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Title: Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft X-ray range

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
899387
Report Number(s):
UCRL-JRNL-220096
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review E, vol. 74, N/A, July 24, 2006, pp. 016404
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 70 PLASMA PHYSICS AND FUSION

Citation Formats

Filevich, J, Grava, J, Purvis, M, Marconi, M C, Rocca, J J, Nilsen, J, Dunn, J, and Johnson, W R. Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft X-ray range. United States: N. p., 2006. Web. doi:10.1103/PhysRevE.74.016404.
Filevich, J, Grava, J, Purvis, M, Marconi, M C, Rocca, J J, Nilsen, J, Dunn, J, & Johnson, W R. Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft X-ray range. United States. doi:10.1103/PhysRevE.74.016404.
Filevich, J, Grava, J, Purvis, M, Marconi, M C, Rocca, J J, Nilsen, J, Dunn, J, and Johnson, W R. Thu . "Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft X-ray range". United States. doi:10.1103/PhysRevE.74.016404. https://www.osti.gov/servlets/purl/899387.
@article{osti_899387,
title = {Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft X-ray range},
author = {Filevich, J and Grava, J and Purvis, M and Marconi, M C and Rocca, J J and Nilsen, J and Dunn, J and Johnson, W R},
abstractNote = {},
doi = {10.1103/PhysRevE.74.016404},
journal = {Physical Review E, vol. 74, N/A, July 24, 2006, pp. 016404},
number = ,
volume = ,
place = {United States},
year = {Thu Mar 23 00:00:00 EST 2006},
month = {Thu Mar 23 00:00:00 EST 2006}
}
  • We present the calculated prediction and the experimental confirmation that doubly ionized Ag and Sn plasmas can have an index of refraction greater than one for soft x-ray wavelengths. Interferometry experiments conducted using a capillary discharge soft x-ray laser operating at a wavelength of 46.9 nm (26.44 eV) confirm that in few times ionized laser-created plasmas of these elements the anomalous dispersion from bound electrons can dominate the free electron contribution, making the index of refraction greater than one. The results confirm that bound electrons can strongly influence the index of refraction of numerous plasmas over a broad range ofmore » soft x-ray wavelengths confirming recent observations. The understanding of index of refraction at short wavelengths will become even more essential during the next decade as x-ray free electron lasers will become available to probe a wider variety of plasmas at higher densities and shorter wavelengths.« less
  • We present clear experimental evidence showing that the contribution of bound electrons can dominate the index of refraction of laser created plasmas at soft x-ray wavelengths. We report anomalous fringe shifts in soft x-ray laser interferograms of Al laser-created plasmas. The comparison of measured and simulated interferograms show that this results from the dominant contribution of low charge ions to the index of refraction. This usually neglected bound electron contribution can a.ect the propagation of soft x-ray radiation in plasmas and the interferometric diagnostics of plasmas for many elements.
  • Over the last decade, X-ray lasers in the wavelength range14 - 47 nm have been used to do interferometry of plasmas. Just as for optical interferometry of plasmas, the experimental analysis assumed that the index of refraction is due only to the free electrons. This makes the index of refraction less then one. Recent experiments in Al plasmas have observed fringe lines bend the wrong way as though the electron density is negative. We show how the bound electrons can dominate the index of refraction in many plasmas and make the index greater than one or enhance the index suchmore » that one would greatly overestimate the density of the plasma using interferometry.« less
  • Coherent radiation from undulator beamlines has been used to directly measure the real and imaginary parts of the index of refraction of several materials at both extreme-ultraviolet and soft-x-ray wavelengths. Using the XOR interferometer, we measure the refractive indices of silicon and ruthenium, essential materials for extreme-ultraviolet lithography. Both materials are tested at wavelength (13.4 nm) and across silicon's L2(99.8 eV) and L3(99.2 eV) absorption edges. We further extend this direct phase measurement method into the soft-x-ray region, where measurements of chromium and vanadium are performed around their L3absorption edges at 574.1 and 512.1 eV, respectively. These are the firstmore » direct measurements, to our knowledge, of the real part of the index of refraction made in the soft-x-ray region.« less
  • No abstract prepared.