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Title: Studies of Ultrafast Femtosecond-Laser-Generated Strain Fields with Coherent X-rays

Abstract

In its 324 bunch-mode of operation, the Advanced Photon Source (APS) has opened new avenues of femtosecond-laser science and techniques. In this new mode, if one uses the tightly focused low-pulse energy (nJ), high repetition rate fs-laser Ti:sapphire oscillator (88 MHz) on beamline 7ID, every laser pulse and X-ray bunch can be overlapped and delayed with respect to each other, resulting in a high-repetition rate pump-probe experiment that uses all the APS X-ray bunches. This paper describes an example of how coherent X-ray experiments may be used to study laser-generated strain fields in semiconductors. With an oscillator beam focused to 6 {mu}m onto GaAs, we have observed coherent X-ray diffraction patterns with a high-resolution camera. We have developed two techniques to observe the strain field, a topographic technique and a coherent diffraction technique. The topographic technique is quite useful to achieve a coarse spatial overlap of the the laser and X-ray beams. The coherent X-ray technique allows one to push the alignment to a few microns. This paper focuses solely on the latter technique. This experiment may help to develop techniques that will be used at the future free electron laser sources, where coherent and pump-probe experiments can be donemore » simultaneously.« less

Authors:
; ; ;  [1]; ; ;  [2]
  1. X-ray Science Division, Argonne National Lab., Argonne, IL 60439 (United States)
  2. Department of Physics, University of Michigan, Ann Arbor MI 48109 (United States)
Publication Date:
OSTI Identifier:
21049240
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 879; Journal Issue: 1; Conference: 9. international conference on synchrotron radiation instrumentation, Daegu (Korea, Republic of), 28 May - 2 Jun 2006; Other Information: DOI: 10.1063/1.2436281; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ADVANCED PHOTON SOURCE; ALIGNMENT; CAMERAS; FREE ELECTRON LASERS; GALLIUM ARSENIDES; LASER RADIATION; MHZ RANGE; OPERATION; OSCILLATORS; PULSES; RESOLUTION; SAPPHIRE; SEMICONDUCTOR MATERIALS; STRAINS; X RADIATION; X-RAY DIFFRACTION

Citation Formats

Dufresne, Eric M., Adams, Bernhard, Landahl, Eric C., Khounsary, Ali M., Reis, David, Fritz, David M., and Lee, SooHeyong. Studies of Ultrafast Femtosecond-Laser-Generated Strain Fields with Coherent X-rays. United States: N. p., 2007. Web. doi:10.1063/1.2436281.
Dufresne, Eric M., Adams, Bernhard, Landahl, Eric C., Khounsary, Ali M., Reis, David, Fritz, David M., & Lee, SooHeyong. Studies of Ultrafast Femtosecond-Laser-Generated Strain Fields with Coherent X-rays. United States. doi:10.1063/1.2436281.
Dufresne, Eric M., Adams, Bernhard, Landahl, Eric C., Khounsary, Ali M., Reis, David, Fritz, David M., and Lee, SooHeyong. Fri . "Studies of Ultrafast Femtosecond-Laser-Generated Strain Fields with Coherent X-rays". United States. doi:10.1063/1.2436281.
@article{osti_21049240,
title = {Studies of Ultrafast Femtosecond-Laser-Generated Strain Fields with Coherent X-rays},
author = {Dufresne, Eric M. and Adams, Bernhard and Landahl, Eric C. and Khounsary, Ali M. and Reis, David and Fritz, David M. and Lee, SooHeyong},
abstractNote = {In its 324 bunch-mode of operation, the Advanced Photon Source (APS) has opened new avenues of femtosecond-laser science and techniques. In this new mode, if one uses the tightly focused low-pulse energy (nJ), high repetition rate fs-laser Ti:sapphire oscillator (88 MHz) on beamline 7ID, every laser pulse and X-ray bunch can be overlapped and delayed with respect to each other, resulting in a high-repetition rate pump-probe experiment that uses all the APS X-ray bunches. This paper describes an example of how coherent X-ray experiments may be used to study laser-generated strain fields in semiconductors. With an oscillator beam focused to 6 {mu}m onto GaAs, we have observed coherent X-ray diffraction patterns with a high-resolution camera. We have developed two techniques to observe the strain field, a topographic technique and a coherent diffraction technique. The topographic technique is quite useful to achieve a coarse spatial overlap of the the laser and X-ray beams. The coherent X-ray technique allows one to push the alignment to a few microns. This paper focuses solely on the latter technique. This experiment may help to develop techniques that will be used at the future free electron laser sources, where coherent and pump-probe experiments can be done simultaneously.},
doi = {10.1063/1.2436281},
journal = {AIP Conference Proceedings},
number = 1,
volume = 879,
place = {United States},
year = {Fri Jan 19 00:00:00 EST 2007},
month = {Fri Jan 19 00:00:00 EST 2007}
}
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  • Magnetic fields generated by a current flowing through a U-shaped coil connecting two copper foils were measured using ultrafast proton radiography. Two ∼1.25 kJ, 1-ns laser pulses propagated through laser entrance holes in the front foil and were focused to the back foil with an intensity of ∼3 × 10{sup 16 }W/cm{sup 2}. The intense laser-solid interaction induced a high voltage between the copper foils and generated a large current in the connecting coil. The proton data show ∼40–50 T magnetic fields at the center of the coil ∼3–4 ns after laser irradiation. The experiments provide significant insight for future target designs that aim tomore » develop a powerful source of external magnetic fields for various applications in high-energy-density science.« less
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  • Magnetic fields generated by a current flowing through a U-shaped coil connecting two copper foils were measured using ultrafast proton radiography. Two ~ 1.25 kJ, 1-ns laser pulses propagated through laser entrance holes in the front foil and were focused to the back foil with an intensity of ~ 3 x 10 16 W/cm 2. The intense laser-solid interaction induced a high voltage between the copper foils and generated a large current in the connecting coil. The proton data show ~ 40-50 T magnetic fields at the center of the coil ~ 3-4 ns after laser irradiation. In conclusion, themore » experiments provide significant insight for future target designs that aim to develop a powerful source of external magnetic fields for various applications in high-energy-density science.« less