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Your search keyword '"Büchl, K."' showing total 20 results
Start Over Author "Büchl, K." Publication Type Academic Journals
20 results on '"Büchl, K."'

2. Pellet imaging techniques in the ASDEX tokamak.

Author

Wurden, G. A., Büchl, K., Hofmann, J., Lang, R., Loch, R., Rudyj, A., and Sandmann, W.

Subjects
*TOKAMAKS, *INERTIAL confinement fusion, *ABLATION (Aerothermodynamics)
Abstract

As part of a USDOE/ASDEX collaboration, a detailed examination of pellet ablation in ASDEX with a variety of diagnostics has allowed a better understanding of a number of features of hydrogen ice pellet ablation in a plasma. In particular, fast-gated photos with an intensified Xybion CCD video camera allow in situ velocity measurements of the pellet as it penetrates the plasma. With time resolution of typically 100 ns and exposures every 50 μs, the evolution of each pellet in a multipellet ASDEX tokamak plasma discharge can be followed. When the pellet cloud track has striations, the light intensity profile through the cloud is hollow (dark near the pellet), whereas at the beginning or near the end of the pellet trajectory the track is typically smooth (without striations) and has a gaussian-peaked light emission profile. New, single pellet Stark broadened Dα, Dβ, and Dγ spectra, obtained with a tangentially viewing scanning mirror/spectrometer with Reticon array readout, are consistent with cloud densities of 2×1017 cm-3 or higher in the regions of strongest light emission. A spatially resolved array of Dα detectors shows that the light variations during the pellet ablation are not caused solely by a modulation of the incoming energy flux as the pellet crosses rational q surfaces, but instead are a result of dynamic, nonstationary, ablation process. [ABSTRACT FROM AUTHOR]

Published
1990
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3. Pellet injection on the ZT-40M reversed field pinch.

Author

Watt, R. G., Wurden, G. A., Weber, P. G., Büchl, K., and Spanos, E. K.

Subjects
REVERSED field pinches, INERTIAL confinement fusion, TOKAMAKS
Abstract

The four barrel pneumatic pellet injector originally used on the Alcator C tokamak at MIT has been reconfigured for use on the ZT-40M reversed field pinch (RFP) at Los Alamos National Laboratory. The lower temperature and density in this device require operation at velocities significantly lower than on Alcator. Allowing a 2-s warmup prior to firing the injector has enabled operation with pressures as low as 40 psig and velocities ranging as low as 200 m/s with H2 pellets, without major cryostat modification. Initial injection experiments in the ZT-40M plasma have verified that pellet refueling is effective for density control, but the net particle inventory increase is less than might be expected based on simple models. Indications of nonoptimal penetration and curvature of the pellet trajectory, in addition to comparable time scales for particle confinement and pellet transit, may account for this. [ABSTRACT FROM AUTHOR]

Published
1987
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8. Impurity accumulation in plasma regimes with high energy confinement

Author

Ran, L.B., Roberts, D.E., Yang, H.R., Dodel, G., Gentle, K., Von Goeler, S., Holzhauer, E., Hübner, K., Keilhacker, M., Korotkov, A., Luce, T.C., Miura, Y., Tsois, N., Würz, H., Fussmann, G., Hofmann, J., Janeschitz, G., Krieger, K., Müller, E.R., Nolte, R., Röhr, H., Steuer, K.H., Becker, G., Bomba, B., Bruhns, H., Büchl, K., Carlson, A., Eberhagen, A., Fahrbach, H.-U., Gehre, O., Gernhardt, J., Giannone, L., Von Gierke, G., Glock, E., Gruber, O., Haas, G., Herrmann, H., Kaesdorf, S., Karger, F., Kaufmann, M., Klüber, O., Kornherr, M., Lackner, K., Lang, R., Lee, P., Lisitano, G., Mast, F., Mayer, H.M., McCormick, K., Meisel, D., Mertens, V., Murmann, H., Neuhauser, J., Niedermeyer, H., Noterdaeme, J.M., Poschenrieder, W., Preis, R., Rapp, H., Rudyj, A., Sandmann, W., Schneider, F., Schnider, U., Siller, G., Simmet, E., Speth, E., Söldner, F., Stäbler, A., Steinmetz, K., Stroth, U., Vollmer, O., and Zasche, D.

Published
1989
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9. Recycling studies in the ASDEX divertor with pellet or gas puff refuelling

Author

Haas, G., Kaufmann, M., Lang, R.S., ASDEX Team, PELLET Team, Mertens, V., Niedermeyer, H., Sandmann, W., Becker, G., Bosch, H.S., Brocken, H., Büchl, K., Eberhagen, A., Fussmann, G., Gehre, O., Gernhardt, J., Gierke, G., Glock, E., Gruber, O., Hofmann, J., Izvozchikov, A., Janeschitz, G., Karger, F., Keilhacker, M., Klüber, O., Kornherr, M., Lackner, K., Lenoci, M., Lisitano, G., Mast, F., Mayer, H.M., McCormick, K., Meisel, D., Müller, E.R., Murmann, H., Neuhauser, J., Pietrzyk, Z.A., Poschenrieder, W., Rapp, H., Riedler, H., Röhr, H., Roth, J., Ryter, F., Schneider, F., Setzensack, C., Siller, G., Smeulders, P., Söldner, F.X., Speth, E., Steuer, K.-H., Tsois, N., Vlases, G., Vollmer, O., Wagner, F., Ugniewski, S., and Zasche, D.

Published
1987
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11. Pellet injection with improved confinement in ASDEX.

Author

Kaufmann, M., Büchl, K., Fussmann, G., Gehre, O., Grassie, K., Gruber, O., Haas, G., Janeschitz, G., Kornherr, M., Lackner, K., Lang, R. S., Mast, K. F., McCormick, K., Mertens, V., Neuhauser, J., Niedermeyer, H., Sandmann, W., Schneider, W., Zasche, D., and Zehrfeld, H. -P

Published
1988
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15. Divertor tokamak operation at high densities on ASDEX Upgrade.

Author

Gruber, O., Mertens, V., Neuhauser, J., Ryter, F., Suttrop, W., Albrecht, M., Alexander, M., Asmussen, K., Becker, G., Behler, K., Behringer, K., Bergmann, A., Bessenrodt-Weberpals, M., Borras, K., Bosch, H-S, Braams, B., Brambilla, M., Braun, F., Brinkschulte, H., and Büchl, K.

Published
1997
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19. Observation of continuous divertor detachment in H-mode discharges in ASDEX upgrade.

Author

Gruber O, Kallenbach A, Kaufmann M, Lackner K, Mertens V V, Neuhauser J, Ryter F, Zohm H, Bessenrodt-Weberpals M, Büchl K, Fiedler S, Field A, Fuchs C, Garcia-Rosales C, Haas G, Herrmann A, Herrmann W, Hirsch S, Köppendörfer W, Lang P, Lieder G, Mast K, Pitcher CS, Schittenhelm M, Stober J, Suttrop W, Troppmann M, Weinlich M, Albrecht M, Alexander M, Asmussen K, Ballico M, Behler K, Behringer K, Bosch HS, Brambilla M, Carlson A, Coster D, Cupido L, DeBlank HJ, De Pena Hempel S, Deschka S, Dorn C, Drube R, Dux R, Eberhagen A, Engelhardt W, Fahrbach H, Feist H, Fieg D, Fu beta mann G, Gehre O, Gernhardt J, Ignacz P, Jüttner B, Junker W, Kass T, Kiemer K, Kollotzek H, Kornherr M, Krieger K, Kurzan B, Lang R, and Laux M

Published
1995
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20. Focus detector as an aid for focusing a laser on a target.

Author

Büchl K

Abstract

An apparatus is described which assesses the focus of a laser on a surface. An image of the focus is scanned by fiber optics. A rotating slit together with a photodetector behind the fibers detects whether a fiber is illuminated or not. When the focus coincides with the surface of the target, the number of illumiated fibers is a minimum. The apparatus is especially advantageous for adjustment when the radiation is not visible, for example, with neodymium lasers or with frequency doubled radiation from ruby lasers.

Published
1970
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