Search

Your search keyword '"Stone, N."' showing total 2,503 results
Start Over Author "Stone, N."
2,503 results on '"Stone, N."'

224. Nicole: New on-line orientation facility at ISOLDE/CERN

Author

Eder, R., Berkers, I., Brown, D. E., Grand, I. S., Hagn, E., Harding, P., Hassani, R., Herzog, P., Kastelein, B., Knipper, A., Marguier, G., Massao, M., Ohya, S., Postma, H., Prinz, J., Richard-Serre, C., Romanski, I., Schlösser, K., Stone, N. J., Vanderpoorten, W., Vanhaverbeke, J., Vanneste, L., Wölfle, T., Zech, E., and ISOLDE Collaboration

Published
1990
Full Text
View/download PDF

227. Grid Sphere Electrodes used for Current Collection at the Positive Pole of Electrodynamic Tethers

Author

Stone, N. H and Moore, J. D

Subjects
Spacecraft Propulsion And Power
Abstract

The generation of either electrical power or propulsive thrust with an electrodynamic tether system necessarily depends on driving a return current through the system's ambient space plasma environment. An electrical connection is, therefore, required between the plasma and each end of the tether. The voltage required to drive current through the system is derived either from the orbital motion of the conducting tether through the magnetic field of the Earth, or from a high-voltage power supply that taps into an external energy source (e.g., the sun). In either case, one end of the tether will receive a positive bias. This positive bias, between the tether and the ambient plasma, allows electrons to be collected effectively with a simple, passive electrode. Passive electrode contactors offer several important advantages, including simplification of the upper end-body design and operations, minimization of system mass, and an increase of system reliability and robustness. A preliminary analysis of an inflatable Grid-Sphere end-body concept is presented that is interesting because of the potential for collecting arbitrarily large currents independent of tether length, while the device has the physical characteristics of a high area-to-mass ratio, a low drag coefficient, and simplicity. In particular, we will discuss the physics of current collection by a biased Grid-Sphere and the present state-of-the-art of materials, attainable area-to-mass ratios, and deployment techniques.

Published
2004

232. Plasma Sheath Behavior of the ProSEDS Delta II

Author

Wright, K. H, Stone, N. H, Gilchrist, B. E, Vaughn, J, and Garbe, G

Subjects
Spacecraft Propulsion And Power
Abstract

The Propulsive Small Expendable Deployer System (ProSEDS) mission is a demonstration of the orbit lowering capabilities of an electrodynamic tether. The system is sequenced through various electrical modes, involving both open circuit and closed circuit configurations, so that the performance capabilities of the system can be studied. Ionospheric electrons are collected on the upper end of the bare tether, conducted through the tether, and returned to the ionosphere at the lower end (Delta I1 2nd stage) via the operation of a Hollow Cathode Plasma Contactor (HCPC). The working gas of the HCPC is xenon. Environmental plasma measurements and sheath potential are obtained from the Differential Ion Flux Probe w/Mass Analysis (DIFPM) and Langmuir Probe and Spacecraft Potential (LPSP) instruments. Each instrument has three sensors symmetrically placed about the strut section of the Delta 2nd stage. A magnetometer is also included in the ProSEDS instrumentation suite. An initial analysis of the rocket stage sheath behavior as a function of ProSEDS configuration (open or closed circuit), ambient ionospheric density, orientation to velocity vector (ram-wake influence), and magnetic field orientation is presented. An initial assessment on how well the plasma contactor grounded the rocket stage is also presented.

