skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Benchmarking transition energies and emission strengths for X-ray astrophysics with measurements at the Livermore EBITs

Abstract

K-shell transitions in astrophysically abundant metals and L-shell transitions in Fe group elements show characteristic signatures in the soft X-ray spectrum in the energy range 0.1–10 keV. These signatures have great diagnostic value for plasma parameters such as electron and ion temperatures and densities, and can thus help understand the physics controlling the energetic processes in astrophysical sources. This diagnostic power increases with advances in spectral resolution and effective area of the employed X-ray observatories. However, to make optimal use of the diagnostic potential – whether through global spectral modeling or through diagnostics from local modeling of individual lines – the underlying atomic physics has to be complete and well known. With the next generation of soft X-ray observatories featuring micro-calorimeters such as the SXS on Astro- H/Hitomi and the X-IFU on Athena, broadband high-resolution spectroscopy with large effective area will become more commonly available in the next decade. With these spectrometers, the accuracy of the plasma parameters derived from spectral modeling will be limited by the uncertainty of the reference atomic data rather than by instrumental factors, as is sometimes already the case for the high-resolution grating observations with Chandra-HETG and XMM-Newton-RGS. To take full advantage of the measuredmore » spectra, assessment of the accuracy of and improvements to the available atomic reference data are therefore important. Dedicated measurements in the laboratory are essential to benchmark the theoretical calculations providing the bulk of the reference data used in astrophysics. Experiments at the Lawrence Livermore National Laboratory electron beam ion traps (EBIT-I and SuperEBIT) have a long history of providing this service. In this work, I present new measurements of transition energies and absolute electron impact excitation cross sections geared towards currently open atomic physics data needs.« less

Authors:
 [1]
  1. Friedrich Alexander Univ., Erlangen (Germany)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1349014
Report Number(s):
LLNL-TH-727717
DOE Contract Number:  
AC52-07NA27344
Resource Type:
Thesis/Dissertation
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 79 ASTRONOMY AND ASTROPHYSICS; 70 PLASMA PHYSICS AND FUSION

Citation Formats

Hell, Natalie. Benchmarking transition energies and emission strengths for X-ray astrophysics with measurements at the Livermore EBITs. United States: N. p., 2017. Web. doi:10.2172/1349014.
Hell, Natalie. Benchmarking transition energies and emission strengths for X-ray astrophysics with measurements at the Livermore EBITs. United States. doi:10.2172/1349014.
Hell, Natalie. Wed . "Benchmarking transition energies and emission strengths for X-ray astrophysics with measurements at the Livermore EBITs". United States. doi:10.2172/1349014. https://www.osti.gov/servlets/purl/1349014.
@article{osti_1349014,
title = {Benchmarking transition energies and emission strengths for X-ray astrophysics with measurements at the Livermore EBITs},
author = {Hell, Natalie},
abstractNote = {K-shell transitions in astrophysically abundant metals and L-shell transitions in Fe group elements show characteristic signatures in the soft X-ray spectrum in the energy range 0.1–10 keV. These signatures have great diagnostic value for plasma parameters such as electron and ion temperatures and densities, and can thus help understand the physics controlling the energetic processes in astrophysical sources. This diagnostic power increases with advances in spectral resolution and effective area of the employed X-ray observatories. However, to make optimal use of the diagnostic potential – whether through global spectral modeling or through diagnostics from local modeling of individual lines – the underlying atomic physics has to be complete and well known. With the next generation of soft X-ray observatories featuring micro-calorimeters such as the SXS on Astro- H/Hitomi and the X-IFU on Athena, broadband high-resolution spectroscopy with large effective area will become more commonly available in the next decade. With these spectrometers, the accuracy of the plasma parameters derived from spectral modeling will be limited by the uncertainty of the reference atomic data rather than by instrumental factors, as is sometimes already the case for the high-resolution grating observations with Chandra-HETG and XMM-Newton-RGS. To take full advantage of the measured spectra, assessment of the accuracy of and improvements to the available atomic reference data are therefore important. Dedicated measurements in the laboratory are essential to benchmark the theoretical calculations providing the bulk of the reference data used in astrophysics. Experiments at the Lawrence Livermore National Laboratory electron beam ion traps (EBIT-I and SuperEBIT) have a long history of providing this service. In this work, I present new measurements of transition energies and absolute electron impact excitation cross sections geared towards currently open atomic physics data needs.},
doi = {10.2172/1349014},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2017},
month = {3}
}

Thesis/Dissertation:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this thesis or dissertation.

Save / Share: