TITLE

Fast electron temperature and conversion efficiency measurements in laser-irradiated foil targets using a bremsstrahlung x-ray detector

AUTHOR(S)
Westover, B.; Chen, C. D.; Patel, P. K.; Key, M. H.; McLean, H.; Stephens, R.; Beg, F. N.
PUB. DATE
June 2011
SOURCE
Physics of Plasmas;Jun2011, Vol. 18 Issue 6, p063101
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Measurements of fast electron temperature and conversion efficiencies using bremsstrahlung x-rays emitted from laser-produced, fast electrons are presented. Experiments were carried out using the Titan laser (150 J, 1.5 ps) at the Lawrence Livermore National Laboratory. The maximum intensity was 2 × 1020 W/cm2 on 250 μm thick silver foil targets. The emission of bremsstrahlung x-rays from the fast electrons in the target was measured using a filter-stack based detector. The conversion efficiency of laser energy into fast electrons and the electron temperature were studied as a function of incident laser energy. Several models of the electron divergence angle were investigated, and the effect of the assumed divergence angle on the inferred conversion efficiency was quantified. This allows for upper and lower bounds on the conversion efficiency to be established for a range of possible divergence angles. The value for upper bound is 60% (from a 75° divergence angle model) and for the lower bound is 25% (from a 0° divergence angle model).
ACCESSION #
62010255

 

Related Articles

  • Production of multi-MeV Bremsstrahlung x-ray sources by petawatt laser pulses on various targets. Compant La Fontaine, A.; Courtois, C.; Lefebvre, E. // Physics of Plasmas;Feb2012, Vol. 19 Issue 2, p023104 

    During the interaction of a high-intensity picosecond laser pulse with a plasma, a large amount of relativistic electrons are accelerated. If these electrons interact with a high-Z solid target, Bremsstrahlung photons are generated. This multi-MeV x-ray source may be used in various applications...

  • Progress in the shock-ignition inertial confinement fusion concept. Theobald, W.; Casner, A.; Nora, R.; Ribeyre, X.; Lafon, M.; Anderson, K. S.; Betti, R.; Craxton, R. S.; Delettrez, J. A.; Frenje, J. A.; Glebov, V. Yu.; Gotchev, O. V.; Hohenberger, M.; Hu, S. X.; Marshall, F. J.; McCrory, R. L.; Meyerhofer, D. D.; Perkins, L. J.; Sangster, T. C.; Schurtz, G. // EPJ Web of Conferences;2013, Issue 59, p1 

    Shock-ignition experiments with peak laser intensities of ~8 x 1015 W/cm² were performed. D2-filled plastic shells were compressed on a low adiabat by 40 of the 60 OMEGA beams. The remaining 20 beams were delayed and tightly focused onto the imploding shell to generate a strong shock. Up to...

  • Study of soft X-ray emission from Z-pinches with a complex atomic composition. Volkov, G. S.; Zaitsev, V. I.; Grabovski, E. V.; Fedulov, M. V.; Aleksandrov, V. V.; Lakhtyushko, N. I. // Plasma Physics Reports;Mar2010, Vol. 36 Issue 3, p191 

    Results are presented from experimental studies of Z-pinches produced by implosion of aluminum and tungsten cylindrical wire arrays in the Angara-5-1 facility. The electron temperature T e and density n e of the high-temperature pinch plasma have been determined by analyzing line emission from...

  • Soft x-ray images of the laser entrance hole of ignition hohlraums. Schneider, M. B.; Meezan, N. B.; Alvarez, S. S.; Alameda, J.; Baker, S.; Bell, P. M.; Bradley, D. K.; Callahan, D. A.; Celeste, J. R.; Dewald, E. L.; Dixit, S. N.; Döppner, T.; Eder, D. C.; Edwards, M. J.; Fernandez-Perea, M.; Gullikson, E.; Haugh, M. J.; Hau-Riege, S.; Hsing, W.; Izumi, N. // Review of Scientific Instruments;Oct2012, Vol. 83 Issue 10, p10E525 

    Hohlraums are employed at the national ignition facility to convert laser energy into a thermal x-radiation drive, which implodes a fusion capsule, thus compressing the fuel. The x-radiation drive is measured with a low spectral resolution, time-resolved x-ray spectrometer, which views the...

  • The x-ray observations of a CO2-laser-produced plasma. Meyer, J.; Popil, R. // Physics of Fluids (00319171);Jul85, Vol. 28 Issue 7, p2030 

    The x-ray observations of a CO[SUB2]-1aser-produced plasma are reported. An underdense plasma is produced by the interaction of intense ⩽; 10[SUP14] W/cm[SUP2] CO[SUB2] laser light with a laminar gas jet target. Initial observations at moderate < 10[SUP13] W/cm[SUB2] intensities and low...

  • An efficient method for simultaneous measurement of the integrated reflectivity of crystals in multiple orders of reflection using the bremsstrahlung continuum from an x-ray tube and comparison of experimental results for mica with theoretical calculations Lee, S. G.; J. G. Bak, S. G.; Jung, Y. S.; Bitter, M.; Hill, K. W.; Hölzer, G.; Wenhrhan, O.; Förster, E. // Review of Scientific Instruments;Dec2003, Vol. 74 Issue 12, p5046 

    This article describes an efficient method for the simultaneous measurement of the integrated reflectivity of a crystal in multiple orders of reflection at a predefined Bragg angle by using the bremsstrahlung continuum from an x-ray tube in combination with an energy-sensitive detector. The...

  • High-efficiency high-power QCW diode-side-pumped zigzag Nd:YAG ceramic slab laser. Chen, Y.; Liu, W.; Bo, Y.; Jiang, B.; Xu, J.; Li, J.; Xu, Y.; Pan, Y.; Feng, X.; Guo, Y.; Shen, Y.; Yang, F.; Yuan, L.; Yuan, H.; Peng, Q.; Cui, D.; Xu, Z. // Applied Physics B: Lasers & Optics;Apr2013, Vol. 111 Issue 1, p111 

    A high-efficiency high-power diode-side-pumped quasi-continuous wave (QCW) Nd:YAG ceramic slab laser using zigzag optical path was demonstrated. With an integrating sphere technique, the scattering and absorption coefficient of the ceramic slab were measured to be 0.0024 and 0.0016 cm at 1,064...

  • Efficient and wavelength-tunable anti-Stokes frequency conversion with good beam quality in the fundamental mode of photonic crystal fiber. Yuan, J.-H.; Sang, X.-Z.; Yu, C.-X.; Rao, L.; Han, Y.; Zhou, G.-Y.; Li, S.-G.; Hou, L.-T. // Applied Physics B: Lasers & Optics;Dec2011, Vol. 105 Issue 4, p685 

    Using the photonic crystal fiber (PCF) with the zero dispersion wavelength of 848 nm for the fundamental mode, the efficient anti-Stokes signal generations from 645 to 543 nm are realized by pumping in the normal dispersion region. When the pump average power increases from 200 to 500 mW, the...

  • Start-phase ionization dynamics in the laser plasma at low gas target densities. Belik, V. P.; Demidov, R. A.; Kalmykov, S. G.; Mozharov, A. M.; Petrenko, M. V.; Sasin, M. E. // Technical Physics;Dec2013, Vol. 58 Issue 12, p1783 

    In Xe laser-produced-plasma sources of short-wave radiation, the laser-energy-to-EUV conversion efficiency (CE) proves substantially less than theoretical expectations. In the present work, a calculated estimate has been made which indicates that a long period of the primary ionization, lasting...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

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

Try another library?
Sign out of this library

Other Topics