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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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Nersisyan G, Makita M, McKeever K, Dzelzainis T, White S, Nedanovska E, Kettle B, Nicholl R, Williams G, Riley D, Lewis CLS. Electron refluxing and K-shell line emission from Ti foils irradiated with subpicosecond laser pulses at 527 nm. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:056415. [PMID: 23004887 DOI: 10.1103/physreve.85.056415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Indexed: 06/01/2023]
Abstract
We present data on emission of K-shell radiation from Ti foils irradiated with subpicosecond pulses of second harmonic radiation (527 nm) from the TARANIS laser system at intensities of up to 10(18) W cm(-2). The data are used to demonstrate that a resonance absorption type mechanism is responsible for absorption of the laser light and to estimate fast electron temperatures of 30-60 keV that are in broad agreement with expectation from models of absorption for a steep density gradient. Data taken with resin-backed targets are used to demonstrate clear evidence of electron refluxing even at the modest fast electron temperatures inferred.
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Affiliation(s)
- G Nersisyan
- Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, United Kingdom
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3
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Lu W, Nicoul M, Shymanovich U, Tarasevitch A, Zhou P, Sokolowski-Tinten K, von der Linde D, Masek M, Gibbon P, Teubner U. Optimized Kalpha x-ray flashes from femtosecond-laser-irradiated foils. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 80:026404. [PMID: 19792265 DOI: 10.1103/physreve.80.026404] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Indexed: 05/28/2023]
Abstract
We investigate the generation of ultrashort Kalpha pulses from plasmas produced by intense femtosecond p-polarized laser pulses on Copper and Titanium targets. Particular attention is given to the interplay between the angle of incidence of the laser beam on the target and a controlled prepulse. It is observed experimentally that the Kalpha yield can be optimized for correspondingly different prepulse and plasma scale-length conditions. For steep electron-density gradients, maximum yields can be achieved at larger angles. For somewhat expanded plasmas expected in the case of laser pulses with a relatively poor contrast, the Kalpha yield can be enhanced by using a near-normal-incidence geometry. For a certain scale-length range (between 0.1 and 1 times a laser wavelength) the optimized yield is scale-length independent. Physically this situation arises because of the strong dependence of collisionless absorption mechanisms-in particular resonance absorption-on the angle of incidence and the plasma scale length, giving scope to optimize absorption and hence the Kalpha yield. This qualitative description is supported by calculations based on the classical resonance absorption mechanism and by particle-in-cell simulations. Finally, the latter simulations also show that even for initially steep gradients, a rapid profile expansion occurs at oblique angles in which ions are pulled back toward the laser by hot electrons circulating at the front of the target. The corresponding enhancement in Kalpha yield under these conditions seen in the present experiment represents strong evidence for this suprathermal shelf formation effect.
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Affiliation(s)
- W Lu
- Institut für Experimentelle Physik, Universität Duisburg-Essen, D-47048 Duisburg, Germany
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Chen LM, Kando M, Xu MH, Li YT, Koga J, Chen M, Xu H, Yuan XH, Dong QL, Sheng ZM, Bulanov SV, Kato Y, Zhang J, Tajima T. Study of x-ray emission enhancement via a high-contrast femtosecond laser interacting with a solid foil. PHYSICAL REVIEW LETTERS 2008; 100:045004. [PMID: 18352290 DOI: 10.1103/physrevlett.100.045004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Indexed: 05/26/2023]
Abstract
We observed the increase of the conversion efficiency from laser energy to Kalpha x-ray energy (eta(K)) produced by a 60 fs frequency doubled high-contrast laser pulse focused on a Cu foil, compared to the case of the fundamental laser pulse. eta(K) shows a strong dependence on the nonlinearly modified rising edge of the laser pulse. It reaches a maximum for a 100 fs negatively modified pulse. The hot electron efficient heating leads to the enhancement of eta(K). This demonstrates that high-contrast lasers are an effective tool for optimizing eta(K), via increasing the hot electrons by vacuum heating.
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Affiliation(s)
- L M Chen
- Advanced Photon Research Center, Kansai Photon Science Institute, JAEA, Kyoto 619-0215, Japan
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Chen H, Shepherd R, Chung HK, Kemp A, Hansen SB, Wilks SC, Ping Y, Widmann K, Fournier KB, Dyer G, Faenov A, Pikuz T, Beiersdorfer P. Fast-electron-relaxation measurement for laser-solid interaction at relativistic laser intensities. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:056402. [PMID: 18233771 DOI: 10.1103/physreve.76.056402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 09/25/2007] [Indexed: 05/25/2023]
Abstract
We present measurements of the fast-electron-relaxation time in short-pulse (0.5 ps) laser-solid interactions for laser intensities of 10(17), 10(18), and 10(19) Wcm2, using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. We find that the laser coupling to hot electrons increases as the laser intensity becomes relativistic, and that the thermalization of fast electrons occurs over time scales on the order of 10 ps at all laser intensities. The experimental data are analyzed using a combination of models that include Kalpha generation, collisional coupling, and plasma expansion.
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Affiliation(s)
- H Chen
- Physics and Advanced Technologies, Lawrence Livermore National Laboratory, University of California, Livermore, California 94550, USA
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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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