Search Results - (Author, Cooperation:R. Bosch)

Showing 1 - 20 results of 56, query time: 0.26s Refine Results
  1. 1
    Staff View
    Publication Date:
    2018-01-03
    Publisher:
    Rockefeller University Press
    Print ISSN:
    0022-1007
    Electronic ISSN:
    1540-9538
    Topics:
    Medicine
    Keywords:
    Infectious Disease and Host Defense
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  2. 2
    R. Bosch ; M. van de Pol ; J. Philp
    Nature Publishing Group (NPG)
    Published 2015
    Staff View
    Publication Date:
    2015-08-01
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Agriculture/statistics & numerical data ; Biofuels/supply & distribution/utilization ; *Biomass ; Conservation of Natural Resources/*methods ; Environmental Policy/*trends ; *International Cooperation ; Plant Oils/supply & distribution ; *Policy Making
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Staff View
    Publication Date:
    2013-04-06
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    African Americans/genetics ; Alleles ; Amino Acid Sequence ; Anti-Retroviral Agents/therapeutic use ; Crohn Disease/genetics/immunology ; *Gene Expression Regulation ; HIV/genetics/*immunology ; HIV Infections/drug therapy/*genetics/*immunology ; HLA-C Antigens/*genetics ; Humans ; Immunodominant Epitopes/genetics ; Molecular Sequence Data ; Mutation ; Peptide Fragments/immunology ; Polymorphism, Single Nucleotide ; T-Lymphocytes, Cytotoxic/*immunology ; Viral Load/genetics
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  4. 4
    Staff View
    Publication Date:
    2018-06-22
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Geosciences
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Astronomy, Physics
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  5. 5
    Bosch, R. A. ; Menge, P. R. ; Gilgenbach, R. M.

    [S.l.] : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Dispersion relations are derived to determine the growth rate, dominant wavelength, and group velocity of disturbances caused by the beam breakup instability. Considerations include weak and strong focusing, x-y coupling in solenoidal transport, the spacing of accelerator cavities, and periodically pulsed beams. Beam breakup growth is minimum when the cavity spacing equals an integral number of half-betatron wavelengths for quadrupole focusing, and an integral number of betatron wavelengths for solenoidal focusing. Minimum growth is also found for periodic pulses separated by an integral number of half-periods of the TM110 cavity mode. Expressions for beam breakup growth at the minima are obtained.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  6. 6
    Failor, B. H. ; Gabl, E. F. ; Busch, G. E. ; Bosch, R. A. ; Gerber, G. L. ; Armentrout, C. J.

    [S.l.] : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    The development of intense x-ray sources and sensitive gated detectors is needed for the diagnosis of ICF implosions. A laser plasma x-ray source, with an instantaneous power of 200–500 MW in the range 2.7–3 keV, was used to evaluate a specific detector configuration. The detector, consisting of a PET crystal and a MCP framing camera, was used to obtain radiographs of NaCl-doped targets. Applications are currently signal limited, indicating the need for brighter x-ray sources and/or more sensitive detection systems.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  7. 7
    Menge, P. R. ; Gilgenbach, R. M. ; Lau, Y. Y. ; Bosch, R. A.

    [S.l.] : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The results of an experimental program whose sole objective is to investigate the cumulative beam breakup instability (BBU) in electron beam accelerators are presented. The BBU growth rate scalings are examined with regard to beam current, focusing field, cavity Q, and propagation distance. A microwave cavity array was designed and fabricated to excite and measure the cumulative BBU resulting from beam interactions with the deflecting TM110 cavity mode. One phase of this experiment used high Q(≈1000) cavities with relatively large frequency spread (Δf/f0≈0.1%). The observed TM110 mode microwave growth between an upstream (second) and a downstream (tenth) cavity indicated BBU growth of 26 dB for an electron beam of kinetic energy of 750 keV, 45 A, and focused by a 1.1 kG solenoidal field. At beam currents of less than 100 A the experiments agreed well with a two-dimensional continuum theory; the agreement was worse at higher beam currents ((approximately-greater-than)100 A) due to beam loading. The second-phase experiments used lower Q(≈200) cavities with relatively low frequency spread (Δf/f0≈0.03%). Theory and experiment agreed well for beam currents up to 220 A. Distance scaling experiments were also performed by doubling the propagation length. Instability growth reduction experiments using the technique of external cavity coupling resulted in a factor of four decrease in energy in BBU growth when seven internal beam cavities were coupled by microwave cable to seven identical external dummy cavities. A theory invoking power sharing between the internal beam cavities and the external dummy cavities was used to explain the experimental reduction with excellent agreement using an equivalent circuit model.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  8. 8
    Bosch, R. A. ; Gilgenbach, R. M.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    In solenoidal beam transport systems, motions in the x and y directions are coupled by the v×B force. A two-dimensional coupled mode description of the beam breakup (BBU) instability is presented; its dispersion relation is derived and compared with the one-dimensional BBU dispersion relation. In the two-dimensional description, instability growth is doubled and two additional wave modes are found in the regime of strong focusing. In the weak focusing regime, the two-dimensional description gives the same dispersion relation as the one-dimensional model.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  9. 9
    Bosch, R. A. ; Merlino, R. L.

    [S.l.] : American Institute of Physics (AIP)
    Published 1986
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The confinement properties of a low-β (average) potassium plasma produced by contact ionization in a spindle cusp magnetic field were investigated. In this configuration, ne≈108–1010 cm−3, Te≈Ti≈0.2 eV, and the ions are weakly magnetized. Electron and ion densities, space potentials, and plasma flow velocities were measured in the ring and point cusps. The leak width of the escaping plasma was measured over a wide range of magnetic field strengths and neutral pressures. The dependence of the leak width on neutral pressure and magnetic field strength is accounted for by a simple model in which the plasma streams out of the cusps along the magnetic field lines while diffusing across the magnetic field due to the combined effects of neutral-particle collisions and Bohm diffusion. Measurements of broadband plasma noise suggest the presence of ion acoustic wave turbulence.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  10. 10
    Bidwell, S. W. ; Bosch, R. A. ; Gilgenbach, R. M.

    [S.l.] : American Institute of Physics (AIP)
    Published 1989
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The combustion rate of premixed gases in a closed vessel was increased by injecting a high-current electron beam into the gas mixture within about 20 ms of spark ignition. This effect was observed with the fuels ethylene, methane, ethane, propane, and n-butane. Experimental results provide strong evidence that e-beam excitation of the fundamental longitudinal-acoustic mode of the cylindrical chamber is the mechanism of combustion enhancement. An observable combustion enhancement required that the amplitude of the fluid velocity oscillation in this acoustic mode be greater than or approximately equal to the flame propagation speed and was associated with a wrinkled or cellular flame structure with dimensions on the order of 1/2 cm. These results are in good agreement with values for the threshold acoustic velocity amplitude and dimension of cellular structure predicted for a periodically accelerated flame.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  11. 11
    Gilgenbach, R. M. ; Bidwell, S. W. ; Bosch, R. A. ; Brake, M. L. ; Tucker, J. E. ; Repetti, T. E. ; Sell, J. A.

    [S.l.] : American Institute of Physics (AIP)
    Published 1987
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Results are presented of the first experiments in which high-current electron beam injection is shown to modify the combustion of both lean and rich ethylene-air mixtures. The rate of pressure rise in the chamber increases by up to a factor of 2 and flame speed increases by 40%–50% for cases in which an electron beam is injected into a spark-ignited nonstoichiometric ethylene-air mixture. Spectroscopic emission from the flame is modified by electron beam injection with more rapid rise and decay of OH line emission. Further research is needed to identify the cause of the observed enhancement in combustion rate.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  12. 12
    Bosch, R. A.

    [S.l.] : American Institute of Physics (AIP)
    Published 2002
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    Edge radiation may be extracted by a slotted mirror located within a straight section of the Aladdin electron storage ring. For wavelengths exceeding 1 mm, this method is expected to provide a greater flux than a large aperture located downstream of a straight section or bending magnet source. The edge radiation within an Aladdin straight section may find application as a broadband source for wavelengths of 1 μm–60 mm, or as a diagnostic of the bunch length through coherent emission. © 2002 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  13. 13
    Bosch, R. A. ; May, T. E. ; Reininger, R. ; Green, M. A.

    [S.l.] : American Institute of Physics (AIP)
    Published 1996
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    The infrared radiation emitted by electrons entering or exiting a storage ring bending magnet, which is termed "edge'' radiation, is computed. The numerical results are in agreement with experimental observations at a wavelength of 1 μm. A comparison is made with the infrared synchrotron radiation emitted from the central region of a bending magnet for wavelengths of 1 μm–1000 μm. The flux of the edge radiation is lower than that of the synchrotron radiation for the shorter wavelengths studied, and greater for the longer wavelengths. However, the brightness of the edge radiation is higher for all of the wavelengths studied. This suggests that edge radiation may be a promising infrared radiation source. © 1996 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  14. 14
    Bosch, R. A. ; Ching, H. ; Gilgenbach, R. M. ; Ventzek, P. L. G. ; Menge, P. R. ; Choi, J. J. ; Spencer, T. A.

