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499 results on '"Hofstadter, R."'

4. ELECTRON INDUCED FISSION IN U^8, Bi209 AND TalSl

Author

Bowman, H.R., Gatti, R.C, Jared, R.C, Kilian, G., Moretto, L.G., Thompson, S.G., Croissiaux, M.R., Heisenberg, J.H., Hofstadter, R., Middleman, L.M., and Yearian, M.R.

Published
1967

5. Measurement of the decay of the Υ(1S) and Υ(2S) resonances to muon pairs

Author

Kobel, M., Antreasyan, D., Bartels, H. W., Besset, D., Bieler, Ch., Bienlein, J. K., Bizetti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Janssen, H., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kloiber, T., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, R., Leffler, S., Lekebusch, R., Lesiak, T., Litke, A. M., Lockman, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., Maschmann, W., McBride, P., Messing, F., Metzger, W. J., Meyer, H., Monteleoni, B., Muryn, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D. A., Zschorsch, P., and Crystal Ball Collaboration

Published
1992
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6. Analysis of the 33-133-133-1final state in photon-photon collisions

Author

Karch, K., Antreasyan, D., Bartels, H. W., Besset, D., Bieler, Ch., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Janssen, H., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Koiber, T., Kobel, M., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, S., Leffler, S., Lekebusch, R., Lesiak, T., Litke, A. M., Lockman, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., Maschmann, W., McBride, P., Messing, F., Metzger, W. J., Meyer, H., Monteleoni, B., Muryn, B., Nernst, R., Niczyporul, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D. A., Zschorsch, P., and Crystal Ball Collaboration

Published
1992
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7. Search for radiativeB meson decays

Author

Lesiak, T., Antreasvan, D., Bartels, H. W., Besset, D., Bieler, Ch., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Janssen, H., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kloiber, T., Kobel, M., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, R., Leffler, S., Lekebusch, R., Litke, A. M., Lockman, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., Maschmann, W., McBride, P., Messing, F., Metzger, W. J., Meyer, H., Monteleoni, B., Muryn, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D. A., Zschorsch, P., and Crystal Ball Collaboration

Published
1992
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8. Measurement of π0 and η meson production ine + e − annihilation at $$\sqrt s$$ near 10 GeV

Author

Bieler, Ch., Antreasyan, D., Bartels, H. W., Besset, D., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Janssen, H., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kloiber, T., Kobel, M., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, R., Leffler, S., Lekebusch, R., Litke, A. M., Lockman, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., Maschmann, W., McBride, P., Messing, F., Metzger, W. J., Meyer, H., Monteleoni, B., Muryn, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. I., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D. A., and Zschorsch, P.

Published
1991
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9. InclusiveJ/ψ production in decays ofB mesons

Author

Maschmann, W., Antreasyan, D., Bartels, H. W., Besset, D., Bieler, Ch., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Janssen, H., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kloiber, T., Kobel, M., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, R., Leffler, S., Lekebusch, R., Litke, A. M., Lockman, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., McBride, P., Messing, F., Metzger, W. J., Meyer, H., Monteleoni, B., Muryn, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D. A., Zschorsch, P., and Crystal Ball Collaboration

Published
1990
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10. Observation of the exclusive decayB→evD * and search forB→evπ 0

Author

Antreasyan, D., Bartels, H. W., Bieler, C., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brockmüller, K., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Coyne, D., Fairfield, K., Folger, G., Fridman, A., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Janssen, H., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kobel, M., Koch, W., König, A. C., Königsmann, K., Krüger, S., Landi, G., Leffler, S., Lekebusch, R., Lesiak, T., Litke, A. M., Lowe, S., Lurz, B., Marsiske, H., Maschmann, W., McBride, P., Metzger, W. J., Meyer, H., Monteleoni, B., Muryn, B., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Porter, F. C., Reidenbach, M., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., van Uitert, B., Van de Walle, R. T., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D. A., and Crystal Ball Collaboration

Published
1990
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11. First observation of the reactionγγ→π 2→π 0 π 0 π 0

Author

Antreasyan, D., Bartels, H. W., Besset, D., Bieler, Ch., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Janssen, H., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kloiber, T., Kobel, M., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, R., Leffler, S., Lekebusch, R., Litke, A. M., Lockman, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., Maschmann, W., McBride, P., Messing, F., Metzger, W. J., Meyer, H., Monteleoni, B., Muryn, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D. A., Zschorsch, P., and Crystal Ball Collaboration

Published
1990
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12. Performance of the EGRET astronomical gamma ray telescope

Author

Nolan, P.L., Bertsch, D.L., Fichtel, C.E., Hartman, R.C., Hofstadter, R., Hughes, E.B., Hunter, S.D., Kanbach, G., Kniffen, D.A., Lin, Y.C., Mattox, J.R., Mayer-Hasselwander, H.A., Michelson, P.F., Von Montigny, C., Pinkau, K., Rothermel, H., Schneid, E., Sommer, M., Sreekumar, P., and Thompson, D.J.

Subjects
Gamma rays -- Research, Telescope -- Research, Orbiting astronomical observatories -- Research, Business, Electronics, Electronics and electrical industries
Abstract

The performance of the Energetic Gamma Ray Experiment Telescope (EGRET) was evaluated while on orbit. EGRET consist of a multilayer spark chamber, a plastic scintillator trigger hodoscope, a NaI(Tl) calorimeter and a plastic scintillator anticoincidence dome to reject charged particles. The gamma ray telescope measures the highest-energy photons and tests show that its time resolution, angular resolution and gamma ray detection efficiency are within normal limits.

Published
1992

13. Calibration of the Energetic Gamma-Ray Experiment Telescope (EGRET) for the Compton Gamma-Ray Observatory

Author

Thompson, D. J, Bertsch, D. L, Fichtel, C. E, Hartman, R. C, Hofstadter, R, Hughes, E. B, Hunter, S. D, Hughlock, B. W, Kanbach, G, and Kniffen, D. A

Subjects
Spacecraft Instrumentation
Abstract

The calibration of the (EGRET) prior to its launch aboard the Compton Gamma Ray Observatory, the continuing calibration after launch, and instrument-performance results based on calibrations and early postlaunch data, are described. Particular attention is given to the effective area, the annular resolution, and the energy resolution.

Published
1993
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14. Plastic scintillator block as photon beam monitor for EGRET calibration

Author

Lin, Y. C, Hofstadter, R, Nolan, P. L, Walker, A. H, Mattox, J. R, and Hughes, E. B

Subjects
Instrumentation And Photography
Abstract

The EGRET (Energetic Gamma Ray Experiment Telescope) detector has been calibrated at SLAC (Stanford Linear Accelerator) and, to a lesser degree, at the MIT Bates Linear Accelerator Center. To monitor the photon beams for the calibration, a plastic scintillator block, 5 cm x 5 cm in cross section, 15 cm in length, and viewed by a single photomultiplier tube, was used for the entire beam energy range of 15 MeV to 10 GeV. The design operation, and method of analysis of the beam intensity are presented. A mathematical framework has been developed to treat the general case of a beam with multiphoton beam pulses and with a background component. A procedure to deal with the fluctuations of the beam intensity over a data-taking period was also developed. The photon beam monitor is physically sturdy, electronically steady, simple to construct, and easy to operate. Its major merits lie in its sheer simplicity of construction and operation and in the wide energy range it can cover.

Published
1991
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16. New Results for Rare Muon Decays

Author

Mischke, R. E., Bolton, R. D., Bowman, J. D., Cooper, M. D., Frank, J. S., Hallin, A. L., Heusi, P. A., Hoffman, C. M., Hogan, G. E., Mariam, F. G., Matis, H. S., Nagle, D. E., Piilonen, L. E., Sandberg, V. D., Sanders, G. H., Sennhauser, U., Werheck, R., Williams, R. A., Wilson, S. L., Hofstadter, R., Hughes, E. B., Ritter, M. W., Grosnick, D., Wright, S. C., Highland, V. L., McDonough, J., and Klapdor, Hans Volker, editor

Published
1986
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19. Recent high energy electron investigations at Stanford University

Author

Buchanan, C. D., Collard, H., Crannell, C., Frosch, R., Griffy, T. A., Hofstadter, R., Hughes, E. B., Nöldeke, G. K., Oakes, R. J., van Oostrum, K. J., Rand, R. E., Suelzle, L., Yearian, M. R., Clark, B. C., Herman, R., Ravenhall, D. G., Höhler, Gerhard, Fujimori, Atsushi, Kühn, Johann, Müller, Thomas, Steiner, Frank, Trümper, Joachim E., Wölfle, Peter, and Woggon, Ulrike

Published
1965
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24. Experimental upper limits for the hadronic transitions Υ(2S)→ηΥ(1S) and Υ(2S)→π0Υ(1S)

Author

Lurz, B., Antreasyan, D., Besset, D., Bienlein, J. K., Bloom, E. D., Brock, I., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Edwards, C., Engler, A., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Godfrey, G., Heimlich, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Keh, S., Kilian, H., Kirkbride, I., Kloiber, T., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Lee, R., Leffler, S., Lekebusch, R., Litke, A. M., Lockman, W., Lowe, S., Marlow, D., Maschmann, W., Matsui, T., Messing, F., Metzger, W. J., Monteleoni, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schwarz, A., Sievers, D., Skwarnicki, T., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., Van de Walle, R. T., Vogel, H., Volland, U., Wacker, K., Walk, W., Wegener, H., Williams, D., Zschorsch, P., and Crystal Ball Collaboration

Published
1987
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25. The electron spectrum fromB meson decays

Author

Wachs, K., Antreasyan, D., Bartels, H. W., Bieler, Ch., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brockmüller, K., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Coyne, D., Drews, G., Fairfield, K., Folger, G., Fridman, A., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kobel, M., Koch, W., König, A. C., Königsmann, K., Krüger, S., Landi, G., Leffler, S., Lekebusch, R., Litke, A. M., Lowe, S., Lurz, B., Marsiske, H., Maschmann, W., McBride, P., Meyer, H., Muryn, B., Metzger, W. J., Monteleoni, B., Niczyporuk, B., Nowak, G., Peck, C., Pegel, C., Pelfer, P. G., Porter, F. C., Reidenbach, M., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Selonke, F., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., van Uitert, B., Van de Walle, R. T., Voigt, A., Volland, U., Wacker, K., Walk, W., Wegener, H., Williams, D., and Crystal Ball Collaboration

Published
1989
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26. Determination ofГ ee of the Υ(1S) and Υ(2S) resonances, and measurement ofR atW=9.39 GeV

Author

Jakubowski, Z., Antreasyan, D., Bartels, H. W., Besset, D., Bieler, Ch., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cowan, R., Coyne, D., Drews, G., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Graaf, K., Heimlich, F. H., Heinsius, F. H., Hofstadter, R., Irion, J., Janssen, H., Karch, K., Keh, S., Kiel, T., Kilian, H., Kirkbride, I., Kloiber, T., Kobel, M., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, R., Leffler, S., Lekebusch, R., Litke, A. M., Lockmann, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., Maschmann, W., McBride, P., Meyer, H., Muryn, B., Messing, F., Metzger, W. J., Monteleoni, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pegel, C., Pelfer, P. G., Pollock, B., Pols, C., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schmitt, P., Schotanus, J., Schütte, J., Schwarz, A., Selonke, F., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D., Zschorsch, P., and Crystal Ball Collaboration

Published
1988
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28. Search for radiative ϒ(1S) decays into light mesons

Author

Schmitt, P., Antreasyan, D., Bartels, H. W., Besset, D., Bieler, Ch., Bienlein, J. K., Bizzeti, A., Bloom, E. D., Brock, I., Brockmüller, K., Cabenda, R., Cartacci, A., Cavalli-Sforza, M., Clare, R., Compagnucci, A., Conforto, G., Cooper, S., Cowan, R., Coyne, D., Engler, A., Fairfield, K., Folger, G., Fridman, A., Gaiser, J., Gelphman, D., Glaser, G., Godfrey, G., Heimlich, F. H., Hofstadter, R., Irion, J., Jakubowski, Z., Karch, K., Keh, S., Kilian, H., Kirkbride, I., Kloiber, T., Kobel, M., Koch, W., König, A. C., Königsmann, K., Kraemer, R. W., Krüger, S., Landi, G., Lee, R., Leffler, S., Lekebusch, R., Lockman, W., Lowe, S., Lurz, B., Marlow, D., Marsiske, H., Maschmann, W., McBride, P., Meyer, H., Muryn, B., Messing, F., Metzger, W. J., Monteleoni, B., Nernst, R., Niczyporuk, B., Nowak, G., Peck, C., Pelfer, P. G., Pollock, B., Porter, F. C., Prindle, D., Ratoff, P., Reidenbach, M., Renger, B., Rippich, C., Scheer, M., Schotanus, J., Schütte, J., Schwarz, A., Sievers, D., Skwarnicki, T., Stock, V., Strauch, K., Strohbusch, U., Tompkins, J., Trost, H. J., van Uitert, B., Van de Walle, R. T., Vogel, H., Voigt, A., Volland, U., Wachs, K., Wacker, K., Walk, W., Wegener, H., Williams, D., Zschorsch, P., and Crystal Ball Collaboration

Published
1988
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40. Ensayo de vida de lámparas halógenas de bajo voltaje con reflector dicroico

Author

Hofstadter, R and Vignolo, Mario

Subjects
POTENCIA
Abstract

El uso masivo que se ha producido en el Uruguay de la lámpara halógena de bajo voltaje con reflector dicroico (generalmente llamada lámpara dicroica) ha despertado el especial interés de proyectistas y técnicos en iluminación respecto a las características particulares de estas lámparas, en especial, en lo que se refiere a su vida media. Se ha observado que en muchas instalaciones donde se han utilizado estas lámparas la frecuencia de falla ha sido muy superior a la esperada. Por otra parte, se ha observado una gran dispersión de estos valores dependiendo del fabricante, aún en los casos en que la vida media nominal especificada por todos ellos era la misma. El Grupo LUXROU, integrado por profesionales que trabajan en iluminación y por docentes del Grupo de Fotometría e Iluminación de la Facultad de Ingeniería, se propuso realizar un ensayo de vida a tensión nominal controlada, tomando una muestra de lámparas de todos los fabricantes disponibles en el Uruguay, resultando en un total de 60 lámparas ensayadas. Luego de aproximadamente dos años de ensayos se presentan en este trabajo los resultados del mismo. Se realiza un especial análisis de la evolución del flujo de las lámparas, realizando una comparación con la evolución esperada, utilizando los datos disponibles del fabricante. Asimismo se muestran los momentos de muerte de las lámparas y la evolución de las características del reflector dicroico. Por otra parte, y como consecuencia de la experiencia obtenida, se analizan cuáles deben ser las mejores condiciones de instalación para estas lámparas de forma de asegurar un desempeño adecuado de las mismas.

Published
2002

41. The project EGRET (Energetic Gamma-Ray Experiment Telescope) on NASA's Gamma-Ray Observatory (GRO)

Author

Kanbach, G, Bertsch, D. L, Fichtel, C. E, Hartman, R. C, Hunter, S. D, Kniffen, D. A, Hughlock, B. W, Favale, A, Hofstadter, R, and Hughes, E. B

Subjects
Astronomy
Abstract

The design, predicted performance, and scientific objectives of the 20-30,000-MeV gamma-ray telescope EGRET for the NASA GRO spacecraft (scheduled for Space Shuttle launch to a 450-km 28.5-deg orbit in 1990) are reviewed. The other GRO instruments are briefly characterized, including the burst and transient-source experiment, the oriented scintillation spectrometer, and the imaging Compton telescope. EGRET comprises an anticoincidence system, a spark chamber, a triggering telescope, an NaI total-absorption spectrometer, a gas supply capable of refilling the chamber four times, and support electronics. EGRET will operate with energy resolution about 15 percent, effective area about 2000 sq cm, sensitivity about 5 x 10 to the -8th/sq cm sec, angular resolution 0.1-0.4 deg, and FOV about 40 deg FWHM. Observations of Galactic point sources, Galactic and extragalactic diffuse emission, gamma-ray bursts, and solar flares are planned.

Published
1988

42. Properties of a large NaI(Tl) spectrometer for the energy measurement of high-energy gamma rays on the Gamma Ray Observatory

Author

Hughes, E. B, Finman, L. C, Hofstadter, R, Lepetich, J. E, and Lin, Y. C

Subjects
Spacecraft Instrumentation
Abstract

A large NaI(Tl) spectrometer is expected to play a crucial role in the measurement of the energy spectra from an all-sky survey of high-energy celestial gamma rays on the Gamma Ray Observatory. The crystal size and requirements of space flight have resulted in a novel crystal-packaging and optics combination. The structure of this spectrometer and the operating characteristics determined in a test program using high energy positrons are described.

Published
1986

43. EGRET - The high energy gamma ray telescope for NASA's Gamma Ray Observatory

Author

Fichtel, C. E, Bertsch, D. L, Hartman, R. C, Kniffen, D. A, Thompson, D. J, Hofstadter, R, Hughes, E. B, Campbell-Finman, L. E, Pinkau, K, and Mayer-Hasselwander, H

Subjects
Astronomy
Abstract

The EGRET high energy gamma-ray telescope under development for NASA's Gamma Ray Observatory will have an energy range of approximately 12 to 30,000 MeV, energy resolution of about 15 percent FWHM over most of that range, an effective area of about 2000 sq cm at high energies, and single photon angular accuracy of approximately 2 deg at 100 MeV, less than 0.1 deg above 5 GeV. This instrument can locate strong sources to an accuracy of about 5 arc min. The instrument utilizes a set of digital spark chambers interleaved with tantalum foils for detection and identification of gamma-ray events, and a large NaI(Tl) scintillator for energy determination. The system is triggered by a coincidence matrix using two arrays of plastic scintillation counters and a large plastic scintillator anticoincidence dome that rejects incident charged particles.

Published
1983

44. Measurement of the positron-electron reaction which produces a gamma ray pair in the region psi/3684

Author

Hughes, E. B, Beron, B. L, Carrington, R. L, Ford, R. L, Hofstadter, R, Liberman, A. D, Martin, T. W, Oneill, L. H, Simpson, J. W, and Hilger, E

Subjects
Nuclear And High-Energy Physics
Abstract

An experiment was conducted to measure gamma ray pairs produced in the electron-positron reaction in the region of psi(3684) resonance. The apparatus consisted of two identical spectrometers mounted in a collinear configuration about the beam interaction region. Graphs are presented for the coplanarity angle between reconstructed gamma ray directions, for the scattering and energy deposition of gamma rays in the two crystals used, and for the observed rate of annihilation reactions as a function of center of mass energy.

Published
1976

45. Measurements of selected psi /3684/ branching ratios from a study of secondary lepton pairs

Author

Hilger, E, Beron, B. L, Ford, R. L, Hofstadter, R, Howell, R. L, Hughes, E. B, Liberman, A. D, Martin, T. W, Oneill, L. H, and Simpson, J. W

Subjects
Nuclear And High-Energy Physics
Abstract

The measurements considered were made at the electron-positron storage ring at the Stanford Linear Accelerator Center. The apparatus used consists of two identical spectrometers mounted in a collinear configuration about the beam-interaction region. The energies of secondary electrons or positrons are measured with good resolution in large NaI(Tl) total-absorption detectors. Data accumulated without gamma-ray converters were examined for electron-positron pairs. The data taken with gamma-ray converters in place and at center-of-mass energies within 1 MeV of the resonance energy were scanned for evidence of either charged particles or converted gamma rays accompanying the detected muon pairs.