Published
2003

236. STAR detector overview

Author

Ackermann, K.H., Adams, N., Adler, C., Ahammed, Z., Ahmad, S., Allgower, C., Amonett, J., Amsbaugh, J., Anderson, B.D., Anderson, M., Anderssen, E., Arnesen, H., Arnold, L., Averichev, G.S., Baldwin, A., Balewski, J., Barannikova, O., Barnby, L.S., Baudot, J., Beddo, M., Bekele, S., Belaga, V.V., Bellwied, R., Bennett, S., Bercovitz, J., Berger, J., Betts, W., Bichsel, H., Bieser, F., Bland, L.C., Bloomer, M., Blyth, C.O., Boehm, J., Bonner, B.E., Bonnet, D., Bossingham, R., Botlo, M., Boucham, A., Bouillo, N., Bouvier, S., Bradley, K., Brady, F.P., Brandin, A., Brown, R.L., Brugalette, G., Burkes, M., Cadman, R.V., Caines, H., Calderón de la Barca Sánchez, M., Cardenas, A., Carr, L., Carroll, J., Castillo, J., Castro, M., Cebra, D., Chattopadhyay, S., Chen, M.L., Chen, W., Chen, Y., Chernenko, S.P., Cherney, M., Chikanian, A., Choi, B., Chrin, J., Christie, W., Coffin, J.P., Conin, L., Consiglio, C., Cormier, T.M., Cramer, J.G., Crawford, H.J., Danilov, I., Dayton, D., DeMello, M., Deng, W.S., Derevschikov, A.A., Dialinas, M., Diaz, H., DeYoung, P.A., Didenko, L., Dimassimo, D., Dioguardi, J., Drancourt, C., Dietel, T., Draper, J.E., Dunin, V.B., Dunlop, J.C., Eckardt, V., Edwards, W.R., Efimov, L.G., Eggert, T., Emelianov, V., Engelage, J., Eppley, G., Erazmus, B., Etkin, A., Fachini, P., Faine, V., Feliciano, C., Ferenc, D., Ferguson, M.I., Fessler, H., Filimonov, K., Finch, E., Fisyak, Y., Flierl, D., Flores, I., Foley, K.J., Fritz, D., Fu, J., Gagliardi, C.A., Gagunashvili, N., Gans, J., Gaudichet, L., Gazdzicki, M., Germain, M., Geurts, F., Ghazikhanian, V., Gojak, C., Grabski, J., Grachov, O., Grau, M., Greiner, D., Greiner, L., Grigoriev, V., Grosnick, D., Gross, J., Guedon, M., Guilloux, G., Gushin, E., Hall, J., Hallman, T.J., Hardtke, D., Harper, G., Harris, J.W., Heffner, M., Heppelmann, S., Herston, T., Hill, D., Hippolyte, B., Hirsch, A., Hjort, E., Hoffmann, G.W., Horsley, M., Howe, M., Huang, H.Z., Humanic, T.J., Hümmler, H., Hunt, W., Hunter, J., Igo, G., Ishihara, A., Ivanshin, Yu.I., Jacobs, P., Jacobs, W.W., Jacobson, S., Janik, M., Jared, R., Jensen, P., Johnson, I., Jones, P.G., Judd, E.G., Kaneta, M., Kaplan, M., Keane, D., Khodinov, A., Kiryluk, J., Kisiel, A., Klay, J., Klein, S.R., Klyachko, A., Koehler, G., Konstantinov, A.S., Kotov, I., Kopytine, M., Kotchenda, L., Kovalenko, A.D., Kramer, M., Kravtsov, P., Krueger, K., Krupien, T., Kuczewski, P., Kuhn, C., Kulikov, A.I., Kunde, G.J., Kunz, C.L., Kh. Kutuev, R., Kuznetsov, A.A., Lakehal-Ayat, L., Lamont, M.A.C., Landgraf, J.M., Lange, S., Lansdell, C.P., Lasiuk, B., Laue, F., Lebedev, A., LeCompte, T., Lednický, R., Leonhardt, W.J., Leontiev, V.M., LeVine, M.J., Li, Q., Liaw, C.-J., Lin, J., Lindenbaum, S.J., Lindenstruth, V., Lindstrom, P.J., Lisa, M.A., Liu, F., Liu, L., Liu, Z., Liu, Q.J., Ljubicic, T., Llope, W.J., LoCurto, G., Long, H., Longacre, R.S., Lopez-Noriega, M., Love, W.A., Lynn, D., Maier, R., Majka, R., Margetis, S., Markert, C., Martin, L., Marx, J., Matis, H.S., Matulenko, Yu.A., McParland, C., McShane, T.S., Meier, J., Meissner, F., Melnick, Yu., Meschanin, A., Messer, M., Middlekamp, P., Miller, B., Miller, M.L., Milosevich, Z., Minaev, N.G., Minor, B., Mitchell, J., Mogavero, E., Moiseenko, V.A., Moltz, D., Moore, C.F., Morozov, V., de Moura, M.M., Munhoz, M.G., Mutchler, G.S., Nelson, J.M., Nevski, P., Nguyen, M., Nguyen, T., Nikitin, V.A., Nogach, L.V., Noggle, T., Norman, B., Nurushev, S.B., Nussbaum, T., Nystrand, J., Odyniec, G., Ogawa, A., Ogilvie, C.A., Okorokov, V., Olchanski, K., Oldenburg, M., Olson, D., Ott, G., Padrazo, D., Paic, G., Pandey, S.U., Panebratsev, Y., Panitkin, S.Y., Pavlinov, A.I., Pawlak, T., Perevoztchikov, V., Peryt, W., Petrov, V.A., Pinganaud, W., Pirogov, S., Platner, E., Pluta, J., Polk, I., Porile, N., Porter, J., Poskanzer, A.M., Potrebenikova, E., Prindle, D., Pruneau, C., Puskar-Pasewicz, J., Rai, G., Rasson, J., Ravel, O., Ray, R.L., Razin, S.V., Reichhold, D., Reid, J.G., Renfordt, R.E., Retiere, F., Ridiger, A., Riso, J., Ritter, H.G., Roberts, J.B., Roehrich, D., Rogachevski, O.V., Romero, J.L., Roy, C., Russ, D., Rykov, V., Sakrejda, I., Sanchez, R., Sandler, Z., Salur, S., Sandweiss, J., Saulys, A.C., Savin, I., Schambach, J., Scharenberg, R.P., Scheblien, J., Scheetz, R., Schlueter, R., Schmitz, N., Schroeder, L.S., Schulz, M., Schüttauf, A., Schweda, K., Sedlmeir, J., Seger, J., Seliverstov, D., Seyboth, P., Seymour, R., Shahaliev, E., Shestermanov, K.E., Shimanskii, S.S., Shuman, D., Shvetcov, V.S., Skoro, G., Smirnov, N., Smykov, L.P., Snellings, R., Solberg, K., Sorensen, P., Sowinski, J., Spinka, H.M., Srivastava, B., Stephenson, E.J., Stock, R., Stolpovsky, A., Stone, N., Strikhanov, M., Stringfellow, B., Stroebele, H., Struck, C., Suaide, A.A.P., Sugarbaker, E., Suire, C., Šumbera, M., Symons, T.J.M., Szanto de Toledo, A., Szarwas, P., Tai, A., Takahashi, J., Tang, A.H., Tarchini, A., Tarzian, J., Thomas, J.H., Thompson, M., Tikhomirov, V., Tokarev, M., Tonjes, M.B., Tonse, S., Trainor, T.A., Trentalange, S., Tribble, R.E., Trofimov, V., Tsai, O., Turner, K., Ullrich, T., Underwood, D.G., Vakula, I., Van Buren, G., VanderMolen, A.M., Vanyashin, A., Vasilevski, I.M., Vasiliev, A.N., Vigdor, S.E., Visser, G., Voloshin, S.A., Vu, C., Wang, F., Ward, H., Watson, J.W., Weerasundara, D., Weidenbach, R., Wells, R., Wenaus, T., Westfall, G.D., Whitfield, J.P., Whitten, C., Jr., Wieman, H., Willson, R., Wilson, K., Wirth, J., Wisdom, J., Wissink, S.W., Witt, R., Wolf, J., Wood, J., Xu, N., Xu, Z., Yakutin, A.E., Yamamoto, E., Yang, J., Yepes, P., Yokosawa, A., Yurevich, V.I., Zanevski, Y.V., Zborovský, I., Zhang, H., Zhang, W.M., Zimmerman, D., Zoulkarneev, R., and Zubarev, A.N.

