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1. X-ray sources for in situ wavelength calibration of x-ray imaging crystal spectrometers.

Author

Shah, K., Delgado-Aparicio, L., Kraus, B. F., Ono, M., Gao, L., Umbach, B., Perkins, L., Pablant, N., Hill, K. W., Bitter, M., Teall, S., Drake, R., and Schmidt, G.

Subjects
DOPPLER effect, X-ray spectra, PLASMA flow, X-ray imaging, X-ray tubes
Abstract

X-ray sources for a range of wavelengths are being considered for in situ calibration of X-ray Imaging Crystal Spectrometers (XICSs) and for monitoring line shifts due to changes in the crystal temperature, which can vary during experimental operation over a day [A. Ince-Cushman et al., Rev. Sci. Instrum. 79, 10E302 (2008), L. Delgado-Aparicio et al., Plasma Phys. Control. Fusion 55, 125011 (2013)]. Such crystal temperature dependent shifts, if not accounted for, could be erroneously interpreted as Doppler shifts leading to errors in plasma flow-velocity measurements. The x-ray sources encompass characteristic x-ray lines falling within the wavelength range of 0.9–4.0 Å, relevant for the XICSs on present and future fusion devices. Several technological challenges associated with the development of x-ray sources for in situ calibration are identified and are being addressed in the design of multiple x-ray tubes, which will be installed inside the spectrometer housing of the XICS for the JT-60SA tokamak. These x-ray sources will be especially useful for in situ calibration between plasma discharges. In this paper, laboratory experiments are described that were conducted with a Cu x-ray source, a heated quartz (102) crystal, and a pixelated Pilatus detector to measure the temperature dependent shifts of the Cu Kα1 and Kα2 lines at 1.5405 and 1.5443 Å, respectively, and to evaluate the 2d-lattice constant for the Bragg reflecting crystal planes as a function of temperature, which, in the case of in situ wavelength calibration, would have to be used for numerical analysis of the x-ray spectra from the plasma. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Versatile multi-energy hard x-ray camera to study confined and unconfined fast electron dynamics and anisotropies (Invited).

Author

Barbui, T., Delgado-Aparicio, L. F., Savoye-Peysson, Y., Stratton, B., Dumont, R., Hill, K. W., Pablant, N. A., Wallace, J., and Wisniewski, J.

Subjects
PLASMA physics, PINHOLE cameras, HARD X-rays, THRESHOLD energy, ENERGY levels (Quantum mechanics)
Abstract

A powerful and flexible hard x-ray (HXR) camera has been recently installed and tested on the WEST tokamak (CEA, France) in collaboration with the Princeton Plasma Physics Laboratory. The diagnostic is a pinhole camera fielded with a 2D pixel detector equipped with a 1 mm thick CdTe sensor. The novelty of this diagnostic technique is the detector's capability of adjusting the threshold energy at the pixel level. This innovation provides great flexibility in the energy configuration, allowing simultaneous space, energy, and time resolved x-ray measurements. The novel camera has been used to measure the core radiation from non-Maxwellian (fast) electrons accelerated by Lower Hybrid (LH) waves and also the beam–target emission of tungsten in the divertor region produced by fast electron losses interacting with the target. In addition, anisotropic hard x-ray emission has been detected for the first time at the WEST core and edge plasma, with opposite toroidal intensity trends. Experimental vertical and toroidal HXR profiles have been successfully reproduced with the LH code LUKE. [ABSTRACT FROM AUTHOR]

Published
2024
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3. Statistical data analysis of x-ray spectroscopy data enabled by neural network accelerated Bayesian inference.

Author

MacDonald, M. J., Hammel, B. A., Bachmann, B., Bitter, M., Efthimion, P., Gaffney, J. A., Gao, L., Hammel, B. D., Hill, K. W., Kraus, B. F., MacPhee, A. G., Peterson, L., Schneider, M. B., Scott, H. A., Thorn, D. B., and Yeamans, C. B.

Subjects
MARKOV chain Monte Carlo, STATISTICAL sampling, ATOMIC physics, X-ray spectra, X-ray spectroscopy
Abstract

Bayesian inference applied to x-ray spectroscopy data analysis enables uncertainty quantification necessary to rigorously test theoretical models. However, when comparing to data, detailed atomic physics and radiation transfer calculations of x-ray emission from non-uniform plasma conditions are typically too slow to be performed in line with statistical sampling methods, such as Markov Chain Monte Carlo sampling. Furthermore, differences in transition energies and x-ray opacities often make direct comparisons between simulated and measured spectra unreliable. We present a spectral decomposition method that allows for corrections to line positions and bound–bound opacities to best fit experimental data, with the goal of providing quantitative feedback to improve the underlying theoretical models and guide future experiments. In this work, we use a neural network (NN) surrogate model to replace spectral calculations of isobaric hot-spots created in Kr-doped implosions at the National Ignition Facility. The NN was trained on calculations of x-ray spectra using an isobaric hot-spot model post-processed with Cretin, a multi-species atomic kinetics and radiation code. The speedup provided by the NN model to generate x-ray emission spectra enables statistical analysis of parameterized models with sufficient detail to accurately represent the physical system and extract the plasma parameters of interest. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Results from a synthetic model of the ITER XRCS-Core diagnostic based on high-fidelity x-ray ray tracing.

Author

Pablant, N. A., Cheng, Z., O'Mullane, M., Gao, L., Barnsley, R., Bartlett, M. N., Bitter, M., Bourcart, E., Brown, G. V., De Bock, M., Delgado-Aparicio, L. F., Dunn, C., Fairchild, A. J., Hell, N., Hill, K. W., Klabacha, J., Kraus, F., Lu, D., Magesh, P. B., and Mishra, S.

Subjects
RAY tracing, PYROLYTIC graphite, COMPUTER-aided design, ENGINEERING tolerances, ION temperature
Abstract

A high-fidelity synthetic diagnostic has been developed for the ITER core x-ray crystal spectrometer diagnostic based on x-ray ray tracing. This synthetic diagnostic has been used to model expected performance of the diagnostic, to aid in diagnostic design, and to develop engineering tolerances. The synthetic model is based on x-ray ray tracing using the recently developed xicsrt ray tracing code and includes a fully three-dimensional representation of the diagnostic based on the computer aided design. The modeled components are: plasma geometry and emission profiles, highly oriented pyrolytic graphite pre-reflectors, spherically bent crystals, and pixelated x-ray detectors. Plasma emission profiles have been calculated for Xe44+, Xe47+, and Xe51+, based on an ITER operational scenario available through the Integrated Modelling & Analysis Suite database, and modeled within the ray tracing code as a volumetric x-ray source; the shape of the plasma source is determined by equilibrium geometry and an appropriate wavelength distribution to match the expected ion temperature profile. All individual components of the x-ray optical system have been modeled with high-fidelity producing a synthetic detector image that is expected to closely match what will be seen in the final as-built system. Particular care is taken to maintain preservation of photon statistics throughout the ray tracing allowing for quantitative estimates of diagnostic performance. [ABSTRACT FROM AUTHOR]

Published
2024
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5. Extended X-ray absorption fine structure of dynamically-compressed copper up to 1 terapascal

Author

Sio, H., primary, Krygier, A., additional, Braun, D. G., additional, Rudd, R. E., additional, Bonev, S. A., additional, Coppari, F., additional, Millot, M., additional, Fratanduono, D. E., additional, Bhandarkar, N., additional, Bitter, M., additional, Bradley, D. K., additional, Efthimion, P. C., additional, Eggert, J. H., additional, Gao, L., additional, Hill, K. W., additional, Hood, R., additional, Hsing, W., additional, Izumi, N., additional, Kemp, G., additional, Kozioziemski, B., additional, Landen, O. L., additional, Le Galloudec, K., additional, Lockard, T. E., additional, Mackinnon, A., additional, McNaney, J. M., additional, Ose, N., additional, Park, H.-S., additional, Remington, B. A., additional, Schneider, M. B., additional, Stoupin, S., additional, Thorn, D. B., additional, Vonhof, S., additional, Wu, C. J., additional, and Ping, Y., additional

Published
2023
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7. Streaked sub-ps-resolution x-ray line shapes and implications for solid-density plasma dynamics (invited)

Author

Kraus, B. F., primary, Gao, Lan, additional, Hill, K. W., additional, Bitter, M., additional, Efthimion, P. C., additional, Hollinger, R., additional, Wang, Shoujun, additional, Song, Huanyu, additional, Nedbailo, R., additional, Rocca, J. J., additional, Mancini, R. C., additional, Beatty, C. B., additional, MacDonald, M. J., additional, and Shepherd, R., additional

Published
2022
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9. A new class of variable-radii diffraction optics for high-resolution x-ray spectroscopy at the National Ignition Facility (invited)

Author

Pablant, N. A., primary, Bitter, M., additional, Gao, L., additional, Dozieres, M., additional, Efthimion, P. C., additional, Frisch, G., additional, Hill, K. W., additional, Hordin, T., additional, Kozioziemski, B., additional, Krygier, A., additional, MacDonald, M. J., additional, Ose, N., additional, Ping, Y., additional, Sagan, D., additional, Schneider, M. B., additional, Sio, H., additional, Stoupin, S., additional, and Yakusevitch, Y., additional

Published
2022
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10. Study of Stark broadening of krypton helium-β lines and estimation of electron density and temperature in NIF compressed capsules

Author

Hill, K W, primary, Gao, L, additional, Kraus, B F, additional, Bitter, M, additional, Efthimion, P C, additional, Pablant, N, additional, Schneider, M B, additional, Thorn, D B, additional, Chen, H, additional, Kauffman, R L, additional, Liedahl, D A, additional, MacDonald, M J, additional, MacPhee, A G, additional, Scott, H A, additional, Stoupin, S, additional, Doron, R, additional, Stambulchik, E, additional, Maron, Y, additional, and Lahmann, B, additional

Published
2022
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11. Hot Spot Evolution Measured by High-Resolution X-Ray Spectroscopy at the National Ignition Facility

Author

Gao, Lan, primary, Kraus, B. F., additional, Hill, K. W., additional, Schneider, M. B., additional, Christopherson, A., additional, Bachmann, B., additional, Bitter, M., additional, Efthimion, P., additional, Pablant, N., additional, Betti, R., additional, Thomas, C., additional, Thorn, D., additional, MacPhee, A. G., additional, Khan, S., additional, Kauffman, R., additional, Liedahl, D., additional, Chen, H., additional, Bradley, D., additional, Kilkenny, J., additional, Lahmann, B., additional, Stambulchik, E., additional, and Maron, Y., additional

Published
2022
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15. Design and expected performance of a variable-radii sinusoidal spiral x-ray spectrometer for the National Ignition Facility

Author

Pablant, N. A., primary, Bitter, M., additional, Efthimion, P. C., additional, Gao, L., additional, Hill, K. W., additional, Kraus, B. F., additional, Kring, J., additional, MacDonald, M. J., additional, Ose, N., additional, Ping, Y., additional, Schneider, M. B., additional, Stoupin, S., additional, and Yakusevitch, Y., additional

Published
2021
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16. Experimental Results from the TFTR Tokamak

Author

Hawryluk, R. J., Arunasalam, V., Bell, J. D., Bell, M. G., Bitter, M., Blanchard, W. R., Boody, F., Bretz, N., Budny, R., Bush, C. E., Callen, J. D., Cecchi, J. L., Cohen, S., Colchin, R. J., Combs, S. K., Coonrod, J., Davis, S. L., Dimock, D., Dylla, H. F., Efthimion, P. C., Emerson, L. C., England, A. C., Eubank, H. P., Fonck, R., Fredrickson, E., Goldston, R. J., Grisham, L. R., Grek, B., Groebner, R., Hendel, H., Hill, K. W., Hillis, D. L., Hinnov, E., Hiroe, S., Hulse, R., Hsuan, H., Johnson, D., Kaita, R., Kamperschroer, R., Kaye, S. M., Kilpatrick, S., Kugel, H., LaMarche, P. H., Little, R., Ma, C. H., Manos, D. M., Mansfield, D., McCann, R. T., McCarthy, M., McCune, D. C., McGuire, K., Meade, D. M., Medley, S. S., Milora, S. L., Mikkelsen, D. R., Morris, W., Mueller, D., Murakami, M., Nieschmidt, E., Owens, D. K., Pare, V. K., Park, H., Prichard, B., Ramsey, A., Rasmussen, D. A., Redi, M. H., Roquemore, A. L., Sauthoff, N. R., Schivell, J., Schmidt, G. L., Scott, S. D., Sesnic, S., Shimada, M., Simpkins, J. E., Sinnis, J., Stauffer, F., Stratton, B., Tait, G. D., Taylor, G., Thomas, C. E., Towner, H. H., Ulrickson, M., Von Goeler, S., Weiland, R., Wilgen, J. B., Williams, M., Wong, K. L., Yoshikawa, S., Young, K. M., Zarnstorff, M. C., and Zweben, S.

Published
1987

17. The multi-optics high-resolution absorption x-ray spectrometer (HiRAXS) for studies of materials under extreme conditions

Author

Stoupin, S., primary, Thorn, D. B., additional, Ose, N., additional, Gao, L., additional, Hill, K. W., additional, Ping, Y., additional, Coppari, F., additional, Kozioziemski, B., additional, Krygier, A., additional, Sio, H., additional, Ayers, J., additional, Bitter, M., additional, Kraus, B., additional, Efthimion, P. C., additional, and Schneider, M. B., additional

Published
2021
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19. A new class of focusing crystal shapes for Bragg spectroscopy of small, point-like, x-ray sources in laser produced plasmas

Author

Bitter, M., primary, Pablant, N., additional, Hill, K. W., additional, Gao, Lan, additional, Kraus, B., additional, Efthimion, P. C., additional, Delgado-Apericio, L., additional, Stratton, B., additional, Schneider, M., additional, Coppari, F., additional, Kauffman, R., additional, MacDonald, M. J., additional, MacPhee, A., additional, Ping, Y., additional, Stoupin, S., additional, and Thorn, D., additional

Published
2021
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21. Growing irrigated crops in southern Alberta /

Author

Dubetz, S., Hill, K. W., Russell, G. C., Canada. Dept. of Agriculture, Agriculture and Agri-Food Canada (archive.org), Dubetz, S., Hill, K. W., Russell, G. C., and Canada. Dept. of Agriculture

Subjects
Alberta, Irrigation farming
Published
1962

23. Rest-wavelength Fiducials for the ITER Core Imaging X-ray Spectrometer

Author

Beiersdorfer, P, Brown, G. V, Graf, A. T, Bitter, M, Hill, K. W, Kelley, R. L, Kilbourne, C. A, Leutenegger, M. A, and Porter, F. S

Subjects
Instrumentation And Photography, Plasma Physics
Abstract

Absolute wavelength references are needed to derive the plasma velocities from the Doppler shift of a given line emitted by a moving plasma. We show that such reference standards exist for the strongest x-ray line in neonlike W64+, which has become the line of choice for the ITER (Latin the way) core imaging x-ray spectrometer. Close-by standards are the Hf L3 line and the Ir L2 line, which bracket the W64+ line by 30 eV; other standards are given by the Ir L1 and L2 lines and the Hf L1 and L2 lines, which bracket the W64+ line by 40 and 160 eV, respectively. The reference standards can be produced by an x-ray tube built into the ITER spectrometer. We present spectra of the reference lines obtained with an x-ray microcalorimeter and compare them to spectra of the W64+ line obtained both with an x-ray microcalorimeter and a crystal spectrometer

Published
2012
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26. Correction and verification of x-ray imaging crystal spectrometer analysis on Wendelstein 7-X through x-ray ray tracing.

Author

Pablant, N. A., Langenberg, A., Alonso, J. A., Bitter, M., Bozhenkov, S. A., Ford, O. P., Hill, K. W., Kring, J., Marchuck, O., Svensson, J., Traverso, P., Windisch, T., and Yakusevitch, Y.

Subjects
RAY tracing, X-ray imaging, SPECTROMETERS, PLASMA flow, X-rays, PLASMA diagnostics
Abstract

X-ray ray tracing is used to develop ion-temperature corrections for the analysis of the X-ray Imaging Crystal Spectrometer (XICS) used at Wendelstein 7-X (W7-X) and perform verification on the analysis methods. The XICS is a powerful diagnostic able to measure ion-temperature, electron-temperature, plasma flow, and impurity charge state densities. While these systems are relatively simple in design, accurate characterization of the instrumental response and validation of analysis techniques are difficult to perform experimentally due to the requirement of extended x-ray sources. For this reason, a ray tracing model has been developed that allows characterization of the spectrometer and verification of the analysis methods while fully considering the real geometry of the XICS system and W7-X plasma. Through the use of ray tracing, several important corrections have been found that must be accounted for in order to accurately reconstruct the ion-temperature profiles. The sources of these corrections are described along with their effect on the analyzed profiles. The implemented corrections stem from three effects: (1) effect of sub-pixel intensity distribution during de-curving and spatial binning, (2) effect of sub-pixel intensity distribution during forward model evaluation and generation of residuals, and (3) effect of defocus and spherical aberrations on the instrumental response. Possible improvements to the forward model and analysis procedures are explored, along with a discussion of trade-offs in terms of computational complexity. Finally, the accuracy of the tomographic inversion technique in stellarator geometry is investigated, providing for the first time a verification exercise for inversion accuracy in stellarator geometry and a complete XICS analysis tool-chain. [ABSTRACT FROM AUTHOR]

Published
2021
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27. Layout And Results From The Initial Operation Of The High-resolution X-ray Imaging Crystal Spectrometer On The Large Helical Device

Author

Pablant, N A, primary, Delgado-Apricio, L, additional, Goto, M, additional, Hill, K W, additional, Lzerson, S, additional, Morita, S, additional, Roquemore, A L, additional, Gates, D, additional, Monticello, D, additional, Neilson, H, additional, Reiman, A, additional, Reinke, M, additional, and Rice, J E, additional

Published
2012
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28. High-resolution measurements, line identification, and spectral modeling of K-alpha transitions in Fe XVIII-Fe XXV

Author

Beiersdorfer, P, Phillips, T, Jacobs, V. L, Hill, K. W, Bitter, M, Von Goeler, S, and Kahn, S. M

Subjects
Plasma Physics
Abstract

A detailed analysis of the iron K-alpha emission spectrum covering the wavelength region from 1.840 to 1.940 A is presented. Measurements are made with a high-resolution Bragg crystal spectrometer on the Princeton Large Torus (PLT) tokamak for plasma conditions which closely resemble those of solar flares. A total of 40 features are identified, consisting of either single or multiple lines from eight charge states in iron, Fe XVIII - Fe XXV, and their wavelengths are determined with an accuracy of 0.1-0.4 mA. Many of these features are identified for the first time. In the interpretation of our observations we rely on model calculations that determine the ionic species abundances from electron density and temperature profiles measured independently with nonspectroscopic techniques and that incorporate theoretical collisional excitation and dielectronic recombination rates resulting in the excitation of the 1s2sr2ps configurations. The model calculations also include the effect of diffusive ion transport. Good overall agreement between the model calculations and the observations is obtained, which gives us confidence in our line identifications and spectral modeling capabilities. The results are compared with earlier analyses of the K-alpha emission from the Sun.

Published
1993
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31. Absolute calibration of a time-resolved high resolution x-ray spectrometer for the National Ignition Facility (invited)

Author

Gao, Lan, primary, Kraus, B. F., additional, Hill, K. W., additional, Bitter, M., additional, Efthimion, P., additional, Schneider, M. B., additional, MacPhee, A. G., additional, Thorn, D. B., additional, Kilkenny, J., additional, Ayers, J., additional, Kauffman, R., additional, Chen, H., additional, and Nelson, D., additional

Published
2018
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32. A new toroidal x-ray crystal spectrometer for the diagnosis of high energy density plasmas at the National Ignition Facility

Author

Bitter, M., primary, Hill, K. W., additional, Gao, Lan, additional, Kraus, B. F., additional, Efthimion, P. C., additional, Delgado-Aparicio, L., additional, Pablant, N., additional, Stratton, B., additional, Schneider, M., additional, Coppari, F., additional, Kauffman, R., additional, MacPhee, A. G., additional, Ping, Y., additional, and Thorn, D., additional

Published
2018
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33. Upgrade of X-ray crystal spectrometer for high temperature measurement using neon-like xenon lines on EAST

Author

Hu, R. J., primary, Chen, J., additional, Delgado-Aparicio, L. F., additional, Wang, Q. P., additional, Du, X. W., additional, Shen, J., additional, Yang, X. S., additional, Wang, F. D., additional, Fu, J., additional, Li, Y. Y., additional, Bitter, M., additional, Hill, K. W., additional, Pablant, N. A., additional, Lee, S. G., additional, Shi, Y. J., additional, Wan, B. N., additional, Ye, M. Y., additional, and Lyu, B., additional

Published
2018
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35. Multispecies density peaking in gyrokinetic turbulence simulations of low collisionality Alcator C-Mod plasmas

Author

Massachusetts Institute of Technology. Department of Nuclear Science and Engineering, Massachusetts Institute of Technology. Plasma Science and Fusion Center, Greenwald, Martin J, Howard, Nathaniel Thomas, Hughes Jr, Jerry, Rice, John E, Reinke, Matthew Logan, Podpaly, Yuri A, Ma, Y., Mikkelsen, D. R., Bitter, M., Delgado-Aparicio, L., Hill, K. W., Candy, J., Waltz, R. E., Greenwald, Martin J., Rice, John E., Podpaly, Yuri, Massachusetts Institute of Technology. Department of Nuclear Science and Engineering, Massachusetts Institute of Technology. Plasma Science and Fusion Center, Greenwald, Martin J, Howard, Nathaniel Thomas, Hughes Jr, Jerry, Rice, John E, Reinke, Matthew Logan, Podpaly, Yuri A, Ma, Y., Mikkelsen, D. R., Bitter, M., Delgado-Aparicio, L., Hill, K. W., Candy, J., Waltz, R. E., Greenwald, Martin J., Rice, John E., and Podpaly, Yuri

Abstract

Peaked density profiles in low-collisionality AUG and JET H-mode plasmas are probably caused by a turbulently driven particle pinch, and Alcator C-Mod experiments confirmed that collisionality is a critical parameter. Density peaking in reactors could produce a number of important effects, some beneficial, such as enhanced fusion power and transport of fuel ions from the edge to the core, while others are undesirable, such as lower beta limits, reduced radiation from the plasma edge, and consequently higher divertor heat loads. Fundamental understanding of the pinch will enable planning to optimize these impacts. We show that density peaking is predicted by nonlinear gyrokinetic turbulence simulations based on measured profile data from low collisionality H-mode plasma in Alcator C-Mod. Multiple ion species are included to determine whether hydrogenic density peaking has an isotope dependence or is influenced by typical levels of low-Z impurities, and whether impurity density peaking depends on the species. We find that the deuterium density profile is slightly more peaked than that of hydrogen, and that experimentally relevant levels of boron have no appreciable effect on hydrogenic density peaking. The ratio of density at r/a = 0.44 to that at r/a = 0.74 is 1.2 for the majority D and minority H ions (and for electrons), and increases with impurity Z: 1.1 for helium, 1.15 for boron, 1.3 for neon, 1.4 for argon, and 1.5 for molybdenum. The ion temperature profile is varied to match better the predicted heat flux with the experimental transport analysis, but the resulting factor of two change in heat transport has only a weak effect on the predicted density peaking., United States. Department of Energy (Contract DE-AC02-09CH11466), United States. Department of Energy (Contract DE-FC02-99ER54512), United States. Department of Energy (Contract DE-FG02-95ER54309)

Published
2017

36. Discharge Control and Evolution in TFTR

Author

Mueller, D., Bell, M., Boody, F., Bush, C., Cecchi, J. L., Davis, S., Dylla, H. F., Efthimion, P. C., Hawryluk, R. J., Hill, K. W., Kilpatrick, S., LaMarche, P. H., Manos, D., McCune, D., Medley, S. S., Milora, S., Murakami, M., Owens, D. K., Schivell, J., Schmidt, G., Sesnic, S., Stratton, B., Tait, G., Ulrickson, M., Wong, K. L., Woolley, R. D., Zarnstorff, M. C., Zichichi, Antonino, editor, and Knoepfel, Heinz, editor

Published
1986
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39. Publisher’s Note: “Multi-energy x-ray detector calibration for Te and impurity density (nZ) measurements of MCF plasmas” [Rev. Sci. Instrum. 87, 11E320 (2016)]

Author

Maddox, J., primary, Pablant, N., additional, Efthimion, P., additional, Delgado-Aparicio, L., additional, Hill, K. W., additional, Bitter, M., additional, Reinke, M. L., additional, Rissi, M., additional, Donath, T., additional, Luethi, B., additional, and Stratton, B., additional

Published
2016
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40. Development of a high resolution x-ray spectrometer for the National Ignition Facility (NIF)

Author

Hill, K. W., primary, Bitter, M., additional, Delgado-Aparicio, L., additional, Efthimion, P. C., additional, Ellis, R., additional, Gao, L., additional, Maddox, J., additional, Pablant, N. A., additional, Schneider, M. B., additional, Chen, H., additional, Ayers, S., additional, Kauffman, R. L., additional, MacPhee, A. G., additional, Beiersdorfer, P., additional, Bettencourt, R., additional, Ma, T., additional, Nora, R. C., additional, Scott, H. A., additional, Thorn, D. B., additional, Kilkenny, J. D., additional, Nelson, D., additional, Shoup, M., additional, and Maron, Y., additional

Published
2016
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43. A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited)

Author

Nilson, P. M., primary, Ehrne, F., additional, Mileham, C., additional, Mastrosimone, D., additional, Jungquist, R. K., additional, Taylor, C., additional, Stillman, C. R., additional, Ivancic, S. T., additional, Boni, R., additional, Hassett, J., additional, Lonobile, D. J., additional, Kidder, R. W., additional, Shoup, M. J., additional, Solodov, A. A., additional, Stoeckl, C., additional, Theobald, W., additional, Froula, D. H., additional, Hill, K. W., additional, Gao, L., additional, Bitter, M., additional, Efthimion, P., additional, and Meyerhofer, D. D., additional

Published
2016
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44. Measurement of helium-like and hydrogen-like argon spectra using double-crystal X-ray spectrometers on EAST

Author

Lyu, B., primary, Chen, J., additional, Hu, R. J., additional, Wang, F. D., additional, Li, Y. Y., additional, Fu, J., additional, Shen, Y. C., additional, Bitter, M., additional, Hill, K. W., additional, Delgado-Aparicio, L. F., additional, Pablant, N., additional, Lee, S. G., additional, Ye, M. Y., additional, Shi, Y. J., additional, and Wan, B. N., additional

Published
2016
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46. Lineshape spectroscopy with a very high resolution, very high signal-to-noise crystal spectrometer

Author

Beiersdorfer, P., primary, Magee, E. W., additional, Brown, G. V., additional, Chen, H., additional, Emig, J., additional, Hell, N., additional, Bitter, M., additional, Hill, K. W., additional, Allan, P., additional, Brown, C. R. D., additional, Hill, M. P., additional, Hoarty, D. J., additional, Hobbs, L. M. R., additional, and James, S. F., additional

Published
2016
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48. On the Design of the NIF Continuum Spectrometer.

Author

Thorn, D. B., MacPhee, A., Ayers, J., Galbraith, J., Hardy, C. M., Izumi, N., Bradley, D. K., Pickworth, L. A., Bachmann, B., Kozioziemski, B., Landen, O., Clark, D., Schneider, M. B., Hill, K. W., Bitter, M., Nagel, S., Bell, P. M., Person, S., Khater, H. Y., and Smith, C.

Published
2017
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49. ITER Core Imaging X-ray Spectroscopy: Atomic Physics Issues.

Author

Beiersdorfer, P., Clementson, J., Widmann, K., Bitter, M., Hill, K. W., Johnson, D., Barnsley, R., Chung, H. K., and Safronova, U. I.

Subjects
X-ray spectroscopy, DOPPLER broadening, ION temperature, ATOMIC physics
Abstract

The Core Imaging X-Ray Spectrometer (CIXS) will be employed for measurements of the ion temperature and of the toroidal rotation velocity, Ti and vφ, respectively, as a function of the radius of ITER plasmas. The diagnostic is based on precision determinations of the Doppler broadening, centroid shift, and intensity of the lines of highly ionized heavy impurities using a curved Bragg crystal spectral disperser and imager. The ions under consideration for the diagnostic are those of tungsten, krypton, xenon, iron, and argon. A detailed discussion is given of the need for atomic physics experiments and calculations involving the primary diagnostic lines and their collisional and dielectronic satellites. Such experiments and calculations define the instrument parameters, determine the diagnostic uncertainties, and provide paths for extending the diagnostic capabilities to measure impurity concentrations, electron temperature, and ion transport parameters. Enabling the diagnostic to measure radially dependent ion transport coefficients, in particular, requires a large amount of high-quality atomic data in the form of reliable excitation, ionization, and recombination rate coefficients as well as ionization balance calculations which make use of these data. Because core imaging spectrometers are being developed and implemented on present-day magnetic fusion devices, much of the atomic data are already needed and can be tested in the analysis of existing spectra recorded by these diagnostics. [ABSTRACT FROM AUTHOR]

Published
2017
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