Published
1975
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46. Search for monenergetic gamma rays from psi /3684/ decay

Author

Simpson, J. W, Beron, B. L, Ford, R. L, Hofstadter, R, Howell, R. L, Hughes, E. B, Liberman, A. D, Martin, T. W, Oneill, L. H, and Hilger, E

Subjects
Nuclear And High-Energy Physics
Abstract

Results are reported of a search for monoenergetic gamma rays with energies above 50 MeV arising from psi (3684) decay. The measurements were made by operating an electron-positron storage ring at a center-of-mass energy of 3684 MeV and detecting the secondary gamma rays with large-crystal NaI(T1) spectrometers. No significant evidence is found for the emission of such radiation, and upper limits are placed on such emissions for energies above 50 MeV.

Published
1975
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47. The use of an active coded aperture for improved directional measurements in high energy gamma-ray astronomy

Author

Johansson, A, Beron, B. L, Campbell, L, Eichler, R, Hofstadter, R, Hughes, E. B, Wilson, S, and Gorodetsky, P

Subjects
Astronomy
Abstract

The coded aperture, a refinement of the scatter-hole camera, offers a method for the improved measurement of gamma-ray direction in gamma-ray astronomy. Two prototype coded apertures have been built and tested. The more recent of these has 128 active elements of the heavy scintillator BGO. Results of tests for gamma-rays in the range 50-500 MeV are reported and future application in space discussed.

Published
1980

48. Characteristics of the telescope for high energy gamma-ray astronomy selected for definition studies on the Gamma Ray Observatory

Author

Hughes, E. B, Hofstadter, R, Rolfe, J, Johansson, A, Bertsch, D. L, Cruickshank, W. J, Ehrmann, C. H, Fichtel, C. E, Hartman, R. C, and Kniffen, D. A

Subjects
Astronomy
Abstract

The high energy gamma-ray telescope selected for definition studies on the Gamma Ray Observatory provides a substantial improvement in observational capability over earlier instruments. It will have about 20 times more sensitivity, cover a much broader energy range, have considerably better energy resolution and provide a significantly improved angular resolution. The design and performance are described.

Published
1980

49. Characteristics of the Telescope for High Energy Gamma-ray Astronomy Selected for Definition Studies on the Gamma Ray Observatory

Author

Hughes, E. B, Hofstadter, R, Johansson, A, Rolfe, J, Bertsch, D. L, Cruickshank, W. J, Ehrmann, C. H, Fichtel, C. E, Hartman, R. C, and Kniffen, D. A

Subjects
Astronomy
Abstract

The high energy gamma-ray selected for definition studies on the Gamma Ray Observatory provides a substantial improvement in observational capability over earlier instruments. It will have about 20 times more sensitivity, cover a much broader energy range, have considerably better energy resolution and provide a significantly improved angular resolution. The design and performance are described.

Published
1979

50. Gamma-ray astrophysics - A new look at the universe

Author

Trombka, J, Fichtel, C, Grindlay, J, and Hofstadter, R

Subjects
Astrophysics
Abstract

Gamma-ray astronomy, which may be defined to include the spectral region from above 100 keV to about 1000 GeV, permits investigation of the most energetic photons originating in the Galaxy and beyond. These observations provide the most direct means of studying the largest transfers of energy occurring in astrophysical processes, including the dynamic effects of the energetic charged cosmic-ray particles, element synthesis, and particle acceleration. Further, gamma-rays suffer negligible absorption or scattering as they travel in straight paths. Hence they may survive billions of years. Studies of the spatial, temporal, and energy distribution of cosmic gamma-rays will, therefore, provide fundamental new information for resolving some of the major problems in astrophysics today. Attention is given to the gamma-ray observations of the solar system, stellar objects, diffuse gamma-ray emission from the Galaxy, other galaxies and cosmology, and future prospects.

Published
1978

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