Increased efficiency of short-pulse laser-generated proton beams from novel flat-top cone targets

Flippo, K. A.; d'Humières, E.; Gaillard, S. A.; Rassuchine, J.; Gautier, D. C.; Schollmeier, M.; Nürnberg, F.; Kline, J. L.; Adams, J.; Albright, B.; Bakeman, M.; Harres, K.; Johnson, R. P.; Korgan, G.; Letzring, S.; Malekos, S.; Renard-LeGalloudec, N.; Sentoku, Y.; Shimada, T.; Roth, M.
May 2008
Physics of Plasmas;May2008, Vol. 15 Issue 5, p056709
Academic Journal
Ion-driven fast ignition (IFI) may have significant advantages over electron-driven FI due to the potentially large reduction in the amount of energy required for the ignition beam and the laser driver. Recent experiments at the Los Alamos National Laboratory’s Trident facility employing novel Au flat-top cone targets have produced a fourfold increase in laser-energy to ion-energy efficiency, a 13-fold increase in the number of ions above 10 MeV, and a few times increase in the maximum ion energy compared to Au flat-foil targets. Compared to recently published scaling laws, these gains are even greater. If the efficiency scales with intensity in accordance to flat-foil scaling, then, with little modification, these targets can be used to generate the pulse of ions needed to ignite thermonuclear fusion in the fast ignitor scheme. A proton energy of at least 30 MeV was measured from the flat-top cone targets, and particle-in-cell (PIC) simulations show that the maximum cutoff energy may be as high as 40–45 MeV at modest intensity of 1×1019 W/cm2 with 20 J in 600 fs. Simulations indicate that the observed energy and efficiency increase can be attributed to the cone target’s ability to guide laser light into the neck to produce hot electrons and transport these electrons to the flat-top of the cone where they can be heated to much higher temperatures, creating a hotter, denser sheath. The PIC simulations also elucidate the critical parameters for obtaining superior proton acceleration such as the dependence on laser contrast/plasma prefill, as well as longitudinal and transverse laser pointing, and cone geometry. These novel cones have the potential to revolutionize inertial confinement fusion target design and fabrication via their ability to be mass produced. In addition, they could have an impact on the general physics community studying basic electron and radiation transport phenomena or as better sources of particle beams to study equations of state and warm dense matter, or for hadron therapy, as new radioisotope generators, or for compact proton radiography sources.


Related Articles

  • Ultrashort laser pulse absorption and target heating. Bochkarev, S. G.; Rozmus, W.; Brantov, A. V.; Bychenkov, V. Yu.; Sherlock, M. // AIP Conference Proceedings;7/25/2009, Vol. 1153 Issue 1, p25 

    The problem of ultrashort laser pulse absorption at the sharp plasma-vacuum interface has been solved using a new expression for plasma permittivity. The electron response includes both collisional and collisionless dissipative effects in a plasma with arbitrary ion charge. The difference...

  • An ultraviolet nanosecond light pulse generator using a light emitting diode for test of... Araki, Tsutomu; Fujisawa, Yasumitsu; Hashimot, Mamoru // Review of Scientific Instruments;Mar97, Vol. 68 Issue 3, p1365 

    Develops an optical function pulse generator that emits short pulse of duration, double pulse with variable time interval and square waveform pulse of variable width in nanosecond range. Double heterostructure light emitting diode (LED); Phenomenon used to realize a pulsed ultraviolet light...

  • Energetic electrons and protons generated from the interaction of ultrashort laser pulses with microdroplet plasmas. Jun Zheng; Zheng-Ming Sheng; Xiao-Yu Peng; Jie Zhang // Physics of Plasmas;Nov2005, Vol. 12 Issue 11, p113105 

    Generation of fast electrons and protons from ultrashort laser interactions with microdroplet plasmas has been simulated by two-dimensional particle-in-cell simulations. At weakly relativistic laser intensities, two jets of hot electrons are found to emit symmetrically in the backward direction...

  • Monolithic nonlinear transmission lines for ultrashort and moderate pulse reflectometry (abstract) Zhang, W.-M.; Hsia, R. P.; Chen, Z.-T.; Jiang, F.; Domlet, C. W.; Luhmann, Jr., N. C. // Review of Scientific Instruments;Jan1997, Vol. 68 Issue 1, p427 

    Presents an abstract of a paper describing the use of monolithic nonlinear transmission lines (NLTL) as ultrashort pulse generators to extend ultrashort pulse reflectometry to high field tokamaks. Multiple barrier varactor devices; Use of monolithic NLTL to simplify moderate pulse reflectometry...

  • Sub-femtosecond X-ray pulse generation and measurement. Kienberger, R.; Hentschel, M.; Spielmann, C.; Reider, G.A.; Milosevic, N.; Heinzmann, U.; Drescher, M.; Krausz, F. // Applied Physics B: Lasers & Optics;2002 Supplement, Vol. 74 Issue 9, ps3 

    We report the generation and measurement of isolated soft-X-ray pulses (λ[sub X] = 14 nm) with a duration of τ[sub X] =650±150 attoseconds (as) by using few-cycle intense visible/near-infrared (λ[sub 0] = 750 nm) laser pulses. For the temporal characterization of the X-ray pulses, a...

  • Strong absorption, intense forward-Raman scattering and relativistic electrons driven by a short, high intensity laser pulse through moderately underdense plasmas. Rousseaux, C.; Rabec le Gloahec, M.; Baton, S. D.; Amiranoff, F.; Fuchs, J.; Gremillet, L.; Adam, J. C.; Héron, A.; Mora, P. // Physics of Plasmas;Oct2002, Vol. 9 Issue 10, p4261 

    The propagation of a short and intense laser pulse (1.057 µm, 350 fs, 10[sup 17] W/cm²-2 ×10[sup 19]W/cm²) through preformed undercritical plasmas (≈5%-40% of n[sub c]) has been experimentally investigated on the 100-TW laser facility at the Laboratoire pour l'Utilisation des...

  • High energy proton acceleration in interaction of short laser pulse with dense plasma target. Sentoku, Y.; Cowan, T. E.; Kemp, A.; Ruhl, H. // Physics of Plasmas;May2003, Vol. 10 Issue 5, p2009 

    The generation of high energy protons from the interaction of a short laser pulse with a dense plasma, accompanied by a preformed low density plasma, has been studied by particle-in-cell simulations. The proton acceleration toward the laser direction in the preformed plasma is characterized by a...

  • Effect of foil target thickness on fast proton generation driven by ultrashort-pulse laser. Badziak, J.; Woryna, E.; Parys, P.; Wołowski, J.; Platonov, K. Yu.; Vankov, A. B. // Journal of Applied Physics;4/15/2002, Vol. 91 Issue 8, p5504 

    The influence of the target foil thickness on the characteristics of a proton beam produced by the interaction of a 1-ps laser pulse with a plastic foil target at intensities near 10[sup 17] W/cm[sup 2] has been investigated. It is shown that, for maximizing the energies and/or the current of...

  • Millijoule energies, shortest ever pulses, and more.  // Nature Photonics;Jan2008, Vol. 2 Issue 1, p19 

    The article presents news briefs concerning the photonics industry. Researchers at the Friedrich-Schiller-University in Jena, Germany have developed an ultrashort-pulse fibre laser with a pulse energy of 1 millijoule and a repetition rate of 50 kHz. Tampere University of Technology researchers...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics