Indirect monitoring shot-to-shot shock waves strength reproducibility during pump–probe experiments

Journal Article · Thu Jul 21 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4958796· OSTI ID:22597830

Faenov, A. Ya. ^[1]; Ozaki, N.; Habara, H.; Tanaka, K. A.; Kodama, R. ^[2]; Hartley, N. J.; Matsuoka, T. ^[3]; Albertazzi, B.; Matsuyama, S.; Yamauchi, K.; Ochante, R. ^[2]; Takahashi, K.; Sueda, K. ^[4]; Tange, Y. ^[5]; Sakata, O. ^[6]; Sekine, T.; Sato, T.; Umeda, Y. ^[7]; Inubushi, Y. ^[5]; others, and

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1. Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation)
2. Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 Japan (Japan)
3. Institute for Academic Initiatives, Osaka University, Suita, Osaka 565-0871 (Japan)
4. Photon Pioneers Center, Osaka University, Suita, Osaka 565-0871 Japan (Japan)
5. Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan)
6. Synchrotron X-ray Station at SPring-8, NIMS, Sayo, Hyogo 679-5148 (Japan)
7. Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)

We present an indirect method of estimating the strength of a shock wave, allowing on line monitoring of its reproducibility in each laser shot. This method is based on a shot-to-shot measurement of the X-ray emission from the ablated plasma by a high resolution, spatially resolved focusing spectrometer. An optical pump laser with energy of 1.0 J and pulse duration of ∼660 ps was used to irradiate solid targets or foils with various thicknesses containing Oxygen, Aluminum, Iron, and Tantalum. The high sensitivity and resolving power of the X-ray spectrometer allowed spectra to be obtained on each laser shot and to control fluctuations of the spectral intensity emitted by different plasmas with an accuracy of ∼2%, implying an accuracy in the derived electron plasma temperature of 5%–10% in pump–probe high energy density science experiments. At nano- and sub-nanosecond duration of laser pulse with relatively low laser intensities and ratio Z/A ∼ 0.5, the electron temperature follows T{sub e} ∼ I{sub las}{sup 2/3}. Thus, measurements of the electron plasma temperature allow indirect estimation of the laser flux on the target and control its shot-to-shot fluctuation. Knowing the laser flux intensity and its fluctuation gives us the possibility of monitoring shot-to-shot reproducibility of shock wave strength generation with high accuracy.

• OSTI ID: 22597830
• Journal Information: Journal of Applied Physics, Vol. 120, Issue 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACCURACY
ALUMINIUM
ELECTRON TEMPERATURE
ELECTRONS
ENERGY DENSITY
FLUCTUATIONS
ION TEMPERATURE
IRON
LASERS
MONITORING
OPTICAL PUMPING
OXYGEN
PLASMA
RESOLUTION
SENSITIVITY
SHOCK WAVES
TANTALUM
THICKNESS
X RADIATION
X-RAY SPECTROMETERS