Ultrafast electron kinetics in short pulse laser-driven dense hydrogen

Journal Article · Fri Sep 25 00:00:00 EDT 2015 · Journal of Physics. B, Atomic, Molecular and Optical Physics

DOI:https://doi.org/10.1088/0953-4075/48/22/224004· OSTI ID:1249381

Zastrau, U. ^[1]; Sperling, P. ^[2]; Fortmann-Grote, C. ^[3]; Becker, A. ^[4]; Bornath, T. ^[4]; Bredow, R. ^[4]; Doppner, T. ^[5]; Fennel, T. ^[4]; Fletcher, L. B. ^[6]; Forster, E. ^[7]; Gode, S. ^[6]; Gregori, G. ^[8]; Harmand, M. ^[9]; Hilbert, V. ^[10]; Laarmann, T. ^[11]; Lee, H. J. ^[6]; Ma, T. ^[5]; Meiwes-Broer, K. H. ^[4]; Mithen, J. P. ^[8]; Murphy, C. D. ^[12] ; Nakatsutsumi, M. ^[13]; Neumayer, P. ^[14]; Przystawik, A. ^[15]; Skruszewicz, S. ^[4]; Tiggesbaumker, J. ^[4]; Toleikis, S. ^[15]; White, T. G. ^[16]; Glenzer, S. H. ^[6]; Redmer, R. ^[4]; Tschentscher, T. ^[13]

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1. European XFEL, Hamburg (Germany); Friedrich-Schiller-Univ., Jena (Germany)
2. SLAC National Accelerator Lab., Menlo Park, CA (United States); Univ. Rostock, Rostock (Germany)
3. Quantum Wise A/S, Copenhagen (Denmark)
4. Univ. Rostock, Rostock (Germany)
5. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
6. SLAC National Accelerator Lab., Menlo Park, CA (United States)
7. Friedrich-Schiller-Univ., Jena (Germany); Helmholtz-Institut Jena, Jena (Germany)
8. Univ. of Oxford, Oxford (United Kingdom)
9. Institut de mineralogie, Paris (France); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
10. Friedrich-Schiller-Univ., Jena (Germany)
11. Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging CUI, Hamburg (Germany)
12. Univ. of Edinburgh, Edinburgh (United Kingdom)
13. European XFEL, Hamburg (Germany)
14. Extreme Matter Institute, GSI Helmholtzzentrum fur Schwerionenforschung, Darmstadt (Germany)
15. Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
16. Imperial College, London (United Kingdom)

Dense cryogenic hydrogen is heated by intense femtosecond infrared laser pulses at intensities of 10¹⁵ – 10¹⁶W cm^–2. Three-dimensional particle-in-cell (PIC) simulations predict that this heating is limited to the skin depth, causing an inhomogeneously heated outer shell with a cold core and two prominent temperatures of about $25$ and $$40\;\mathrm{eV}$$ for simulated delay times up to $$+70\;\mathrm{fs}$$ after the laser pulse maximum. Experimentally, the time-integrated emitted bremsstrahlung in the spectral range of 8–18 nm was corrected for the wavelength-dependent instrument efficiency. The resulting spectrum cannot be fit with a single temperature bremsstrahlung model, and the best fit is obtained using two temperatures of about 13 and $$30\;$$eV. The lower temperatures in the experiment can be explained by missing energy-loss channels in the simulations, as well as the inclusion of hot, non-Maxwellian electrons in the temperature calculation. Furthermore, we resolved the time-scale for laser-heating of hydrogen, and PIC results for laser–matter interaction were successfully tested against the experiment data.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-76SF00515; AC52-07NA27344
• OSTI ID: 1249381
• Alternate ID(s): OSTI ID: 1260499
• Report Number(s): SLAC-PUB-16138; LLNL-JRNL-686307
• Journal Information: Journal of Physics. B, Atomic, Molecular and Optical Physics, Vol. 48, Issue 22; ISSN 0953-4075
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
43 PARTICLE ACCELERATORS
PHYS
OPTICS
electron collision
emission
absorption
scattering of electromagnetic radiation
plasma production
heating by laser beams
70 PLASMA PHYSICS AND FUSION