Published
2003
Full Text
View/download PDF

237. Current-Produced Magnetic Field Effects on Current Collection

Author

Khazanov, George V, Stone, N. H, and Whitaker, Ann F

Subjects
Plasma Physics
Abstract

Current collection by an infinitely long, conducting cylinder in a magnetized plasma, taking into account the magnetic field of the collected current, is discussed. A region of closed magnetic surfaces disconnects the cylinder from infinity. Due to this, the collected current depends on the ratio between this region and the plasma sheath region and, under some conditions, current reduction arises. The current collection along a realistic "bare wire" space tether is considered. A number of factors are taken into account, including the resistance of the wire and shielding resulting from the current-induced magnetic field produced by current flow in the tether. The plasma density, tether length and radius, the geomagnetic field strength and angle to the orbital velocity vector were all used as parameters in the study. It is shown that magnetic shielding for certain tether system configurations, when combined with particular values of the governing parameters, significantly reduces the collected current. Specifically, it is shown that an electrodynamic tether in the "thruster" mode suffers greater reduction from magnetic shielding than a tether with the same characteristics deployed in the "generator" mode. We find that, for both modes, current-induced magnetic shielding becomes more significant as plasma density and wire radius increase. The same is true for the dependence on the angle of the geomagnetic field to the orbital velocity vector and the motion-induced electric field for the generator mode For the thruster mode, the effect is larger for smaller angles. In both operating modes, the shielding is more important for smaller angles between the tether and magnetic field. In addition to the above dependencies, the effect for the thruster mode essentially depends on the tether length. In general, any parametric change that increases tether current, relative to the strength of the electric field between the tether and the ambient plasma, will increase the shielding effect (thereby reducing overall tether current compared to the case without considering these effects). The effect of the induced magnetic shielding can be significant in some cases.

Published
2002

244. Ion Temperature Enhancement in the Wakes of Ionospheric Spacecraft

Author

Samir, U, Israelevich, P, Wright, K. H., Jr, and Stone, N. H

Subjects
Plasma Physics
Abstract

Enhancements of the temperature of electrons in spacecraft plasma wakes have been reported for numerous cases, and this phenomenon has been discussed both empirically and theoretically. However, very few measurements seem to have been made of the ion temperature within plasma wakes, possibly because the great majority of ion measurements were focused on obtaining geophysical parameters and hence were confined to the region ahead of the spacecraft. Recently, however, an enhancement of the temperature of ions was discovered in data obtained in the wake of the space shuttle during the Spacelab 2 mission. At the time of that publication this was the only known observation of this type. Herein we report an additional case of ion temperature enhancement in a plasma wake. The data were taken during the tethered satellite system reflight (TSS-IR) mission in the wake of the tethered satellite during passive (no current flow) operations. The measurements were obtained with the Differential Ion Flux Probe.

Published
2001
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results