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Döppner T, Bethkenhagen M, Kraus D, Neumayer P, Chapman DA, Bachmann B, Baggott RA, Böhme MP, Divol L, Falcone RW, Fletcher LB, Landen OL, MacDonald MJ, Saunders AM, Schörner M, Sterne PA, Vorberger J, Witte BBL, Yi A, Redmer R, Glenzer SH, Gericke DO. Observing the onset of pressure-driven K-shell delocalization. Nature 2023:10.1038/s41586-023-05996-8. [PMID: 37225995 DOI: 10.1038/s41586-023-05996-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 03/22/2023] [Indexed: 05/26/2023]
Abstract
The gravitational pressure in many astrophysical objects exceeds one gigabar (one billion atmospheres)1-3, creating extreme conditions where the distance between nuclei approaches the size of the K shell. This close proximity modifies these tightly bound states and, above a certain pressure, drives them into a delocalized state4. Both processes substantially affect the equation of state and radiation transport and, therefore, the structure and evolution of these objects. Still, our understanding of this transition is far from satisfactory and experimental data are sparse. Here we report on experiments that create and diagnose matter at pressures exceeding three gigabars at the National Ignition Facility5 where 184 laser beams imploded a beryllium shell. Bright X-ray flashes enable precision radiography and X-ray Thomson scattering that reveal both the macroscopic conditions and the microscopic states. The data show clear signs of quantum-degenerate electrons in states reaching 30 times compression, and a temperature of around two million kelvins. At the most extreme conditions, we observe strongly reduced elastic scattering, which mainly originates from K-shell electrons. We attribute this reduction to the onset of delocalization of the remaining K-shell electron. With this interpretation, the ion charge inferred from the scattering data agrees well with ab initio simulations, but it is significantly higher than widely used analytical models predict6.
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Affiliation(s)
- T Döppner
- Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - M Bethkenhagen
- Institute of Physics, University of Rostock, Rostock, Germany
- École Normale Supérieure de Lyon, LGLTPE, CNRS UMR 5276, Lyon, France
| | - D Kraus
- Institute of Physics, University of Rostock, Rostock, Germany
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - P Neumayer
- GSI Helmholtz-Zentrum für Schwerionenforschung, Darmstadt, Germany
| | | | - B Bachmann
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - R A Baggott
- The John Adams Institute for Accelerator Science, Imperial College London, London, UK
| | - M P Böhme
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Center for Advanced Systems Understanding (CASUS), Görlitz, Germany
- Technische Universität Dresden, Dresden, Germany
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - R W Falcone
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
| | - L B Fletcher
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - M J MacDonald
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - A M Saunders
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - M Schörner
- Institute of Physics, University of Rostock, Rostock, Germany
| | - P A Sterne
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - J Vorberger
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - B B L Witte
- Institute of Physics, University of Rostock, Rostock, Germany
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - A Yi
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - R Redmer
- Institute of Physics, University of Rostock, Rostock, Germany
| | - S H Glenzer
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D O Gericke
- Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry, UK
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