, Lee R, Patel P, Price D, Remington B, Sheppherd R, Wootton A, Zweiback J, Liang E, Kielty K. Overview of future directions in high energy-density and high-field science using ultra-intense lasers. Radiat Phys Chem Oxf Engl 1993 2004. [DOI: 10.1016/j.radphyschem.2003.12.042] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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