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Title: Ultrafast pulse radiolysis using a terawatt laser wakefield accelerator.

Abstract

No abstract prepared.

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
914835
Report Number(s):
ANL/CHM/JA-57221
Journal ID: ISSN 0021-8979; JAPIAU; TRN: US0803390
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Appl. Phys.; Journal Volume: 101; Journal Issue: Mar. 1, 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
43 PARTICLE ACCELERATORS; LASERS; RADIOLYSIS; WAKEFIELD ACCELERATORS

Citation Formats

Oulianov, D. A., Crowell, R. A., Gosztola, D. J., Shkrob, I. A., Korovyanko, O. J., Rey-de-Castro, R. C., and Chemistry. Ultrafast pulse radiolysis using a terawatt laser wakefield accelerator.. United States: N. p., 2007. Web. doi:10.1063/1.2696204.
Oulianov, D. A., Crowell, R. A., Gosztola, D. J., Shkrob, I. A., Korovyanko, O. J., Rey-de-Castro, R. C., & Chemistry. Ultrafast pulse radiolysis using a terawatt laser wakefield accelerator.. United States. doi:10.1063/1.2696204.
Oulianov, D. A., Crowell, R. A., Gosztola, D. J., Shkrob, I. A., Korovyanko, O. J., Rey-de-Castro, R. C., and Chemistry. Thu . "Ultrafast pulse radiolysis using a terawatt laser wakefield accelerator.". United States. doi:10.1063/1.2696204.
@article{osti_914835,
title = {Ultrafast pulse radiolysis using a terawatt laser wakefield accelerator.},
author = {Oulianov, D. A. and Crowell, R. A. and Gosztola, D. J. and Shkrob, I. A. and Korovyanko, O. J. and Rey-de-Castro, R. C. and Chemistry},
abstractNote = {No abstract prepared.},
doi = {10.1063/1.2696204},
journal = {J. Appl. Phys.},
number = Mar. 1, 2007,
volume = 101,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • We report ultrafast pulse radiolysis transient absorption (TA) spectroscopy measurements from the Terawatt Ultrafast High Field Facility (TUHFF) at Argonne National Laboratory. TUHFF houses a 20 TW Ti:sapphire laser system that generates 2.5 nC subpicosecond pulses of multi-mega-electron-volt electrons at 10 Hz using laser wakefield acceleration. The system has been specifically optimized for kinetic TA measurements in a pump-probe fashion. This requires averaging over many shots which necessitates stable, reliable generation of electron pulses. The latter were used to generate excess electrons in pulse radiolysis of liquid water and concentrated solutions of perchloric acid. The hydronium ions in the acidicmore » solutions react with the hydrated electrons resulting in the rapid decay of the transient absorbance at 800 nm on the picosecond time scale. Normalization of the TA signal leads to an improvement in the signal to noise ratio by a factor of 5 to 6. Due the pointing instability of the laser this improvement was limited to a 5 to 10 min acquisition period, requiring periodic recalibration and realignment. Time resolution, defined by the rise time of TA signal from hydrated electron in pulse radiolysis of liquid water, of a few picoseconds, has been demonstrated. The current time resolution is determined primarily by the physical dimensions of the sample and the detection sensitivity. Subpicosecond time resolution can be achieved by using thinner samples, more sensitive detection techniques, and improved electron beam quality.« less
  • A laser based electron generator is shown, for the first time, to produce sufficient charge to conduct time resolved investigations of radiation induced chemical events. Electron pulses generated by focusing terawatt laser pulses into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced by the ionizing electron pulses is monitored with 0.3 {mu}s time resolution. Hydrated electron concentrations as high as 22 {mu}M were generated. The results show that terawatt lasers offer both an alternative to linear accelerators and a means to achieve subpicosecond time resolution for pulse radiolysis studies.
  • A laser based electron generator is shown, for the first time, to produce sufficient charge to conduct time resolved investigations of radiation induced chemical events. Electron pulses generated by focussing terawatt laser pulses into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced by the ionizing electron pulses is monitored with 0.3 {mu}s time resolution. Hydrated electron concentrations as high as 22 {mu}M were generated. The results show that terawatt lasers offer both an alternative to linear accelerators and a means to achieve subpicosecond time resolution for pulse radiolysis studies. (c)more » 2000 American Institute of Physics.« less
  • We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.
  • The development of new laser systems at the 10 Petawatt range will push laser wakefield accelerators to novel regimes, for which theoretical scalings predict the possibility to accelerate electron bunches up to tens of GeVs in meter-scale plasmas. Numerical simulations will play a crucial role in testing, probing, and optimizing the physical parameters and the setup of future experiments. Fully kinetic simulations are computationally very demanding, pushing the limits of today's supercomputers. In this paper, the recent developments in the OSIRIS framework [R. A. Fonseca et al., Lect. Notes Comput. Sci. 2331, 342 (2002)] are described, in particular the boostedmore » frame scheme, which leads to a dramatic change in the computational resources required to model laser wakefield accelerators. Results from one-to-one modeling of the next generation of laser systems are discussed, including the confirmation of electron bunch acceleration to the energy frontier.« less