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  • 1
    Electronic Resource
    Electronic Resource
    Beam breakup growth and reduction experiments in long-pulse electron beam transport (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 1258-1266 
    Details
    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: http://dx.doi.org/10.1063/1.356429
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  • 2
    Electronic Resource
    Electronic Resource
    The beam breakup instability in quadrupole and solenoidal electron-beam transport systems (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 3091-3102 
    Details
    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: http://dx.doi.org/10.1063/1.351000
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  • 3
    Electronic Resource
    Electronic Resource
    Deflection of carbon dioxide laser and helium-neon laser beams in a long-pulse relativistic electron beam diode (1991)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 62 (1991), S. 1776-1782 
    Details
    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: http://dx.doi.org/10.1063/1.1142421
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  • 4
    Electronic Resource
    Electronic Resource
    Measurement of long-pulse relativistic electron beam perpendicular- to-parallel velocity ratio by Cerenkov emission and radiation darkening on a glass plate (1992)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 1671-1675 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We report measurements of the ratio of the perpendicular velocity to the parallel velocity, α= v⊥ /v(parallel), of a relativistic electron beam gyrating in a magnetic field by the use of (1) Cerenkov emission from a glass plate, detected by a gated microchannel plate image intensifier camera, and (2) electron-beam-induced radiation darkening pattern on the same glass plate. The measurements are based on a direct determination of the Larmor radius of an electron beam of known energy. Experiments were performed on a long-pulse electron beam accelerator with e-beam diode parameters: VD = 0.6–0.9 MV, pulse length=0.5–1 μs, ID = 1–10 kA. The experimental value of α agrees with simulation results from particle trajectory codes as well as theoretical predictions from Busch's theorem and adiabatic theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143321
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  • 5
    Electronic Resource
    Electronic Resource
    Pencil-like mm-size electron beams produced with linear inductive voltage adders (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 70 (1997), S. 832-834 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present the design, analysis, and results of the high brightness electron beam experiments currently under investigation at Sandia National Laboratories. The anticipated beam parameters are the following: energy 12 MeV, current 35–40 kA, rms radius 0.5 mm, and pulse duration 40 ns full width at half-maximum. The accelerator is SABRE, a pulsed linear inductive voltage adder modified to higher impedance, and the electron source is a magnetically immersed foilless electron diode. 20–30 T solenoidal magnets are required to insulate the diode and contain the beam to its extremely small-sized (1 mm) envelope. These experiments are designed to push the technology to produce the highest possible electron current in a submillimeter radius beam. Design, numerical simulations, and experimental results are presented. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.118217
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  • 6
    Electronic Resource
    Electronic Resource
    Microwave growth from the beam breakup instability in long-pulse electron beam experiments (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 61 (1992), S. 642-644 
    Details
    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: http://dx.doi.org/10.1063/1.107808
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  • 7
    Electronic Resource
    Electronic Resource
    Zur papierchromatographischen trennung der platinmetalle unter besonderer berucksichtigung des osmiums - 1. Teil. alkohole, ketone und ather als fliessmittel
    Amsterdam : Elsevier
    Journal of Chromatography A 44 (1969), S. 362-373 
    Details
    ISSN: 0021-9673
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0021-9673(01)92547-6
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  • 8
    Electronic Resource
    Electronic Resource
    Zur papierchromatographischen trennung der platin-metalle unter besonderer berucksichtigung des osmiums - 2. Teil. Mischsysteme und salze als fliessmittel
    Amsterdam : Elsevier
    Journal of Chromatography A 44 (1969), S. 374-382 
    Details
    ISSN: 0021-9673
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0021-9673(01)92548-8
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  • 9
    Electronic Resource
    Electronic Resource
    Zur Lösungsmittelextraktion des Rutheniums aus wäßrigen chlor- und bromwasserstoffsauren Lösungen. II (1969)
    Springer
    Microchimica acta 57 (1969), S. 1107-1113 
    Details
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary The chloro- and bromo-complexes of trivalent ruthenium can be extracted from solutions containing HCl and HBr less well by orders of magnitude as compared with the corresponding osmium complexes. The extraction agents are graded in their action as follows: amines (DBA) 〉 organophosphorus compounds (TBP, TOPO etc.) 〉alcohols 〉ketones. Whereas there is a mechanism in the cases of the organophosphorus compounds, alcohols and ketones, as is also characteristic of the osmium extraction, the amines exhibit deviations from the corresponding osmium extraction. Confirmations or guide lines with respect to the procedures underlying the extraction of the acido complexes can be obtained by a consideration of the agreement with or deviations from the extraction mechanism of the ruthenium- and osmium-extraction. In addition, the extraction capability, which is absent in some extractants, can be employed when working out extraction procedures, for example, for the osmium/ruthenium separation.
    Notes: Zusammenfassung Die Chloro- und Bromokomplexe des dreiwertigen Rutheniums können aus HCl- und HBr-haltigen Lösungen um Größenordnungen schlechter als die entsprechenden Komplexe des Osmiums extrahiert werden. Die Extraktionsmittel sind nach ihrer Wirkung wie folgt abgestuft: Amine (DBA) 〉 Organophosphorverbindungen(TBP,TOPOu.a.) 〉 Alkohole 〉 〉 Ketone. Während bei den Organophosphorverbindungen, Alkoholen und Ketonen ein Mechanismus vorliegt, wie er auch für die Osmiumextraktion charakteristisch ist, zeigen die Amine Abweichungen von der entsprechenden Osmiumextraktion. Durch die Übereinstimmung bzw. Abweichungen des Extraktionsmechanismus der Ruthenium- und Osmiumextraktion können Bestätigungen bzw. Hinweise für die den Extraktionen der Acidokomplexe zugrunde liegenden Vorgänge gewonnen werden. Außerdem kann die mit einigen Extraktionsmitteln fehlende Extraktionsfähigkeit bei Ausarbeitung von Trennvorschriften, z. B. für die Osmium/Ruthenium-Trennung, genutzt werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01219256
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  • 10
    Electronic Resource
    Electronic Resource
    Zur Anwendung der Elektronenstrahl-Röntgenmikroanalyse in der Spurenanalyse (1970)
    Springer
    Microchimica acta 58 (1970), S. 61-70 
    Details
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary The electron beam-roentgen microanalysis employed in numerous areas of study has hitherto found no application in trace analysis despite the finding that the detection limit goes as low as 10−14 g. Consequently, a microelectrolysis cell has now been developed that permits the deposition of trace constituents on electrode surfaces whose areas approximate only 0.0003 mm2 and also the transfer of the substances concentrated on tiny surfaces into the electron beam microanalyzer. By means of roentgen spectrograms, that were measured with a device made up of a commercial electron microscope combined with a roentgen spectrometer, it was shown that, with the aid of the above concentration procedure, it is feasible to accomplish a roentgen spectroscopic identification of trace elements in amounts whose order of magnitude is 10−9 g. This procedure is doubtless subject to improvements and hence a lowering of the detection limit is a proper topic for discussion.
    Notes: Zusammenfassung Die auf vielen Gebieten eingesetzte Elektronenstrahl-Röntgenmikroanalyse findet trotz der bis 10−14 g reichenden Nachweisgrenze bisher in der Spurenanalyse keine Anwendung. Deshalb wurde eine Mikroelektrolysezelle entwickelt, die eine Abscheidung von Spurenbestand teilen auf Elektrodenoberflächen von etwa 0,0003 mm2 sowie eine Überführung der auf kleinster Fläche konz. Substanzen in den Elektronen strahl-Mikroanalysator erlaubt. An Hand von Röntgenspektrogrammen, die mit einer aus einem kommerziellen Elektronenmikroskop und einem Röntgenspektrometerzusatz bestehenden Anordnung gemessen wurden, wird gezeigt, daß mit Hilfe des Konzentrierungsverfahrens eine röntgenspektroskopische Identifizierung von Metallspuren in der Größenordnung von 10−9 g möglich ist. Da das angewandte Verfahren verbessert werden kann, scheint eine weitere Herabsetzung der Nachweisgrenze diskutierbar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01218097
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