Dynamic optical spectroscopy and pyrometry of static targets under optical and x-ray laser heating at the European XFEL
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2023-08-02 |
| Journal | Journal of Applied Physics |
| Authors | Orianna B. Ball, Clemens Prescher, Karen Appel, Carsten Baehtz, M. Baron |
| Institutions | University of Rostock, Sorbonne UniversitƩ |
| Citations | 8 |
Abstract
Section titled āAbstractāExperiments accessing extreme conditions at x-ray free electron lasers (XFELs) involve rapidly evolving conditions of temperature. Here, we report time-resolved, direct measurements of temperature using spectral streaked optical pyrometry of x-ray and optical laser-heated states at the High Energy Density instrument of the European XFEL. This collection of typical experiments, coupled with numerical models, outlines the reliability, precision, and meaning of time dependent temperature measurements using optical emission at XFEL sources. Dynamic temperatures above 1500 K are measured continuously from spectrally- and temporally-resolved thermal emission at 450-850 nm, with time resolution down to 10-100 ns for 1-200 μs streak camera windows, using single shot and integrated modes. Targets include zero-pressure foils free-standing in air and in vacuo, and high-pressure samples compressed in diamond anvil cell multi-layer targets. Radiation sources used are 20-fs hard x-ray laser pulses at 17.8 keV, in single pulses or 2.26 MHz pulse trains of up to 30 pulses, and 250-ns infrared laser single pulses. A range of further possibilities for optical measurements of visible light in x-ray laser experiments using streak optical spectroscopy are also explored, including for the study of x-ray induced optical fluorescence, which often appears as background in thermal radiation measurements. We establish several scenarios where combined emissions from multiple sources are observed and discuss their interpretation. Challenges posed by using x-ray lasers as non-invasive probes of the sample state are addressed.
Tech Support
Section titled āTech SupportāOriginal Source
Section titled āOriginal SourceāReferences
Section titled āReferencesā- 1999 - Interiors of giant planets inside and outside the solar system [Crossref]
- 2004 - The physics basis for ignition using indirect-drive targets on the national ignition facility [Crossref]
- 2021 - First-principles equation of state database for warm dense matter computation [Crossref]
- 2020 - Carbon ionization at gigabar pressures: An ab initio perspective on astrophysical high-density plasmas [Crossref]
- 2020 - Determination of the melting curve of gold up to 110āGPa [Crossref]
- 2013 - Mapping temperatures and temperature gradients during flash heating in a diamond-anvil cell [Crossref]
- 2010 - High melting points of tantalum in a laser-heated diamond anvil cell [Crossref]
- 2014 - Strategies for in situ laser heating in the diamond anvil cell at an X-ray diffraction beamline [Crossref]