    [S.l.] : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    Deflection of carbon dioxide and helium-neon laser beams has been used to measure plasma and neutral density gradients during the operating mode and after the shorting time of a long-pulse field-emission electron beam diode. Plasma density gradients of (1014–1015) cm−4 were observed throughout the diode during the final microsecond of the 2–3 μs electron beam pulse. The neutral density gradient was less than 1×1018 cm−4 during the electron beam pulse. Upon diode shorting, neutral density gradients increased to (1018–1019) cm−4 over ∼1 μs, and decayed over many microseconds. Plasma density gradients of ∼1015 cm−4 were also observed after shorting. These experiments demonstrate the value of carbon-dioxide laser and helium-neon laser deflection for diagnosing plasma and neutral particles in long-pulse electron beam diodes.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  15. 15
    Menge, P. R. ; Gilgenbach, R. M. ; Bosch, R. A.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The beam breakup (BBU) instability has been investigated in high-current, long-pulse electron beams propagating through microwave cavities. Experiments are performed using a relativistic electron-beam generator with diode parameters: 0.7–0.8 MV, 1–15 kA, and 0.5–1.5 μs. The magnitude of the solenoidal magnetic field places these experiments in an intermediate regime between strong focusing and weak focusing. The electron-beam transport system consists of ten identical pillbox cavities each containing a small microwave loop antenna designed to detect the TM110 beam breakup mode. The TM110 microwave mode is primed in the first cavity by a magnetron tuned to the resonance frequency of 2.5 GHz. The BBU instability growth is measured through the amplification of the 2.5 GHz microwaves between the second and tenth cavities. Strong growth (25–38 dB) of the TM110 microwave signal is observed when the initial cavity is primed exactly on resonance, with a rapid decrease of the growth rate off-resonance. The magnitude of microwave growth is consistent with the predictions of BBU theory.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  16. 16
    Bosch, R. A. ; Berger, R. L. ; Failor, B. H. ; Delamater, N. D. ; Charatis, G. ; Kauffman, R. L.

    New York, NY : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7666
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Supersonic, counterstreaming plasmas were produced by ablating plasma from the inside surfaces of two parallel disks made of aluminum and magnesium, respectively, with a 0.53 μm laser at an intensity of 1014 W/cm2 for 1.3 nsec. Diagnostics included holographic interferometry, a time-integrated x-ray pinhole camera and a gated x-ray crystal spectrograph with imaging slits. The plasmas interpenetrate for the first half of the laser pulse but stagnate once the electron density exceeds 5×1020 cm−3. Spectroscopic measurements suggest a coronal electron temperature of ∼800 eV and an ion temperature of ∼15 keV in the stagnated plasma. The observations are in good agreement with a two ion fluid model of interpenetrating plasmas in which the dominant slowing down process is ion–ion collisions.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  17. 17
    Lucey, R. F. ; Gilgenbach, R. M. ; Miller, J. D. ; Tucker, J. E. ; Bosch, R. A.

    New York, NY : American Institute of Physics (AIP)
    Published 1989
    Staff View
    ISSN:
    1089-7666
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Results are presented for the first experiments in which long-pulse (0.4–1 μsec), relativistic (0.8 MV) electron beams have been transported in the ion focused regime (IFR) in ion channels formed in low pressure diethylaniline gas by means of KrF excimer laser-induced ionization. These experiments demonstrate that the most efficient (50%–80%) and longest pulse (0.6 μsec) e-beam transport is obtained with laser-induced channels over a very narrow gas pressure range (0.3–1.7 mTorr). Higher than optimal pressures cause excess e-beam-induced ionization and instability of the electron beam. At lower pressures, the laser-induced ion channel density is insufficient for initial e-beam guidance. Transverse oscillations of the electron beam have been measured at a frequency close to that predicted for the ion hose instability. The growth length and wavelength of the transverse oscillations are comparable to the betatron wavelength, further suggesting that these oscillations result from the ion hose instability.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  18. 18
    Bosch, R. A. ; Gilgenbach, R. M.

    [S.l.] : American Institute of Physics (AIP)
    Published 1988
    Staff View
    ISSN:
    1089-7666
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The ion hose instability in the ion-focused regime is analyzed using a rigid beam model with phenomenological damping terms. Values of the instability wavelength, e-folding length, and group velocity are calculated and compared with numerical results. The impulse response function for this model is also obtained.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  19. 19
    Bosch, R. A. ; Gilgenbach, R. M.

    [S.l.] : American Institute of Physics (AIP)
    Published 1988
    Staff View
    ISSN:
    1089-7666
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Recently, the propagation of an electron beam through an ion channel with periodically varying ion density has been proposed as a method of transporting or modulating an electron beam. A theoretical treatment indicates that, in the absence of an external magnetic field, cylindrically symmetric radial oscillations of the beam electrons are excited by the channel, with resonant excitation occurring when the wavelength of the ion density variation equals the betatron wavelength. An analysis of the ion focusing regime (IFR) ion hose instability indicates that the e-folding length of this instability increases when the variations of the electron density are increased. In the absence of an external magnetic field and damping, moderate electron density variations (caused, for example, by a periodic ion channel or the nonrigidity of the beam and channel) result in a wavelength and e-folding length on the order of the beam-averaged betatron wavelength.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  20. 20
    Prasad, M. K. ; Estabrook, K. G. ; Harte, J. A. ; Craxton, R. S. ; Bosch, R. A. ; Busch, Gar. E. ; Kollin, J. S.

    New York, NY : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7666
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The simulation of interferograms for laser fusion-type targets is described. Three-dimensional ray-tracing postprocessors to the two-dimensional hydrodynamic codes lasnex and sage are used for this purpose. Simulated interferograms can then be directly compared with experimentally obtained interferograms, thus providing insight into various aspects of target physics, such as anisotropic thermal transport and details of the hydrodynamic flow. The method is illustrated for two specific KMS microdisk target shots diagnosed with double-exposure holographic interferometry.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses