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Background measurement methods for opacity experiments conducted at the Z facility

Review of Scientific Instruments

Dunham, Gregory S.; Nagayama, Taisuke N.; Bailey, James E.; Loisel, Guillaume P.

Laboratory experiments typically test opacity models by measuring spectrally resolved transmission of a sample using bright backlight radiation. A potential problem is that any unaccounted background signal contaminating the spectrum will artificially reduce the inferred opacity. Methods developed to measure background signals in opacity experiments at the Sandia Z facility are discussed. Preliminary measurements indicate that backgrounds are 9%–11% of the backlight signal at wavelengths less than 10 Å. Background is thus a relatively modest correction for all Z opacity data published to date. Future work will determine how important background is at longer wavelengths.

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Opacity data for stellar models and its uncertainties

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Opacity data for stellar models and its uncertainties

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Opacity data for stellar models and its uncertainties

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Ride-along data LOS 130, 170 & LO330 shots z3139, 3140 and 3141

Loisel, Guillaume P.

Each instrument records the x-ray emission from the Z-pinch dynamic hohlraum (ZPDH); LOS 130 TIXTLs instruments record the absorption of the pinch backlighter through an expanding NaF/Mg foil; LOS 170 MLM instruments record monochromatic images at 276 and 528 eV energies near and before ZPDH stagnation time; LOS 330 TREX 6A & B: recoded time resolved absorption spectra from a radiatively heated Ne gas.

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The Differential Absorption Hard X-Ray Spectrometer at the Z Facility

IEEE Transactions on Plasma Science

Bell, Kate S.; Coverdale, Christine A.; Ampleford, David A.; Bailey, James E.; Loisel, Guillaume P.; Harper-Slaboszewicz, V.H.; Schwarz, Jens S.; Moy, Kenneth

The differential absorption hard X-ray (DAHX) spectrometer is a diagnostic developed to measure time-resolved radiation between 60 keV and 2 MeV at the Z Facility. It consists of an array of seven Si PIN diodes in a tungsten housing that provides collimation and coarse spectral resolution through differential filters. DAHX is a revitalization of the hard X-ray spectrometer that was fielded on Z prior to refurbishment in 2006. DAHX has been tailored to the present radiation environment in Z to provide information on the power, spectral shape, and time profile of the hard emission by plasma radiation sources driven by the Z machine.

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Measuring the radiative properties of astrophysical matter using the Z x-ray source

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Brief overview of opacity measurements for stellar interior conditions

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Systematic measurements of opacity dependence on temperature density and atomic number at stellar interior conditions

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Systematic search for spherical crystal X-ray microscopes matching 1-25 keV spectral line sources

Review of Scientific Instruments

Schollmeier, Marius; Loisel, Guillaume P.

Spherical-crystal microscopes are used as high-resolution imaging devices for monochromatic x-ray radiography or for imaging the source itself. Crystals and Miller indices (hkl) have to be matched such that the resulting lattice spacing d is close to half the spectral wavelength used for imaging, to fulfill the Bragg equation with a Bragg angle near 90∘ which reduces astigmatism. Only a few suitable crystal and spectral-line combinations have been identified for applications in the literature, suggesting that x-ray imaging using spherical crystals is constrained to a few chance matches. In this article, after performing a systematic, automated search over more than 9 × 106 possible combinations for x-ray energies between 1 and 25 keV, for six crystals with arbitrary Miller-index combinations hkl between 0 and 20, we show that a matching, efficient crystal and spectral-line pair can be found for almost every Heα or Kα x-ray source for the elements Ne to Sn. Using the data presented here it should be possible to find a suitable imaging combination using an x-ray source that is specifically selected for a particular purpose, instead of relying on the limited number of existing crystal imaging systems that have been identified to date.

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Systematic measurements of opacity dependence on temperature density and atomic number at stellar interior conditions

Nagayama, Taisuke N.; Bailey, James E.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; MacFarlane, J.J.M.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pradham, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Systematic measurements of opacity dependence on temperature density and atomic number at stellar interior conditions

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Measuring the radiative properties of astrophysical matter using the Z x-ray source

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Iron Opacity Measurements at Solar Interior Temperatures

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Non-thermal x-ray emission from wire array z-pinches

Ampleford, David A.; Hansen, Stephanie B.; Jennings, Christopher A.; Webb, Timothy J.; Harper-Slaboszewicz, V.H.; Loisel, Guillaume P.; Flanagan, Timothy M.; Bell, Kate S.; Jones, Brent M.; Rochau, G.A.; Chittenden, Jeremy P.; Sherlock, Mark S.; Appelbe, Brian A.; Giuliani, John G.; Ouart, Nicholas O.; Seely, John S.; McPherson, Leroy A.

We report on experiments demonstrating the transition from thermally-dominated K-shell line emission to non-thermal, hot-electron-driven inner-shell emission for z pinch plasmas on the Z machine. While x-ray yields from thermal K-shell emission decrease rapidly with increasing atomic number Z, we find that non-thermal emission persists with favorable Z scaling, dominating over thermal emission for Z=42 and higher (hn ≥ 17keV). Initial experiments with Mo (Z=42) and Ag (Z=47) have produced kJ-level emission in the 17-keV and 22-keV Kα lines respectively. We will discuss the electron beam properties that could excite these non - thermal lines. We also report on experiments that have attempted to control non - thermal K - shell line emission by modifying the wire array or load hardware setup.

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ZAPP shot summary

Loisel, Guillaume P.

This was the second Z Astrophysical Plasma Properties (ZAPP) fundamental science shot series of 2015. ZAPP experiments measure fundamental properties of atoms in plasmas to solve the following important astrophysical puzzles: Why can’t we accurately model the opacity of Fe at the convection zone boundary in the Sun? How accurate are the photoionization models used to interpret data from xray satellite observations? and Why doesn’t spectral fitting provide the correct properties for White Dwarfs?

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Measuring the opacity of stellar interior matter in terrestrial laboratories

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Iron Opacity Measurements at Solar Interior Temperatures

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; Macfarlane, Joseph J.; Mancini, Roberto C.; Nahar, S.N.N.; Orban, C.O.; Pain, J.-C.P.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

Measurements of iron plasma opacity at solar interior temperatures

Nature

Bailey, James E.; Nagayama, Taisuke N.; Loisel, Guillaume P.; Rochau, G.A.; Blancard, C.B.; Colgan, J.C.; Cosse, Ph.C.; Faussurier, G.F.; Fontes, C.J.F.; Gilleron, F.G.; Golovkin, I.G.; Hansen, Stephanie B.; Iglesias, C.A.I.; Kilcrease, D.P.K.; MacFarlane, J.J.M.; Mancini, R.C.M.; Orban, C.O.; Pain, J.-CP.; Pradhan, A.K.P.; Sherrill, M.S.; Wilson, B.G.W.

Abstract not provided.

97 Results
97 Results